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Normal anatomy and congenital anomalies of vena cavaeGobardhan Thapa
This document discusses the normal anatomy and common congenital anomalies of the superior and inferior vena cavae. It begins with an overview of the embryological development of the vena cavae. It then describes the normal anatomy of the superior and inferior vena cavae and their major tributaries. Common congenital anomalies are then outlined, including double superior vena cavae, left-sided superior vena cava, left inferior vena cava, double inferior vena cava, azygos continuation of the inferior vena cava, and circumcaval anomalies of the left renal vein and ureter. Clinical significance is discussed for some anomalies.
Internal feature of right and left atriafarranajwa
This document provides information about the anatomy and structures of the right and left atria of the heart. It discusses the key internal features of each atrium, including chambers, valves, veins and arteries, muscle structures, and other anatomical landmarks. It also briefly explains some clinical significance of atrial structures, mentioning how abnormalities like atrial septal defects or atrial fibrillation can impact blood flow and cardiac output. The document aims to educate the reader on the basic internal structures of the atria and their relationships to clinical functions.
The coronary arteries arise from the ascending aorta and form a circulatory loop around the heart. The right coronary artery originates from the right sinus and supplies the right atrium and ventricle. The left coronary artery originates from the left sinus and divides into the left anterior descending artery and circumflex artery to supply the left side of the heart. Blood from the heart drains primarily into the coronary sinus which empties into the right atrium.
The document provides an overview of the anatomy of the heart and surrounding structures. It describes the location of the heart in the chest and its internal and external structures. These include the four chambers of the heart (right and left atria and ventricles), major blood vessels (veins and arteries), surrounding membranes (pericardium), and other anatomical details.
Arterial supply of the Abdomen : Abdominal AortaBitew Mekonnen
The document discusses the arterial supply of the gastrointestinal tract. It divides the tract into the foregut, midgut, and hindgut, and summarizes the primary arterial branch supplying each segment. The foregut is supplied by the celiac trunk, the midgut by the superior mesenteric artery, and the hindgut by the inferior mesenteric artery. It also provides details on the branching patterns and territories of the celiac trunk, superior mesenteric artery, and related vessels.
The azygos vein is an unpaired vein that drains blood from the posterior abdominal wall and posterior mediastinum. It forms in the abdomen from the union of the right ascending lumbar vein and right subcostal vein, and ascends through the aortic opening in the diaphragm into the thorax. In the thorax, it passes along the right side of the vertebral column and arches above the root of the right lung before terminating in the superior vena cava. It receives tributaries from the right posterior intercostal veins and plays an important role in connecting the superior and inferior vena cava when the SVC is obstructed.
This document discusses the anatomy and clinical applications of the coronary sinus and its tributaries. It notes that 60% of venous blood from the heart drains into the right atrium via the coronary sinus. The coronary sinus receives blood from the left coronary territory, while the anterior cardiac vein drains blood from the right coronary artery. Echocardiography, fluoroscopy, CT, and angiography can be used to image the coronary sinus and evaluate anomalies such as an absent or membranous Thebesian valve, absent tributaries, or an obstructed or dilated coronary sinus.
The document discusses the anatomy, physiology, assessment, and clinical significance of the right ventricle. Some key points include:
- The right ventricle is crescent-shaped and thinner-walled than the left ventricle. It has a higher preload and is more sensitive to changes in afterload.
- Assessment of the right ventricle includes echocardiography measures like fractional area change, TAPSE, and septal position. Hemodynamic measures include pulmonary artery pressures, pulmonary vascular resistance, and dP/dT.
- While able to accommodate volume overload, the right ventricle is poorly adapted for high pressures. Abnormalities in right ventricle size and function
Normal anatomy and congenital anomalies of vena cavaeGobardhan Thapa
This document discusses the normal anatomy and common congenital anomalies of the superior and inferior vena cavae. It begins with an overview of the embryological development of the vena cavae. It then describes the normal anatomy of the superior and inferior vena cavae and their major tributaries. Common congenital anomalies are then outlined, including double superior vena cavae, left-sided superior vena cava, left inferior vena cava, double inferior vena cava, azygos continuation of the inferior vena cava, and circumcaval anomalies of the left renal vein and ureter. Clinical significance is discussed for some anomalies.
Internal feature of right and left atriafarranajwa
This document provides information about the anatomy and structures of the right and left atria of the heart. It discusses the key internal features of each atrium, including chambers, valves, veins and arteries, muscle structures, and other anatomical landmarks. It also briefly explains some clinical significance of atrial structures, mentioning how abnormalities like atrial septal defects or atrial fibrillation can impact blood flow and cardiac output. The document aims to educate the reader on the basic internal structures of the atria and their relationships to clinical functions.
The coronary arteries arise from the ascending aorta and form a circulatory loop around the heart. The right coronary artery originates from the right sinus and supplies the right atrium and ventricle. The left coronary artery originates from the left sinus and divides into the left anterior descending artery and circumflex artery to supply the left side of the heart. Blood from the heart drains primarily into the coronary sinus which empties into the right atrium.
The document provides an overview of the anatomy of the heart and surrounding structures. It describes the location of the heart in the chest and its internal and external structures. These include the four chambers of the heart (right and left atria and ventricles), major blood vessels (veins and arteries), surrounding membranes (pericardium), and other anatomical details.
Arterial supply of the Abdomen : Abdominal AortaBitew Mekonnen
The document discusses the arterial supply of the gastrointestinal tract. It divides the tract into the foregut, midgut, and hindgut, and summarizes the primary arterial branch supplying each segment. The foregut is supplied by the celiac trunk, the midgut by the superior mesenteric artery, and the hindgut by the inferior mesenteric artery. It also provides details on the branching patterns and territories of the celiac trunk, superior mesenteric artery, and related vessels.
The azygos vein is an unpaired vein that drains blood from the posterior abdominal wall and posterior mediastinum. It forms in the abdomen from the union of the right ascending lumbar vein and right subcostal vein, and ascends through the aortic opening in the diaphragm into the thorax. In the thorax, it passes along the right side of the vertebral column and arches above the root of the right lung before terminating in the superior vena cava. It receives tributaries from the right posterior intercostal veins and plays an important role in connecting the superior and inferior vena cava when the SVC is obstructed.
This document discusses the anatomy and clinical applications of the coronary sinus and its tributaries. It notes that 60% of venous blood from the heart drains into the right atrium via the coronary sinus. The coronary sinus receives blood from the left coronary territory, while the anterior cardiac vein drains blood from the right coronary artery. Echocardiography, fluoroscopy, CT, and angiography can be used to image the coronary sinus and evaluate anomalies such as an absent or membranous Thebesian valve, absent tributaries, or an obstructed or dilated coronary sinus.
The document discusses the anatomy, physiology, assessment, and clinical significance of the right ventricle. Some key points include:
- The right ventricle is crescent-shaped and thinner-walled than the left ventricle. It has a higher preload and is more sensitive to changes in afterload.
- Assessment of the right ventricle includes echocardiography measures like fractional area change, TAPSE, and septal position. Hemodynamic measures include pulmonary artery pressures, pulmonary vascular resistance, and dP/dT.
- While able to accommodate volume overload, the right ventricle is poorly adapted for high pressures. Abnormalities in right ventricle size and function
The pericardium is a double-walled fibroserous membrane that surrounds the heart. It has a fibrous outer layer and a serous inner layer known as the epicardium. The pericardium maintains the heart's position, acts as a barrier to infection, and lubricates the space between the layers. It contains pericardial sinuses and has attachments superiorly, inferiorly, and posteriorly in the mediastinum. The pericardium receives its blood supply from branches of the phrenic and intercostal arteries and drains into veins that empty into the azygos system. It is innervated by the phrenic nerve and vagus nerve. Card
Anatomy tricuspid valve DR NIKUNJ R SHEKHADA (MBBS,MS GEN SURG ,DNB CTS SR)DR NIKUNJ SHEKHADA
This document provides an overview of the surgical anatomy of the tricuspid valve, pulmonary valve, and right ventricular outflow tract. It describes in detail the structures of the right atrium, tricuspid valve leaflets and annulus, subvalvular apparatus including the papillary muscles and chordae tendineae, and the function of the tricuspid valve. It also briefly outlines the anatomy of the pulmonary valve and right ventricle. The document is intended to educate cardiac surgeons on the relevant anatomy for surgeries involving these structures.
The superior vena cava receives deoxygenated blood from the upper body and delivers it to the right atrium. It is formed by the merging of the brachiocephalic veins and descends through the thoracic region into the right atrium. Its tributaries include the brachiocephalic veins, azygos vein, and intercostal veins. Obstruction of the superior vena cava can result in the development of collateral pathways through the azygos vein or between tributaries of the superior and inferior vena cavae.
The document discusses the embryology and anomalies of the systemic venous system. It begins by describing the normal development of the veins in a 4 week old embryo, including the vitelline, umbilical, cardinal, subcardinal, supracardinal and azygos veins. It then summarizes several anomalies of the superior vena cava including bilateral superior vena cava with normal drainage, bilateral superior vena cava with an unroofed coronary sinus, absent right superior vena cava, and retroaortic innominate vein. Diagnostic features and clinical manifestations of these anomalies are provided.
The arch of the aorta begins at the level of the sternal angle and arches over the root of the left lung in the superior mediastinum. It begins as the continuation of the ascending aorta and passes up, back, and left before turning backwards and downwards to become the descending aorta at the level of T4. It has anterior relations to the left lung and pleura and posterior relations to the trachea, esophagus, and thoracic duct. Its branches include the brachiocephalic trunk, left common carotid artery, and left subclavian artery.
The document discusses the anatomy of the upper limb, brachial plexus, and scapular region. The brachial plexus is formed by the lower cervical and upper thoracic spinal nerves and provides motor and sensory innervation to the upper limb. It is located in the axilla and gives rise to the major nerves of the arm. The axillary artery originates from the subclavian artery and gives rise to vessels that supply the upper limb before terminating as the brachial artery in the arm. Veins in the upper limb drain into the axillary and brachial veins. Key muscles of the scapular region include the deltoid, teres major, triceps brachii
Regional anatomy of the human thorax rs-2011AHS_anatomy2
The document provides an overview of the anatomy of the thorax, including its boundaries, regions, and contents. It describes the thoracic wall and its superficial and deep structures. It then details the different regions of the mediastinum, including the superior, inferior (anterior, middle, and posterior), and their respective contents such as veins, nerves, arteries, and organs. Key structures discussed include the lungs, heart, esophagus, thoracic aorta, trachea, and thoracic duct.
right ventricle internal and external features-
interior is divided into inflowing and outflowing parts (infundibulum)
inflowing part is rough due to trabeculae corneae, - ridges, bridges, pillars. Chordae tendineae- are attached to pillars and cusps of tricuspid valve.
outflowing part is smooth, semilunar valve guards opening of pulmonary valve
The aortic valve has three leaflets (cusps) and is located between the left ventricle and the ascending aorta. It has important relationships with surrounding structures like the mitral valve, ventricular septum, and conduction bundles. The leaflets are attached to fibrous structures like the annulus, sinuses of Valsalva, and sinotubular junction. On echocardiogram, the aortic valve can be seen opening and closing from the parasternal long and short axis views. The document provides details on the anatomy, embryology, histology, and imaging of the aortic valve.
The document describes the muscles and nerves of the thoracic wall. It discusses the three layers of intercostal muscles - external, internal, and innermost. It also describes the intercostal nerves, noting the typical arrangement from T3-T6, and variations in other regions. Finally, it discusses the diaphragm muscle, its origins along the ribs and vertebrae, openings, nerve supply, and role in respiration.
The pericardium is a fibroserous sac that surrounds the heart and roots of the great vessels. It has two layers - an outer fibrous layer and inner serous layer. The serous layer further divides into the parietal layer lining the fibrous sac and visceral layer adhered to the heart. Between these layers is the pericardial cavity containing fluid. The pericardium functions to support and protect the heart while allowing movement. Conditions like pericarditis or excess fluid accumulation can lead to cardiac tamponade.
The document summarizes the major veins and lymph drainage of the neck. It describes the courses and tributaries of the external jugular, anterior jugular, internal jugular, and subclavian veins. It also outlines the regional cervical lymph nodes, including the occipital, retroauricular, parotid, buccal, submandibular, submental, anterior cervical, and superficial cervical nodes. Finally, it discusses the deep cervical lymph nodes located along the internal jugular vein within the carotid sheath.
anatomy of Left atrium and left ventricle of the human heartGeetanjaliKarle1
left atrium- interior of auricle is rough due to musculi pectinate, rest chamber is smooth. fossa lunate is present on septal wall. 4 pulmonary veins open on posterior wall.
left ventricle- inflowing part is rough due to mitral or bicuspid valve apparatus, trabeculae carneae.
outflowing part is smooth called infundibulum. ascending aorta starts from infundibulum. aortic valve guards opening of ascending aorta
This document discusses the blood supply of the heart. It begins by describing the origins of the main coronary arteries - the right coronary artery arises from the right coronary sinus of the aorta, while the left coronary artery arises from the left coronary sinus. It then details the branches and course of each coronary artery, including the right coronary artery supplying parts of the right atrium and ventricle while the left coronary artery supplies parts of the left atrium and ventricle. The document also discusses coronary dominance patterns and variations in coronary artery anatomy. It concludes by outlining some clinical applications like coronary angiography, angioplasty, and bypass surgery for coronary artery disease.
The document summarizes the valves of the heart, including their structure, location, and function. There are two pairs of valves: atrioventricular valves (tricuspid and bicuspid/mitral) which allow blood to flow from the atria to the ventricles, and semilunar valves (pulmonary and aortic) which allow blood to exit the ventricles. The valves have cusps that open and close to ensure one-way blood flow and prevent backflow. Issues like stenosis can cause murmurs and increase pressures on the respective chambers of the heart.
Development of superior venacava and azygous veinanuppslides
The major veins of the early embryo are the vitelline vein, umbilical vein, and cardinal veins. The portal vein is formed from parts of the right and left vitelline veins. As development continues, the left horn of the sinus venosus and left hepatocardiac channel disappear. The left umbilical vein remains to carry blood from the placenta to the liver via the ductus venosus. The superior vena cava develops from the right common cardinal vein and right anterior cardinal vein. The azygos vein forms from the right azygos line and part of the right posterior cardinal vein.
Blood supply of upper limb by Dr-Ismail KhanDr-Ismail Khan
The document summarizes the arterial supply of the upper limb. It describes the axillary artery, its parts, branches and relations. It discusses the arterial anastomoses around the shoulder joint. It then describes the brachial artery, its branches including the profunda brachii artery, and the arterial anastomoses around the elbow joint. It concludes by outlining the radial and ulnar arteries, their branches and relations, and the formation of the superficial and deep palmar arches in the hand.
The document summarizes the development of the major veins in the human embryo. In the 5th week, the vitelline, umbilical and cardinal veins are distinguished. The vitelline veins carry blood from the yolk sac to the liver and form parts of the portal vein and inferior vena cava. The umbilical veins carry oxygenated blood from the placenta to the liver via the ductus venosus. The cardinal veins initially drain the embryo but are later replaced by the subcardinal, supracardinal and sacrocardinal veins, which form parts of the major veins like the renal vein, inferior vena cava and common iliac veins.
The document describes the anatomy of the pericardium and heart. It notes that the pericardium is a double-walled sac that surrounds the heart and consists of an outer fibrous layer and inner serous layer. The heart lies within the fibrous pericardium but outside the serous pericardium. The document then describes the internal structures of the right atrium, right ventricle, left atrium, and left ventricle. It provides details on the chambers, borders, surfaces, valves, and other features of the heart.
The document provides an overview of the anatomy of the heart. It describes the heart as a hollow muscular organ divided into four chambers - the right and left atria and ventricles. Each chamber is then described in detail, including its size, location within the heart, internal structures like valves and openings, and relations to other cardiovascular structures. Key components summarized include the four chambers, their internal structures like valves and openings, and basic relations to surrounding areas in the thoracic cavity.
The human heart is a muscular organ that pumps blood through the body. It is divided into four chambers - two atria that receive blood and two ventricles that pump blood out. The right side receives deoxygenated blood from the body and pumps it to the lungs. The left side receives oxygenated blood from the lungs and pumps it out to the body through the aorta. Valves control the direction of blood flow between the chambers and vessels. The heart is a vital organ that circulates blood continuously through two circuits - pulmonary circulation to the lungs and systemic circulation to the body.
The pericardium is a double-walled fibroserous membrane that surrounds the heart. It has a fibrous outer layer and a serous inner layer known as the epicardium. The pericardium maintains the heart's position, acts as a barrier to infection, and lubricates the space between the layers. It contains pericardial sinuses and has attachments superiorly, inferiorly, and posteriorly in the mediastinum. The pericardium receives its blood supply from branches of the phrenic and intercostal arteries and drains into veins that empty into the azygos system. It is innervated by the phrenic nerve and vagus nerve. Card
Anatomy tricuspid valve DR NIKUNJ R SHEKHADA (MBBS,MS GEN SURG ,DNB CTS SR)DR NIKUNJ SHEKHADA
This document provides an overview of the surgical anatomy of the tricuspid valve, pulmonary valve, and right ventricular outflow tract. It describes in detail the structures of the right atrium, tricuspid valve leaflets and annulus, subvalvular apparatus including the papillary muscles and chordae tendineae, and the function of the tricuspid valve. It also briefly outlines the anatomy of the pulmonary valve and right ventricle. The document is intended to educate cardiac surgeons on the relevant anatomy for surgeries involving these structures.
The superior vena cava receives deoxygenated blood from the upper body and delivers it to the right atrium. It is formed by the merging of the brachiocephalic veins and descends through the thoracic region into the right atrium. Its tributaries include the brachiocephalic veins, azygos vein, and intercostal veins. Obstruction of the superior vena cava can result in the development of collateral pathways through the azygos vein or between tributaries of the superior and inferior vena cavae.
The document discusses the embryology and anomalies of the systemic venous system. It begins by describing the normal development of the veins in a 4 week old embryo, including the vitelline, umbilical, cardinal, subcardinal, supracardinal and azygos veins. It then summarizes several anomalies of the superior vena cava including bilateral superior vena cava with normal drainage, bilateral superior vena cava with an unroofed coronary sinus, absent right superior vena cava, and retroaortic innominate vein. Diagnostic features and clinical manifestations of these anomalies are provided.
The arch of the aorta begins at the level of the sternal angle and arches over the root of the left lung in the superior mediastinum. It begins as the continuation of the ascending aorta and passes up, back, and left before turning backwards and downwards to become the descending aorta at the level of T4. It has anterior relations to the left lung and pleura and posterior relations to the trachea, esophagus, and thoracic duct. Its branches include the brachiocephalic trunk, left common carotid artery, and left subclavian artery.
The document discusses the anatomy of the upper limb, brachial plexus, and scapular region. The brachial plexus is formed by the lower cervical and upper thoracic spinal nerves and provides motor and sensory innervation to the upper limb. It is located in the axilla and gives rise to the major nerves of the arm. The axillary artery originates from the subclavian artery and gives rise to vessels that supply the upper limb before terminating as the brachial artery in the arm. Veins in the upper limb drain into the axillary and brachial veins. Key muscles of the scapular region include the deltoid, teres major, triceps brachii
Regional anatomy of the human thorax rs-2011AHS_anatomy2
The document provides an overview of the anatomy of the thorax, including its boundaries, regions, and contents. It describes the thoracic wall and its superficial and deep structures. It then details the different regions of the mediastinum, including the superior, inferior (anterior, middle, and posterior), and their respective contents such as veins, nerves, arteries, and organs. Key structures discussed include the lungs, heart, esophagus, thoracic aorta, trachea, and thoracic duct.
right ventricle internal and external features-
interior is divided into inflowing and outflowing parts (infundibulum)
inflowing part is rough due to trabeculae corneae, - ridges, bridges, pillars. Chordae tendineae- are attached to pillars and cusps of tricuspid valve.
outflowing part is smooth, semilunar valve guards opening of pulmonary valve
The aortic valve has three leaflets (cusps) and is located between the left ventricle and the ascending aorta. It has important relationships with surrounding structures like the mitral valve, ventricular septum, and conduction bundles. The leaflets are attached to fibrous structures like the annulus, sinuses of Valsalva, and sinotubular junction. On echocardiogram, the aortic valve can be seen opening and closing from the parasternal long and short axis views. The document provides details on the anatomy, embryology, histology, and imaging of the aortic valve.
The document describes the muscles and nerves of the thoracic wall. It discusses the three layers of intercostal muscles - external, internal, and innermost. It also describes the intercostal nerves, noting the typical arrangement from T3-T6, and variations in other regions. Finally, it discusses the diaphragm muscle, its origins along the ribs and vertebrae, openings, nerve supply, and role in respiration.
The pericardium is a fibroserous sac that surrounds the heart and roots of the great vessels. It has two layers - an outer fibrous layer and inner serous layer. The serous layer further divides into the parietal layer lining the fibrous sac and visceral layer adhered to the heart. Between these layers is the pericardial cavity containing fluid. The pericardium functions to support and protect the heart while allowing movement. Conditions like pericarditis or excess fluid accumulation can lead to cardiac tamponade.
The document summarizes the major veins and lymph drainage of the neck. It describes the courses and tributaries of the external jugular, anterior jugular, internal jugular, and subclavian veins. It also outlines the regional cervical lymph nodes, including the occipital, retroauricular, parotid, buccal, submandibular, submental, anterior cervical, and superficial cervical nodes. Finally, it discusses the deep cervical lymph nodes located along the internal jugular vein within the carotid sheath.
anatomy of Left atrium and left ventricle of the human heartGeetanjaliKarle1
left atrium- interior of auricle is rough due to musculi pectinate, rest chamber is smooth. fossa lunate is present on septal wall. 4 pulmonary veins open on posterior wall.
left ventricle- inflowing part is rough due to mitral or bicuspid valve apparatus, trabeculae carneae.
outflowing part is smooth called infundibulum. ascending aorta starts from infundibulum. aortic valve guards opening of ascending aorta
This document discusses the blood supply of the heart. It begins by describing the origins of the main coronary arteries - the right coronary artery arises from the right coronary sinus of the aorta, while the left coronary artery arises from the left coronary sinus. It then details the branches and course of each coronary artery, including the right coronary artery supplying parts of the right atrium and ventricle while the left coronary artery supplies parts of the left atrium and ventricle. The document also discusses coronary dominance patterns and variations in coronary artery anatomy. It concludes by outlining some clinical applications like coronary angiography, angioplasty, and bypass surgery for coronary artery disease.
The document summarizes the valves of the heart, including their structure, location, and function. There are two pairs of valves: atrioventricular valves (tricuspid and bicuspid/mitral) which allow blood to flow from the atria to the ventricles, and semilunar valves (pulmonary and aortic) which allow blood to exit the ventricles. The valves have cusps that open and close to ensure one-way blood flow and prevent backflow. Issues like stenosis can cause murmurs and increase pressures on the respective chambers of the heart.
Development of superior venacava and azygous veinanuppslides
The major veins of the early embryo are the vitelline vein, umbilical vein, and cardinal veins. The portal vein is formed from parts of the right and left vitelline veins. As development continues, the left horn of the sinus venosus and left hepatocardiac channel disappear. The left umbilical vein remains to carry blood from the placenta to the liver via the ductus venosus. The superior vena cava develops from the right common cardinal vein and right anterior cardinal vein. The azygos vein forms from the right azygos line and part of the right posterior cardinal vein.
Blood supply of upper limb by Dr-Ismail KhanDr-Ismail Khan
The document summarizes the arterial supply of the upper limb. It describes the axillary artery, its parts, branches and relations. It discusses the arterial anastomoses around the shoulder joint. It then describes the brachial artery, its branches including the profunda brachii artery, and the arterial anastomoses around the elbow joint. It concludes by outlining the radial and ulnar arteries, their branches and relations, and the formation of the superficial and deep palmar arches in the hand.
The document summarizes the development of the major veins in the human embryo. In the 5th week, the vitelline, umbilical and cardinal veins are distinguished. The vitelline veins carry blood from the yolk sac to the liver and form parts of the portal vein and inferior vena cava. The umbilical veins carry oxygenated blood from the placenta to the liver via the ductus venosus. The cardinal veins initially drain the embryo but are later replaced by the subcardinal, supracardinal and sacrocardinal veins, which form parts of the major veins like the renal vein, inferior vena cava and common iliac veins.
The document describes the anatomy of the pericardium and heart. It notes that the pericardium is a double-walled sac that surrounds the heart and consists of an outer fibrous layer and inner serous layer. The heart lies within the fibrous pericardium but outside the serous pericardium. The document then describes the internal structures of the right atrium, right ventricle, left atrium, and left ventricle. It provides details on the chambers, borders, surfaces, valves, and other features of the heart.
The document provides an overview of the anatomy of the heart. It describes the heart as a hollow muscular organ divided into four chambers - the right and left atria and ventricles. Each chamber is then described in detail, including its size, location within the heart, internal structures like valves and openings, and relations to other cardiovascular structures. Key components summarized include the four chambers, their internal structures like valves and openings, and basic relations to surrounding areas in the thoracic cavity.
The human heart is a muscular organ that pumps blood through the body. It is divided into four chambers - two atria that receive blood and two ventricles that pump blood out. The right side receives deoxygenated blood from the body and pumps it to the lungs. The left side receives oxygenated blood from the lungs and pumps it out to the body through the aorta. Valves control the direction of blood flow between the chambers and vessels. The heart is a vital organ that circulates blood continuously through two circuits - pulmonary circulation to the lungs and systemic circulation to the body.
The document provides information about the structure and function of the human heart. It is divided into sections on the right heart and left heart. The right heart receives deoxygenated blood from the body and pumps it to the lungs. The left heart receives oxygenated blood from the lungs and pumps it out to the body through the aorta to sustain the circulatory system. Key components include the right and left atria and ventricles, tricuspid and mitral valves, and major blood vessels like the vena cavae, pulmonary artery and veins, and aorta.
Clinical Applications of Chest SonographyGamal Agmy
Ultrasonography is a useful imaging technique for evaluating the chest that has several advantages over other modalities. It can be used to identify normal lung anatomy and visualize the pleura, as well as detect abnormalities. Common ultrasound findings in pneumonia include hypoechoic consolidated lung areas that may contain air or fluid bronchograms. Abscesses typically appear as round anechoic lesions that may form a capsule. Contrast-enhanced ultrasound can demonstrate enhancement of consolidated lung tissue in pneumonia.
The circulatory system consists of the heart, blood vessels, and blood. The heart pumps oxygen-rich blood received from the lungs through arteries to the body's tissues, and oxygen-poor blood returns to the heart via veins to be re-oxygenated in the lungs. The circulatory and respiratory systems work together to supply cells with oxygen and nutrients. Common disorders of the circulatory system include high blood pressure, heart attacks, and strokes, which can often be prevented through exercise, a healthy diet, weight control, and not smoking.
The circulatory system transports oxygen, nutrients, hormones, and antibodies throughout the body while removing waste. It consists of the heart, blood, and blood vessels. The heart pumps blood through three circulation loops - pulmonary circulation to the lungs, coronary circulation to the heart itself, and systemic circulation to the rest of the body. Blood travels from the heart through arteries, then into capillaries where nutrients and waste are exchanged, then into veins which return blood back to the heart.
The document describes the parts of the respiratory system and their functions:
1) It begins with the nostrils and nasal cavity, which warm and moisten inhaled air, before the trachea transports air into the two primary bronchi and bronchioles.
2) The bronchioles terminate in alveoli, which are tiny air sacs where gas exchange occurs.
3) A "bunch of grapes" model effectively represents the branching pathway that oxygen travels through the respiratory system until reaching the alveoli.
This document provides information about the anatomy and physiology of the heart. It describes the internal and external structures of the heart, including the four chambers (two atria and two ventricles), major blood vessels, and valves. It also discusses the conduction system of the heart including the sinoatrial node, atrioventricular node, bundle of His, and Purkinje fibers. The blood supply and innervation of the heart is outlined. Key points about cardiac cycle, electrocardiography, and pacemaker potentials are summarized.
The circulatory system transports oxygen, nutrients, hormones, and antibodies throughout the body using blood and blood vessels. The heart pumps blood through a double circulatory pathway - first to the lungs to receive oxygen and then throughout the body to supply tissues before returning to the heart. Blood flows from the heart through arteries, then to capillaries where exchange occurs, and returns to the heart through veins, completing the circulatory loop.
The circulatory system transports oxygen and nutrients to cells and removes waste. It consists of the heart, blood, and blood vessels. The heart pumps blood in two circuits - pulmonary circulation to the lungs and systemic circulation to the body. Blood travels from the heart through arteries, then to capillaries where exchange occurs, and returns to the heart through veins. The circulatory system forms a double pump to circulate blood continuously throughout the body.
This document summarizes several diseases that can affect the white blood cells and lymph nodes. It discusses Non-Hodgkin's lymphoma, Hodgkin's disease, tuberculosis of the lymph nodes, papillary carcinoma metastatic to lymph nodes, and multiple myeloma. For each disease, it covers what the disease is, typical clinical manifestations, diagnostic tests, and general treatment approaches.
This document provides an overview of the anatomy of the heart, including descriptions of the right atrium, left atrium, right ventricle, left ventricle, valves, conducting system, and blood supply. Key points include that the right atrium receives deoxygenated blood from the superior and inferior vena cava and pumps to the right ventricle. The left atrium receives oxygenated blood from the four pulmonary veins and pumps to the left ventricle. The right ventricle pumps to the pulmonary trunk while the left ventricle pumps to the aorta. Semilunar valves are located at the pulmonary trunk and aorta while atrioventricular valves are located between the atria and
This document provides an overview of the circulatory system including the pulmonary and systemic circulation. It describes the layers of vessel walls, including the tunica intima, tunica media, and tunica externa. The pulmonary circulation carries deoxygenated blood from the right ventricle to the lungs and oxygenated blood back to the left atrium. The systemic circulation carries oxygenated blood from the left ventricle to the body and deoxygenated blood back to the right atrium. Detailed diagrams and descriptions are provided of the arterial supply and venous return in various body regions including the head and neck, ventral cavity, and upper and lower limbs.
PTCA and CABG are two revascularization procedures used to treat coronary artery disease. PTCA involves using a balloon to open blocked arteries, while CABG uses grafts to bypass blocked arteries. PTCA has a higher risk of restenosis but is less invasive, while CABG has better long-term outcomes for multi-vessel disease but is more invasive. Factors like the number of blocked vessels, presence of diabetes, and left ventricular function help determine which procedure is most appropriate for a given patient. Guidelines provide direction on when PTCA or CABG is generally recommended based on a patient's specific condition.
The document provides guidance on performing a respiratory system examination, including:
- Surface anatomy and landmarks of the lungs and lobes
- Steps for a full examination, covering inspection, palpation, percussion, auscultation, and assessment of vocal resonance and tactile fremitus
- Descriptions of normal and abnormal breath sounds such as wheezes, crackles, stridor, and pleural rubs
- How findings on examination can indicate potential respiratory conditions such as consolidation, pleural effusion, or pneumothorax
The document provides an overview of the cardiovascular system and anatomy of the heart. It describes the heart's role in pumping blood through the pulmonary and systemic circuits. Key details include the four chambers of the heart, heart valves that ensure one-way blood flow, coronary circulation supplying the heart muscle, and cardiac cycle of contraction and relaxation.
Pulmonary circulation carries deoxygenated blood from the heart to the lungs where carbon dioxide is released and oxygen is picked up. The oxygenated blood then returns to the left atrium of the heart. Systemic circulation then carries the oxygenated blood away from the heart through arteries which branch into smaller vessels before returning deoxygenated blood to the right atrium to complete the cycle. The pathways of both pulmonary and systemic circulation are described in detail.
The circulatory system transports blood throughout the body via circulation. Blood carries oxygen, nutrients, hormones and waste products as it circulates from the heart through arteries and veins. The human circulatory system uses double circulation, where blood is pumped from the heart to the lungs to become oxygenated, then to tissues throughout the body, and back to the heart. This double circulation allows for gas and nutrient exchange to occur efficiently between the blood and body tissues.
This document discusses the blood vessels of the head and neck. It begins with an overview of the classification and structure of arteries and veins. It then describes the major arteries, including the common carotid artery, internal carotid artery, external carotid artery and its branches, and subclavian artery. It also discusses some of the major veins draining the head and neck, including the internal jugular vein and external jugular vein. Finally, it covers some clinical considerations regarding these blood vessels, such as atherosclerosis, varicose veins, lusoria, brain hemorrhage, carotid artery bruits, and carotid endarterectomy.
The document describes the anatomy and structure of the heart. It discusses the four chambers of the heart, including the right and left atria which collect blood, and the right and left ventricles which pump blood out. It describes the layers of the heart wall, including the epicardium, myocardium, and endocardium. It also discusses the valves that prevent backflow of blood, such as the tricuspid valve between the right atrium and ventricle. Blood flows from the heart through the pulmonary and systemic circuits to be oxygenated and delivered to the body.
The document provides information about the structure and function of the human heart. It is divided into sections on the right heart and left heart. The right heart receives deoxygenated blood from the body and pumps it to the lungs. The left heart receives oxygenated blood from the lungs and pumps it out to the body through the aorta to support the systemic circulation. Key components include the right and left atria and ventricles, tricuspid and mitral valves, and major blood vessels like the vena cavae, pulmonary artery and veins, and aorta.
The document provides information about the structure and function of the human heart. It is divided into sections on the right heart and left heart. The right heart receives deoxygenated blood from the body and pumps it to the lungs. The left heart receives oxygenated blood from the lungs and pumps it out to the body through the aorta to support the systemic circulation. Key components include the right and left atria and ventricles, tricuspid and mitral valves, and major blood vessels like the vena cavae, pulmonary artery and veins, and aorta.
The document describes the anatomy and structures of the heart. It discusses:
- The heart is surrounded by the pericardium, a double-walled sac that has an outer fibrous layer and inner serous layers separated by fluid.
- The heart has four chambers - two upper atria that receive blood and two lower ventricles that pump blood out. Blood flows through valves between the chambers.
- The heart wall has three layers - the outer epicardium, middle muscular myocardium, and inner endothelial endocardium.
- The heart is supplied by the right and left coronary arteries and drains into the coronary sinus vein.
- Nerves from the autonomic nervous system
The heart is a hollow, muscular organ located slightly left of center in the chest. It is surrounded by three layers of tissue - the outer fibrous pericardium, middle muscular myocardium, and inner endothelial endocardium. The heart is divided into four chambers - right atrium, right ventricle, left atrium, and left ventricle - with valves that ensure one-way blood flow. Deoxygenated blood enters the right atrium from the body and is pumped to the lungs via the right ventricle. Oxygenated blood returns to the left atrium from the lungs and is pumped back out to the body by the left ventricle.
The document summarizes the anatomy of the pericardium and heart. It describes the pericardium as a fibroserous sac that encloses the heart. It then discusses the layers of the pericardium - the fibrous pericardium and serous pericardium with its parietal and visceral layers. It also describes the surfaces, chambers, valves and conducting system of the heart.
The document describes the structure and function of the heart and circulatory system. It discusses the major veins that return deoxygenated blood to the right atrium, such as the superior and inferior vena cava. It also describes the four chambers of the heart, including the right and left atria that receive blood and the right and left ventricles that pump blood to the lungs and body. The valves such as the tricuspid and bicuspid valves prevent backflow of blood through the heart.
The document provides an overview of the human circulatory system, including:
- The heart pumps blood through vessels in a double circulatory system, with the pulmonary and systemic circuits.
- The heart has four chambers, with the right atrium and ventricle pumping to the lungs and the left pumping to the body. It is located in the mediastinum.
- Blood flows through one-way valves between the atria and ventricles, and into the pulmonary trunk and aorta.
- The cardiac conduction system coordinates heart chamber contractions for efficient blood flow.
The pericardium is a fibroserous sac that encloses and protects the heart. It has two layers - a fibrous outer layer and a serous inner layer. The heart has four chambers - right and left atria which receive blood, and right and left ventricles which pump blood out. Each chamber has a specific structure and function in the circulation. The heart also has a conducting system that generates electrical signals to coordinate contractions and pumping of the heart.
This presentation will help you to get to known about the human heart in very much clear way. It will help you alot in making your concepts clear regarding the human heart and it's functioning.
The document summarizes the anatomy of the cardio-vascular system of goats. It describes the heart which has four chambers - right atrium, right ventricle, left atrium and left ventricle. Blood enters the right atrium from the vena cava and is pumped to the right ventricle before entering the lungs via the pulmonary artery. Oxygenated blood returns from the lungs to the left atrium and is pumped to the left ventricle and then to the rest of the body via the aorta. It also outlines the major blood vessels including the aorta, anterior vena cava and posterior vena cava.
The heart is a hollow muscular organ responsible for pumping blood through the circulatory system. It has four chambers: right atrium, right ventricle, left atrium, and left ventricle. The heart is surrounded by membranes and has three layers - epicardium, myocardium, and endocardium. It is located in the chest cavity and pumps oxygenated blood received from the lungs through the left side of the heart to the entire body. The heart has four valves that prevent backflow of blood - tricuspid valve, pulmonary valve, mitral valve, and aortic valve.
The primitive blueprint for the heart and circulatory system emerged with the arrival of the third mesodermal germ layer in bilaterians. Since then, hearts in animals have evolved from a single layered tube to a multiple chambered heart in due course of time.
The document provides an overview of the anatomy of the heart, including its chambers, surfaces, borders, valves, conduction system, and blood supply. Some key points:
- The heart has 4 chambers - right and left atria, right and left ventricles. It is located in the mediastinum and covered by the pericardium.
- It has 3 surfaces - sternocostal, diaphragmatic, left surface - and 3 borders - right, left, inferior.
- The 4 valves are the tricuspid, mitral, aortic and pulmonary valves.
- The conduction system initiates and conducts electrical impulses, starting from the sinoatrial
The document provides details on the anatomy of the heart, including its chambers, valves, blood vessels, and conducting system. Some key points:
- The heart has four chambers - two atria and two ventricles. It is located slightly left of center in the chest.
- The right side receives deoxygenated blood from the body and pumps it to the lungs. The left side receives oxygenated blood from the lungs and pumps it out to the body.
- Valves separate the chambers and ensure one-way blood flow. The septum divides the left and right sides.
- The conducting system generates electrical signals that coordinate rhythmic contractions of the atria and ventricles.
Anatomy of heart dr nikunj shekhada (mbbs,ms gen surg ,dnb cts SR) 11 6-18DR NIKUNJ SHEKHADA
The document provides an overview of the anatomy of the heart. It describes the heart as a hollow muscular organ located in the middle mediastinum behind the sternum. The heart has four chambers - two atria which receive blood and two ventricles which pump blood out. It notes the positions of structures like the cardiac apex. It then describes in detail the layers of the heart wall, the structure of the atria and ventricles, surrounding tissues like the pericardium, valves, blood vessels including the coronary arteries and veins, and the electrical conduction system.
The heart is a muscular organ that pumps blood through the circulatory system. It has four chambers - two upper atria and two lower ventricles. The right side receives deoxygenated blood and pumps it to the lungs, while the left side receives oxygenated blood and pumps it out to the body. Valves prevent backflow between chambers. The heart is surrounded by membranes and layers including the pericardium. It is located in the chest cavity and has distinct surfaces and structures that allow it to efficiently circulate blood throughout the body.
This document provides an overview of heart development and comparative anatomy across vertebrates. It describes how the heart originates from mesodermal tissue and develops into a tubular structure. Across species, the heart evolves from a two-chambered structure in fish to a four-chambered heart with complete separation of oxygenated and deoxygenated blood in mammals. Key developments include the formation of four chambers, completion of the interatrial and interventricular septa, and separation of pulmonary and systemic circulation. Differences in heart structure across fish, amphibians, reptiles, birds, and mammals are also summarized.
Examville.com provides online educational resources like practice tests, live classes, tutoring, study guides, and premium content to help students prepare for exams. The document then reviews carbohydrates, including their classification, structures, functions, examples like monosaccharides, disaccharides, and polysaccharides. It also discusses topics like glycolysis, the citric acid cycle, and the biogenic roles of these metabolic pathways.
The document provides an overview of the history and approaches to the study of human anatomy. It discusses how anatomy was first formally studied in ancient Egypt and Greece. Key figures like Vesalius, Fabricius, and Harvey made important discoveries and advancements. The document also outlines the different regional, systemic, and clinical approaches to anatomy. It defines important anatomical terminology and positions. Finally, it provides details on the structure and function of skin and fascia.
The document provides detailed information about the anatomy of the head and neck region. It describes the bones that make up the skull, including the neurocranium and facial skeleton. It also discusses landmarks on the anterior, lateral, and posterior aspects of the skull. Additionally, it summarizes the muscles of facial expression and mastication, nerves and vasculature of the head and neck region, as well as structures located in the infratemporal fossa.
The document provides an overview of various cardiac medications, including their classifications, mechanisms of action, indications, and dosages. It focuses on inotropes like digoxin, chronotropes like atropine, antianginal drugs like nitroglycerin, antidysrhythmics/antiarrhythmics in the four main classes, and discusses specific drugs like quinidine, lidocaine, and flecainide. It includes examples of classroom participation questions and answers about calculating digoxin doses and the preferred route for nitroglycerin during angina attacks.
Examville is an online learning platform that provides free and premium educational resources such as practice tests, live classes, tutoring, study guides, Q&A sessions, and more to help students prepare for exams. Users can access basic functions for free or subscribe to premium content and features. The website aims to help test-takers succeed through comprehensive learning tools and support.
The nasal cavity is divided by the nasal septum into left and right cavities. Each cavity contains 4 passages formed by the nasal conchae: the sphenoethmoidal recess, superior meatus, middle meatus, and inferior meatus. The nasal cavities are lined with mucous membrane and contain paranasal sinuses. Epistaxis or nosebleeds can occur due to various causes like trauma, infections, or anatomical abnormalities. Posterior nosebleeds from Woodruff's plexus are difficult to treat due to its inaccessible location.
The document discusses the three meninges - the outer dura mater, middle arachnoid mater, and inner pia mater. It describes the layers of the dura mater, venous sinuses within the dura mater including the superior sagittal sinus, transverse sinus and sigmoid sinus, arteries that supply the dura mater, and the subarachnoid space between the arachnoid mater and pia mater. It also mentions the choroid plexus which is involved in cerebrospinal fluid production.
The document provides information about the male reproductive system. It describes the penis, scrotum, testes, epididymis, vas deferens, seminal vesicles, prostate gland, bulbourethral glands and other structures. It discusses the layers, blood supply, functions and some medical issues related to these organs.
The document summarizes the anatomy of the head and mandible bone. It describes the different parts of the skull that make up the head, including the cranium, facial bones, and three ossicles in the middle ear. It then provides a detailed overview of the mandible bone, describing its body and ramus, as well as processes like the coronoid process, condylar process, and angle. It also discusses landmarks like the mental foramen and mandibular canal.
The document summarizes the body's fluid compartments and regulation of fluid balance. It describes the extracellular and intracellular fluid compartments, how fluid moves between compartments via osmosis, and factors that can disrupt fluid balance and cause edema. Specifically, it outlines three major factors that can increase capillary fluid filtration into tissues and cause edema: increased capillary pressure, decreased plasma protein levels, and increased capillary permeability.
Examville.com is an online learning platform that provides practice tests, live classes, tutoring, study guides, Q&A, and premium content to help students prepare for exams. The document then discusses the presence of excess fluid in body tissues (edema), its intracellular and extracellular causes, and factors that can increase capillary filtration leading to extracellular edema such as increased capillary pressure, decreased plasma protein, and increased capillary permeability. Safety factors that prevent edema are also summarized.
The document discusses the adrenal glands and their hormones. It describes that the adrenal glands sit above the kidneys and contain an adrenal cortex and medulla. The cortex secretes corticosteroids like mineralocorticoids and glucocorticoids. Aldosterone is the main mineralocorticoid produced in the zona glomerulosa, while cortisol is the primary glucocorticoid from the zona fasciculata. Cortisol regulates blood glucose and its secretion is controlled by ACTH. The document also outlines the functions of aldosterone in regulating sodium, potassium, and blood pressure.
The document discusses the pancreas and its role in regulating blood glucose levels through the hormones insulin, glucagon, and somatostatin. It describes how insulin promotes glucose and fat storage while glucagon has the opposite effect of raising blood glucose. Diabetes results from insufficient insulin or insensitivity to its effects and can cause various health complications if not managed properly through diet, exercise, medication and insulin administration. The key roles of the pancreas and these hormones in maintaining blood glucose homeostasis are summarized.
The document provides information about the female reproductive system, including the ovaries, fallopian tubes, uterus, vagina, and mammary glands. It describes the structure and functions of these organs, such as follicular development in the ovaries, changes in the endometrium through the menstrual cycle, roles of the placenta in pregnancy, and hormonal control of lactation.
The document discusses perspectives on the protective and regulatory roles of renal autoregulation mechanisms. It suggests the primary purpose of the myogenic response is to protect the kidney from hypertension, not regulate renal function. Evidence indicates autoregulation protects against hypertensive injury by maintaining glomerular capillary pressure. While regulatory functions aim to stabilize renal blood flow and filtration, protection has different requirements and the myogenic response directly senses pressure changes.
The document discusses various topics related to lipids and their metabolism, including the properties and reactions of triacylglycerols, cholesterol metabolism and its role in atherosclerosis, ketone body formation and their role as an energy source, particularly for the brain during periods of starvation. Atherosclerosis results from elevated cholesterol levels, especially LDL cholesterol, and diet and exercise can help lower cholesterol. Ketone bodies are produced from fatty acids and certain amino acids in the liver during periods of fasting or low carbohydrate availability and serve as an energy source.
Examville.com provides online practice tests, live classes, tutoring, study guides, Q&A, and premium content to help students prepare for exams. Lipids are molecules that contain both hydrophobic and hydrophilic groups, making them amphipathic. In an aqueous solution, amphipathic lipids will orient themselves with their polar heads towards the water and nonpolar tails pointing away from the water, allowing them to form micelles and lipid bilayers that are important for processes like lipid digestion and formation of cell membranes.
The urinary system removes waste from the body via the kidneys, ureters, bladder, and urethra. The kidneys filter blood to form urine via nephrons, which consist of a renal corpuscle and renal tubule. Urine passes from nephrons to the renal pelvis and ureters into the bladder, then exits via the urethra. The kidneys also regulate electrolytes and blood pressure by producing hormones like erythropoietin and renin.
Examville.com is a website that provides online practice tests, live classes, tutoring, study guides, Q&A, and premium content to help students prepare for exams. The document then discusses various topics related to carbohydrate metabolism including glycogen metabolism, gluconeogenesis, glycolysis, and glycogen storage diseases. It provides details on the pathways and regulation of glucose synthesis and breakdown in the body.
The document discusses the diencephalon, which is a region of the brain situated between the cerebrum and brainstem. It consists of four main parts: the thalamus, hypothalamus, epithalamus, and subthalamus. The thalamus acts as a gateway to the cerebral cortex by integrating sensory information and influencing mood and emotions. The hypothalamus regulates vital functions such as body temperature, hunger, and circadian rhythms. Examville.com is an online learning site that offers practice tests, classes, tutoring, study guides, and premium content to help students prepare for exams.
2. Human Heart
HEART
is a squared
shape, muscular
organ responsible
for pumping blood
through the blood
vessels by
repeated, rhythmic
contractions, or a
similar structure in
annelids,
mollusks, and
arthropods
3. The Heart is divided into two
Right heart
Left heart
4. Right heart
is a term used to refer collectively to the right atrium and
right ventricle of the heart; occasionally, this term is intended to
reference the right atrium, right ventricle, and the pulmonary trunk
collectively.
The right atrium receives deoxygenated systemic blood from the
superior and inferior vena cavae. The blood is then pumped through
the tricuspid valve into the right ventricle, which in turn pumps the
blood through the pulmonary valve into the pulmonary artery.
Vena cavae, Coronary sinus
→ Right atrium (auricle, fossa ovalis, limbus of fossa
ovalis, crista terminalis, valve of the inferior vena cava,
valve of the coronary sinus)
Tricuspid valve
→ Right ventricle (conus arteriosus, moderator
band/septomarginal trabecula)
Pulmonary valve
→ Pulmonary Artery
→ Pulmonary Circulation
5. The superior and inferior vena
Venae cavae cava are collectively called the
venae cavae. They are the veins
that return de-oxygenated blood
from the body into the heart.
They both empty into the right
atrium.
The superior vena cava (or
anterior)
is above the heart, and
forms from a convergence of the
left and right brachiocephalic
veins that contain blood from
the head and the arms. The vena
cavae carry deoxygenated blood
from the body to the right atrium
of the heart.
The venae cavae is the largest
blood vessel in the heart.
The inferior vena cava (or
posterior vena cava)
travels up alongside the
abdominal aorta with blood from
the lower part of the body.
6. Coronary Sinus
Coronary Sinus is a collection of veins
joined together to form a large
vessel that collects blood from
the myocardium of the heart. It
is present in humans and other
animals.
Location
It is located between the left
atrium and ventricle on the
posterior surface of the heart.
It runs transversely in the
groove between the left atrium
and ventricle on the posterior
surface of the heart.
The coronary sinus orifice
(opening) is just superior to the
septal leaflet of the tricuspid
valve. The coronary sinus orifice
is also known as the ostium of
the coronary sinus
7. Right Atrium
Right Atrium (in older texts
termed the "right auricle")
is one of four chambers (two
atria and two ventricles) in the
human heart. It receives de-
oxygenated blood from the superior
and inferior vena cavae and the
coronary sinus, and pumps it into
the right ventricle through the
tricuspid valve.
Sinoatrial node (SAN)
is located within this chamber
next to the vena cava. This is a
group of pacemaker cells which
spontaneously depolarise to create
an Action Potential. The cardiac
action potential then spreads across
both atria causing them to contract
forcing the blood they hold into their
corresponding ventricles.
8. Right Ventricle
Right Auricular Appendix
Fossa Ovalis
Limbus of Fossa Ovalis
Crista Terminalis
Valve of the Inferior Vena Cava
Valve of the Coronary Sinus
9. Right Auricular Appendix
Right auricular appendix
(right auricula, right
auricle) is a small conical
muscular pouch attached
to the right atrium of the
heart. Its margins present
a dentated edge. It projects
from the upper and front
part of the sinus forward
and toward the left side,
overlapping the root of the
aorta.
10. Fossa Ovalis (heart)
Found in the right
atrium of the heart, the
Fossa Ovalis is an
embryonic remnant of
the foramen ovale,
which normally closes
shortly after birth.
Failure of the foramen
ovale to close results
in a disorder known as
patent foramen ovale.
11. Limbus of Fossa Ovalis
Limbus of fossa ovalis
(annulus ovalis)
is the prominent oval
margin of the fossa ovalis.
It is most distinct above
and at the sides of the fossa;
below, it is deficient.
A small slit-like valvular
opening is occasionally found,
at the upper margin of the fossa,
leading upward beneath the
limbus, into the left atrium; it is
the remains of the fetal aperture
between the two atria.
12. Crista Terminalis
In the development of
the human heart, the right
horn and transverse
portion of the sinus
venosus ultimately
become incorporated with
and form a part of the adult
right atrium, the line of
union between it and the
right auricle being
indicated in the interior of
the atrium by a vertical
crest, the crista terminalis
of His (Wilhelm His, Jr.).
13. Valve of the Inferior Vena Cava
The valve of the
inferior vena cava
(eustachian valve) serves
to direct the blood from
that vessel through the
foramen ovale into the left
atrium.
The eustachian valve
is the valve at the distal
end of the inferior vena
cava the passes blood
from the lower extremities
into the Right Atrium of the
heart
14. Valve of the Coronary Sinus
The valve of the
coronary sinus (Thebesian
valve) is a semicircular
fold of the lining
membrane of the atrium, at
the orifice of the coronary
sinus. The valve may vary
in size, or be completely
absent.
It may prevent the
regurgitation of blood into
the sinus during the
contraction of the atrium.
This valve may be
double or it may be
cribriform.
15. Tricuspid Valve
Tricuspid valve
is on the right side of
the heart, between the
right atrium and the right
ventricle. The normal
tricuspid valve usually has
three leaflets and three
papillary muscles.
16. Tricuspid Valve
The largest cusp is interposed between the
atrioventricular orifice and the conus arteriosus and is
termed the anterior or infundibular cusp.
A second, the posterior or marginal cusp, is in relation
to the right margin of the ventricle.
A third, the medial or septal cusp, to the ventricular
septum.
The tricuspid valve prevents the blood from returning
to the right atrium when the right ventricle contracts
***** The tricuspid valve also opens and
closes at periods of time making the blood
flow through from the right atrium to the
right ventricle*****
17. Right Ventricle
Conus Arteriosus
Moderator Band/Septomarginal
Trabecula
18. Right Ventricle
Right ventricle
is one of four chambers
(two atria and two
ventricles) in the human
heart. It receives de-
oxygenated blood from the
right atrium via the
tricuspid valve, and pumps
it into the pulmonary artery
via the pulmonary valve.
It is triangular in form,
and extends from the right
atrium to near the apex of
the heart.
19. Conus Arteriosus
Conus Arteriosus
is a conical pouch formed
from the upper and left angle of
the right ventricle, from which
the pulmonary artery arises.
A tendinous band, which
may be named the tendon of the
conus arteriosus, extends
upward from the right
atrioventricular fibrous ring and
connects the posterior surface
of the conus arteriosus to the
aorta. This is also called the
infundibulum, and it is the
entrance from the right ventricle
into the pulmonary artery and
pulmonary trunk. The wall of the
infundibulum is smooth.
20. Septomarginal trabecula
Septomarginal (or moderator band)
Trabecula is a muscular band of heart
tissue found in the right ventricle. It
is well-marked in sheep and some
other animals, and frequently
extends from the base of the
anterior papillary muscle to the
ventricular septum.
From its attachments it was
thought to prevent overdistension
of the ventricle, and was named the
"moderator band". However, more
recent research has indicated that it
is more properly considered part of
the electrical conduction system of
the heart, and in that capacity it is
called the "septomarginal
trabecula". The TA name is
"trabecula septomarginalis".
The moderator band is often
used by radiologists to more easily
identify the right ventricle in
prenatal ultrasound.
21. Pulmonary Valve
Pulmonary Valve
is the semilunar valve of the
heart that lies between the right
ventricle and the pulmonary artery
and has three cusps. Similar to the
aortic valve, the pulmonic valve
opens in ventricular systole, when
the pressure in the right ventricle
rises above the pressure in the
pulmonary artery. At the end of
ventricular systole, when the
pressure in the right ventricle falls
rapidly, the pressure in the
pulmonary artery will close the
pulmonic valve.
23. Pulmonary Artery
Pulmonary arteries carry
blood from the heart to the lungs.
They are the only arteries (other
than umbilical arteries in the
fetus) that carry deoxygenated
blood.
In the human heart, the
pulmonary trunk (pulmonary
artery or main pulmonary artery)
begins at the base of the right
ventricle. It is short and wide -
approximately 5 cm (2 inches) in
length and 3 cm (1.2 inches) in
diameter. It then branches into
two pulmonary arteries (left and
right), which deliver deoxygenated
blood to the corresponding lung.
24. Pulmonary Circulation
Pulmonary Circulation
is the portion of the cardiovascular system which carries oxygen-
depleted blood away from the heart, to the lungs, and returns oxygenated
blood back to the heart. The term is contrasted with systemic circulation.
Oxygen-depleted blood from the body leaves the right heart through the
pulmonary arteries, which carry it to the lungs, where red blood cells release
carbon dioxide and pick up oxygen during respiration. The oxygenated blood
then leaves the lungs through the pulmonary veins, which return it to the left
heart, completing the pulmonary cycle. The blood is then distributed to the
body through the systemic circulation before returning again to the
pulmonary circulation.
25. Left heart
is a term used to refer collectively to the left atrium and lef
ventricle of the heart; occasionally, this term is intended to reference
the left atrium, left ventricle, and the aorta collectively.
The left atrium receives oxygenated pulmonic blood from the
pulmonary veins. The blood is then pumped through the mitral valve
into the left ventricle, which in turn pumps the blood through the aortic
valve into the aorta.
The left side of the heart is thicker than the right because of the
requirement to pump blood from the left throughout the body, as
opposed to the right side pumping only through the lungs.
Pulmonary veins
Left atrium
Left Auricular Appendix
Mitral valve
Left ventricle
Aortic valve
Aortic sinus
Aorta
Systemic circulation
26. Pulmonary Veins
The pulmonary veins carry
oxygen-rich blood from the
lungs to the left atrium of the
heart. They are the only veins in
the post-fetal human body that
carry oxygenated (red) blood.
• The pulmonary veins return the
oxygenated blood from the
lungs to the left atrium of the
heart. They are four in number,
two from each lung, and are
destitute of valves. They are
• Right Inferior
• Right Superior
• Left Inferior
• Left Superior
27. Left Atrium
Left atrium
is one of the four chambers
in the human heart. It receives
oxygenated blood from the
pulmonary veins, and pumps it
into the left ventricle.
Blood is pumped through
the left atrioventricular orifice,
which contains the mitral valve.
A normal left atrium may be up
to 5.5cm in maximum diameter;
any larger than this is a sign of
cardiac failure. This may occur
in cases of mitral regurgitation.
28. Left Auricular Appendix
Left Auricular Appendix
(left auricula, left
auricle)
is a conical muscular
pouch connected to the left
atrium of the heart. It is
somewhat constricted at its
junction with the principal
cavity; it is longer, narrower,
and more curved than the right
auricular appendix, and its
margins are more deeply
indented.
It is directed forward and
toward the right and overlaps
the root of the pulmonary artery.
29. Mitral Valve
Mitral valve (also known
as the bicuspid valve or
left atrioventricular
valve)
is a dual flap (bi = 2) valve
in the heart that lies between the
left atrium (LA) and the left
ventricle (LV). In Latin, the term
mitral means shaped like a
miter, or bishop's cap. The
mitral valve and the tricuspid
valve are known collectively as
the atrioventricular valves
because they lie between the
atria and the ventricles of the
heart and control flow.
30. Left ventricle
The left ventricle is
one of four chambers
(two atria and two
ventricles) in the human
heart. It receives
oxygenated blood from
the left atrium via the
mitral valve, and pumps
it into the aorta via the
aortic valve.
The left ventricle is
longer and more conical
in shape than the right,
and on transverse
section its concavity
presents an oval or
nearly circular outline. It
forms a small part of the
sternocostal surface and
a considerable part of
the diaphragmatic
surface of the heart; it
also forms the apex of
the heart.
31. Aortic Valve
Aortic valve
is one of the valves of the
heart. It lies between the left
ventricle and the aorta.
Morphology
The aortic valve has three
cusps. These cusps are half
moon shaped hence also called
aortic semilunar valve. Each
cusp has a small swelling in the
center called the nodule.
Dilatation of the wall of the aorta
behind these cusps is called
aortic sinus. When the aortic
valve is open, the normal size of
the orifice is 3-4 cm² in adults.
32. Aortic Sinus
An aortic sinus is one of the anatomic dilations of the
ascending aorta, which occurs just above the aortic valve.
There are generally three aortic sinuses, the left, the right and the
posterior.
• The left aortic sinus gives rise to the left coronary artery.
• The right aortic sinus gives rise to the right coronary artery.
• Usually, no vessels arise from the posterior aortic sinus, which
is therefore known as the non-coronary sinus.
33. Aorta
The aorta (generally
pronounced [eɪˈɔːtə] or
"ay-orta") is the largest
artery in the human body,
originating from the left
ventricle of the heart and
bringing oxygenated blood
to all parts of the body in
the systemic circulation.
The course of the Aorta
The aorta is usually divided
into five
segments/sections:
• Ascending aorta
• Arch of aorta
• Descending aorta
• Thoracic aorta
• Abdominal aorta
34. Ascending aorta, Arch of aorta, Descending aorta
• Ascending Aorta —
the section between the
heart and the arch of aorta
• Arch of Aorta — the
peak part that looks
somewhat like an inverted
"U"
• Descending Aorta —
the section from the arch
of aorta to the point where
it divides into the common
iliac arteries
35. Thoracic aorta
Thoracic aorta
is contained in the
posterior mediastinal cavity.
It begins at the lower
border of the fourth thoracic
vertebra where it is
continuous with the aortic
arch, and ends in front of the
lower border of the twelfth at
the aortic hiatus in the
diaphragm.
At its commencement, it
is situated on the left of the
vertebral column; it
approaches the median line
as it descends; and, at its
termination, lies directly in
front of the column.
36. Abdominal Aorta
Abdominal Aorta
is a large artery in
the abdominal cavity.
As part of the aorta, it
is a direct continuation
of descending aorta
(of the thorax).
37. Systemic Circulation
Systemic Circulation
is the portion of the cardiovascular
system which carries oxygenated
blood away from the heart, to the body,
and returns deoxygenated blood back
to the heart. The term is contrasted
with pulmonary circulation.
Oxygenated blood from the lungs
leaves the left heart through the aorta,
from where it is distributed to the
body's organs and tissues, which
absorb the oxygen, through a complex
network of arteries, arterioles, and
capillaries. The deoxygenated blood is
then collected by venules, from where
it flows first into veins, and then into
the inferior and superior venae cavae,
which return it to the right heart,
completing the systemic cycle. The
blood is then re-oxygenated through
the pulmonary circulation before
returning again to the systemic
circulation.
38. Layers of the Heart
1.) Pericardium
1.1.)Sinus
a.) Oblique Sinus
b.) Transverse Sinus
2.) Epicardium
3.) Myocardium
4.) Endocardium
5.) Cardiac skeleton
5.1.) Fibrous trigone
5.2.) Fibrous rings
39. Pericardium
is a double-walled sac that contains the heart and the roots of the great
vessels.
Layers of Pericardium
A.) Fibrous Pericardium
is the most superficial layer. It is a dense connective tissue,
protecting the heart, anchoring it to the surrounding walls, and
preventing it from overfilling with blood. It is continuous with the outer
adventitial layer of the neighboring great blood vessels.
B.) Serous Pericardium
is deep to the fibrous pericardium. It contains two layers, both of
which function in lubricating the heart to prevent friction from
occurring during heart activity.
40. Pericardial Sinuses
The cul-de-sac enclosed between the limbs of the
inverted U of the venous mesocardium lies behind the left
atrium and is known as the Oblique Sinus.
The passage between the venous and arterial
mesocardia—i.e., between the aorta and pulmonary artery
in front and the atria behind—is termed the Transverse
Sinus.
41. Epicardium
describes the outer layer of heart tissue (from Greek; epi-
outer, cardium heart). When considered as a part of the
pericardium, it is the inner layer, or visceral pericardium.
Its largest constituent is connective tissue and functions as
a protective layer. The visceral pericardium apparently
produces the pericardial fluid, which lubricates motion between
the inner and outer layers of the pericardium.
During ventricular contraction, the wave of depolarization
moves from endocardial to epicardial surface.
42. Myocardium
is the muscular tissue of the heart.
Relationship to other layers
The other tissues of the heart are:
The Endocardium (inner lining, effectively a specialised endothelium)
The Epicardium (a connective tissue layer around the heart with a
serous surface. It may be considered as the inner (visceral) layer of the
pericardium).
Composition
The myocardium is composed of specialized cardiac muscle cells
with an ability not possessed by muscle tissue elsewhere in the body.
Cardiac muscle, like other muscles, can contract, but it can also
conduct electricity, like nerves.
The blood supply of the myocardium is by the coronary arteries.
43. Endocardiumlayer of tissue that lines
In the heart, the endocardium is the innermost
the chambers of the heart. Its cells, embryologically and biologically, are
similar to the endothelial cells that line blood vessels.
The endocardium overlies the much more voluminous myocardium, the
muscular tissue responsible for the contraction of the heart. The outer layer
of the heart is termed epicardium and the heart is surrounded by a small
amount of fluid enclosed by a fibrous sac called the pericardium.
Function
Recently, it has become evident that the endocardium, which is
primarily made up of endothelial cells, controls myocardial function. This
modulating role is separate from the homeometric and heterometric
regulatory mechanisms that control myocardial contractility. Moreover, the
endothelium of the myocardial (heart muscle) capillaries, which is also
closely appositioned to the cardiomyocytes (heart muscle cells) are involved
in this modulatory role. Thus, the cardiac endothelium (both the endocardial
endothelium and the endothelium of the myocardial capillaries) controls the
development of the heart in the embryo as well as in the adult, for example
during hypertrophy. Additionally, the contractility and electrophysiological
environment of the cardiomyocyte are regulated by the cardiac endothelium.
The endocardial endothelium may also act as a kind of blood-heart
barrier (analogous to the blood-brain barrier), thus controlling the ionic
composition of the extracellular fluid in which the cardiomyocytes bathe.
44. Cardiac skeleton
Cardiac skeleton (sometimes called "fibrous skeleton of the heart") refers to
the structure of dense connective tissue in the heart that separates the atria
from the ventricles.
It is not a "true" skeleton, but it does provide structure and support for
the heart, as well as isolating the electric charges that go through the heart.
The left atrioventricular ring is closely connected, by its right margin,
with the aortic arterial ring; between these and the right atrioventricular ring
is a triangular mass of fibrous tissue, the fibrous trigone, which represents
the os cordis seen in the heart of some of the larger animals, as the ox and
elephant.
The right and left fibrous rings of heart (anulus fibrosus cordis)
surround the atrioventricular and arterial orifices, and are stronger upon the
left than on the right side of the heart. The right fibrous ring is known as the
anulus fibrosus dexter cordis, and the left is known as the anulus fibrosus
sinister cordis
47. Musculi Pectinati
In the right atrium,
behind the crest the
internal surface of the
atrium is smooth, while in
front of it the muscular
fibers of the wall are
raised into parallel ridges
resembling the teeth of a
comb, and hence named
the musculi pectinati
(pectinate muscles).
49. Interventricular Septum
Portions
Interventricular septum (or
ventricular septum, or during
development septum inferius) is The greater portion of it is
the stout wall separating the lower thick and muscular and constitutes
chambers (the ventricles) of the the muscular ventricular septum.
heart from one another.
Its upper and posterior part,
The ventricular septum is which separates the aortic
directed obliquely backward and to vestibule from the lower part of the
the right, and is curved with the right atrium and upper part of the
convexity toward the right ventricle: right ventricle, is thin and fibrous,
its margins correspond with the and is termed the membranous
anterior and posterior longitudinal ventricular septum (septum
sulci. membranaceum).
50. Trabeculae Carneae
The trabeculae carneae (columnae carneae) are
rounded or irregular muscular columns which project from the
whole of the inner surface of the ventricle, with the exception of
the conus arteriosus.
They are of three kinds:
1.) Some are attached along their entire length on one side and merely
form prominent ridges,
2.) Others are fixed at their extremities but free in the middle,
3.) While a third set (musculi papillares) are continuous by their bases with
the wall of the ventricle, while their apices give origin to the chordæ
tendineæ which pass to be attached to the segments of the tricuspid valve.
51. Chordae Tendinae
The chordae
tendineae, or heart
strings, are cord-like
tendons that connect the
papillary muscles to the
tricuspid valve and the
mitral valve in the heart.
When the right
ventricle of the heart
contracts, the blood
pressure pushes the
tricuspid valve which closes
and prevents a backflow of
blood into the right atrium.
The chordae tendineae
prevents the flaps from
being everted into the right
atrium. Similarly, these
cord-like tendons hold in
position other flaps like the
bicuspid or mitral valve.
52. Papillary Muscle
Papillary muscles of
the heart serve to limit
the movements of the
mitral and tricuspid
valves. These muscles
contract to tighten the
chordae tendineae,
which in turn prevent
inversion. This occurs
in response to
pressure gradients.
Instead they brace the
valves against the high
pressure, preventing
regurgitation of
ventricular blood back
into the atrial cavities.
53. Heart Valves
Heart valves are
valves in the heart that
maintain the
unidirectional flow of
blood by opening and
closing depending on
the difference in
pressure on each side.
The mechanical
equivalent of the heart
valves would be the
reed valves.
54. Mitral Valve
The mitral valve
(also known as the
bicuspid valve or left
atrioventricular valve), is
a dual flap (bi = 2) valve in
the heart that lies between
the left atrium (LA) and the
left ventricle (LV). In Latin,
the term mitral means
shaped like a miter, or
bishop's cap. The mitral
valve and the tricuspid
valve are known
collectively as the
atrioventricular valves
because they lie between
the atria and the ventricles
of the heart and control
flow.
55. Tricuspid Valve
The tricuspid valve
is on the right side of the
heart, between the right
atrium and the right
ventricle. The normal
tricuspid valve usually has
three leaflets and three
papillary muscles.
Tricuspid valves may also
occur with two or four
leaflets, and the number
may change during life.
57. Aortic Valve
The aortic valve is one of the valves of the heart. It lies between the
left ventricle and the aorta.
Morphology
The aortic valve has three cusps. These cusps are half moon shaped
hence also called aortic semilunar valve. Each cusp has a small swelling in
the center called the nodule. Dilatation of the wall of the aorta behind these
cusps is called aortic sinus. When the aortic valve is open, the normal size of
the orifice is 3-4 cm² in adults.
Function & Physiology
During ventricular systole, pressure rises in the left ventricle. When the
pressure in the left ventricle rises above the pressure in the aorta, the aortic
valve opens, allowing blood to exit the left ventricle into the aorta. When
ventricular systole ends, pressure in the left ventricle rapidly drops. When
the pressure in the left ventricle decreases, the aortic pressure forces the
aortic valve to close. The closure of the aortic valve contributes the A2
component of the second heart sound (S2).
59. Pumonary Valve
is the semilunar valve of the heart that lies between the
right ventricle and the pulmonary artery and has three
cusps. Similar to the aortic valve, the pulmonic valve
opens in ventricular systole, when the pressure in the right
ventricle rises above the pressure in the pulmonary artery.
At the end of ventricular systole, when the pressure in the
right ventricle falls rapidly, the pressure in the pulmonary
artery will close the pulmonic valve.
The closure of the pulmonic valve contributes the P2
component of the second heart sound (S2). The right heart
is a low-pressure system, so the P2 component of the
second heart sound is usually softer than the A2
component of the second heart sound. However, it is
physiologically normal in some young people to hear both
components separated during inhalation.
60. Regions of The Heart
1.) Base
2.) Apex
3.) Grooves
a.) Coronary/atrioventricular
b.) Interatrial
c.) Anterior interventricula
d.) Posterior interventricular
4.) Surfaces
a.) Sternocostal
b.) Diaphragmatic
5.) Borders
a.) Right
b.) Left
61. Base of the Heart
Base of the heart, directed upward, backward,
and to the right, is separated from the fifth,
sixth, seventh, and eighth thoracic vertebræ by
the esophagus, aorta, and thoracic duct.
It is formed mainly by the left atrium, and,
to a small extent, by the back part of the right
atrium.
Somewhat quadrilateral in form, it is in
relation above with the bifurcation of the
pulmonary artery, and is bounded below by
the posterior part of the coronary sulcus,
containing the coronary sinus.
On the right it is limited by the sulcus
terminalis of the right atrium, and on the left by
the ligament of the left vena cava and the
oblique vein of the left atrium.
The four pulmonary veins, two on either
side, open into the left atrium, while the
superior vena cava opens into the upper, and
the anterior vena cava into the lower, part of
the right atrium.
62. Apex of the Heart
Apex of the heart
is the lowest superficial part of
the heart.
It is directed downward, forward,
and to the left, and is overlapped by
the left lung and pleura.
External Anatomy
It lies behind the fifth left
intercostal space, 8 to 9 cm. from the
mid-sternal line, slightly medial to the
midclavicular line.
Alternately, it can be found about
4 cm. below and 2 mm. to the medial
side of the left mammary papilla.
It's function is to pump blood to
left atruim
64. Coronary Sulcus
The atria of the heart are separated from
the ventricles by the coronary sulcus
(coronary groove, auriculoventricular
groove, atrioventricular groove); this
contains the trunks of the nutrient vessels
of the heart, and is deficient in front, where
it is crossed by the root of the pulmonary
artery.
65. Interatrial Groove
Interatrial groove, separating the two
atria, is scarcely marked on the
posterior surface, while anteriorly it is
hidden by the pulmonary artery and
aorta.
66. Anterior Interventricular Sulcus
The ventricles of the heart are separated
by two grooves, one of which, the anterior
longitudinal sulcus (or anterior
interventricular sulcus), is situated on the
sternocostal surface of the heart, close to its
left margin. The other groove separating the
ventricles is the posterior interventricular
sulcus.
67. Posterior Interventricular Sulcus
The ventricles are separated by two grooves,
one of which, the anterior longitudinal sulcus, is
situated on the sternocostal surface of the heart,
close to its left margin, the other posterior
longitudinal sulcus (posterior interventricular
sulcus, inferior interventricular groove), on the
diaphragmatic surface near the right margin.
In it run the posterior interventricular artery
and middle cardiac vein.
69. Sternocostal Surface of Heart
The sternocostal surface of the heart (anterior
surface of the heart) is directed forward, upward,
and to the left.
Its lower part is convex, formed chiefly by the
right ventricle, and traversed near its left margin
by the anterior longitudinal sulcus.
Its upper part is separated from the lower by
the coronary sulcus, and is formed by the atria; it
presents a deep concavity, occupied by the
ascending aorta and the pulmonary artery.
70. Diaphragmatic Surface of Heart
The diaphragmatic surface of the heart,
directed downward and slightly backward, is
formed by the ventricles, and rests upon the
central tendon and a small part of the left
muscular portion of the diaphragm.
It is separated from the base by the
posterior part of the coronary sulcus, and is
traversed obliquely by the posterior
longitudinal sulcus.
72. Right Border of Heart
Right margin of the heart (right border of
heart)
is long, and is formed by the right atrium above and the
right ventricle below.
The atrial portion is rounded and almost vertical; it is
situated behind the third, fourth, and fifth right costal
cartilages about 1.25 cm. from the margin of the sternum.
The ventricular portion, thin and sharp, is named the
acute margin; it is nearly horizontal, and extends from the
sternal end of the sixth right coastal cartilage to the apex
of the heart.
73. Left Margin of Heart
The left margin of heart (or obtuse margin) is shorter
than the right border of heart, full, and rounded: it
is formed mainly by the left ventricle, but to a
slight extent, above, by the left atrium.
It extends from a point in the second left
intercostal space, about 2.5 mm. from the sternal
margin, obliquely downward, with a convexity to
the left, to the apex of the heart.
74. Electrical conduction system of
the heart
The normal electrical conduction in the heart allows the
impulse that is generated by the sinoatrial node (SA node)
of the heart to be propagated to (and stimulate) the
myocardium (Cardiac muscle). After myocardium is
stimulated, it contracts. It is the ordered stimulation of the
myocardium that allows efficient contraction of the heart,
thereby allowing blood to be pumped throughout the body.
Cardiac Pacemaker
SA node
AV node
Bundle of His
Purkinje Fibers
75. Cardiac Pacemaker
The contractions of the heart are controlled by
chemical impulses, which fire at a rate which controls the
beat of the heart.
The cells that create these rhythmical impulses are
called pacemaker cells, and they directly control the heart
rate. Artificial devices also called pacemakers can be
used after damage to the body's intrinsic conduction
system to produce these impulses synthetically.
76. Sinoatrial node
Sinoatrial node (abbreviated SA node or
SAN, also called the sinus node)
is the impulse generating (pacemaker) tissue
located in the right atrium of the heart. It is a group
of cells positioned on the wall of the right atrium,
near the entrance of the superior vena cava. These
cells are modified cardiac myocytes. They possess
some contractile filaments, though they do not
contract.
77. Atrioventricular node
Atrioventricular node (abbreviated AV
node)
is an area of specialized tissue between the atria
and the ventricles of the heart, which conducts the
normal electrical impulse from the atria to the
ventricles. The AV node is also known as the
Aschoff-Tawara node.
The AV node receives two inputs from the atria:
posteriorly via the crista terminalis, and anteriorly
via the interatrial septum.
An important property that is unique to the AV
node is decremental conduction. This is the property
of the AV node that prevents rapid conduction to the
ventricle in cases of rapid atrial rhythms, such as
atrial fibrillation or atrial flutter.
78. Bundle of His
Bundle of His
is a collection of heart
muscle cells specialized for
electrical conduction that
transmits the electrical impulses
from the AV node (located
between the atria and the
ventricles) to the point of the
apex of the fascicular branches.
The fascicular branches then
lead to the Purkinje fibers which
innervate the ventricles, causing
the cardiac muscle of the
ventricles to contract at a paced
interval. These specialized
muscle fibres in the heart were
named after the Swiss
cardiologist Wilhelm His, Jr.,
who discovered them in 1893.
79. Purkinje Fibers
Purkinje fibers (or Purkyne tissue) are located in the
inner ventricular walls of the heart, just beneath the
endocardium. These fibers are specialized myocardial
fibers that conduct an electrical stimulus or impulse that
enables the heart to contract in a coordinated fashion.
Function
Purkinje fibers work with the sinoatrial node (SA node)
and the atrioventricular node (AV node) to control the heart
rate.
During the ventricular contraction portion of the
cardiac cycle, the Purkinje fibers carry the contraction
impulse from the left and right bundle branches to the
myocardium of the ventricles. This causes the muscle
tissue of the ventricles to contract and force blood out of
the heart — either to the pulmonary circulation (from the
right ventricle) or to the systemic circulation (from the left
ventricle).