The document summarizes the arterial pulse, venous pulse, circulation time, and the triple response of Lewis. It describes where arterial and venous pulses can be measured, factors that influence circulation time, and provides details on the triple response of Lewis - an initial red line followed by a flare and wheal caused by the release of histamine from mast cells. Normal pulse rates are also outlined for different age groups.
This document discusses the regulation of blood pressure on short, intermediate, and long term timescales.
Short term regulation occurs over seconds to minutes and involves baroreceptors, chemoreceptors, and the central nervous system ischemic response. Intermediate regulation over minutes to hours is mediated by capillary fluid shifts and stress relaxation in blood vessels. Long term regulation over days to years involves the renal body fluid mechanism and renin-angiotensin system to control extracellular fluid levels and blood pressure.
This document discusses the neuro-muscular junction, including its structure, function, and related disorders. It begins by outlining the objectives of describing the junction's schematic diagram, transmission events, neuromuscular blockers and their mechanisms, and common disorders. It then provides details on the presynaptic and postsynaptic portions, the synaptic cleft, acetylcholine receptors, and the steps of neuromuscular transmission. Examples are given of neuromuscular blockers like curare and their mechanisms of action. Disorders covered include myasthenia gravis and Lambert-Eaton syndrome.
it contains all the physiology of lung volume and capacity.
in this we study:-
introduction
lung volume
lung capacities
measurements of lung volume and capacities.
measurement of FRC and RV.
vital capacity.
FEV
RMV
MBC
PEFR
restrictive and obstructive respiratory disease.
DETERMINANTS AND FACTORS AFFECTING CARDIAC OUTPUTakash chauhan
This document discusses the determinants and factors affecting cardiac output. It defines cardiac output as the volume of blood pumped by the heart each minute, which is determined by stroke volume and heart rate. Ejection fraction is explained as the fraction of blood ejected from the ventricles with each heartbeat. Cardiac output can vary due to physiological factors like age, sex, exercise, and pathological factors like fever or shock. Cardiac output is maintained by four main factors - venous return, force of contraction, heart rate, and peripheral resistance. Venous return depends on respiratory pumping, muscle pumping, gravity, and venous pressure.
The document summarizes the mechanism of skeletal muscle contraction. It describes how an action potential leads to a rise in intracellular calcium levels through excitation-contraction coupling. This triggers the sliding filament theory where actin and myosin filaments slide past each other through cross-bridge cycling powered by ATP hydrolysis. Calcium binds to troponin C, allowing the power stroke to occur as myosin heads pull the actin filaments towards the center of the sarcomere. Relaxation occurs as calcium is re-sequestered in the sarcoplasmic reticulum, breaking the cross-bridges.
The document discusses capillary circulation and microcirculation. It covers the structure of capillaries including their thin endothelial cell walls allowing for exchange of nutrients, wastes, and fluid. It describes the Starling forces that govern fluid filtration and exchange between blood and tissues, including capillary pressure, plasma and interstitial fluid oncotic pressures, and other factors. It also discusses edema, the accumulation of excess fluid in tissues, which can occur intracellularly or extracellularly due to various causes that impact capillary permeability or lymph flow.
This document describes the four main heart sounds and how to auscultate them using a stethoscope. It explains that the first heart sound corresponds to closure of the atrioventricular valves and the R wave of an ECG. The second heart sound corresponds to closure of the semilunar valves and the T wave of an ECG. The third heart sound occurs during rapid ventricular filling between the T and P waves. The fourth heart sound corresponds to atrial contraction between the P and Q waves. It identifies the best areas over the heart to auscultate each sound using a stethoscope.
Cardiac muscle cells have characteristics that allow the heart to contract rhythmically and conduct electrical impulses throughout. Key properties include automaticity which allows the cells to spontaneously depolarize without external stimulation, rhythmicity which enables contraction at regular intervals, excitability to respond to electrical signals, and conductivity to propagate the signals. The refractory period after contraction is longer for cardiac muscle than skeletal muscle. Electrical conduction is faster through specialized fibers but slower in nodal pathways due to fewer connections between cells.
This document discusses the regulation of blood pressure on short, intermediate, and long term timescales.
Short term regulation occurs over seconds to minutes and involves baroreceptors, chemoreceptors, and the central nervous system ischemic response. Intermediate regulation over minutes to hours is mediated by capillary fluid shifts and stress relaxation in blood vessels. Long term regulation over days to years involves the renal body fluid mechanism and renin-angiotensin system to control extracellular fluid levels and blood pressure.
This document discusses the neuro-muscular junction, including its structure, function, and related disorders. It begins by outlining the objectives of describing the junction's schematic diagram, transmission events, neuromuscular blockers and their mechanisms, and common disorders. It then provides details on the presynaptic and postsynaptic portions, the synaptic cleft, acetylcholine receptors, and the steps of neuromuscular transmission. Examples are given of neuromuscular blockers like curare and their mechanisms of action. Disorders covered include myasthenia gravis and Lambert-Eaton syndrome.
it contains all the physiology of lung volume and capacity.
in this we study:-
introduction
lung volume
lung capacities
measurements of lung volume and capacities.
measurement of FRC and RV.
vital capacity.
FEV
RMV
MBC
PEFR
restrictive and obstructive respiratory disease.
DETERMINANTS AND FACTORS AFFECTING CARDIAC OUTPUTakash chauhan
This document discusses the determinants and factors affecting cardiac output. It defines cardiac output as the volume of blood pumped by the heart each minute, which is determined by stroke volume and heart rate. Ejection fraction is explained as the fraction of blood ejected from the ventricles with each heartbeat. Cardiac output can vary due to physiological factors like age, sex, exercise, and pathological factors like fever or shock. Cardiac output is maintained by four main factors - venous return, force of contraction, heart rate, and peripheral resistance. Venous return depends on respiratory pumping, muscle pumping, gravity, and venous pressure.
The document summarizes the mechanism of skeletal muscle contraction. It describes how an action potential leads to a rise in intracellular calcium levels through excitation-contraction coupling. This triggers the sliding filament theory where actin and myosin filaments slide past each other through cross-bridge cycling powered by ATP hydrolysis. Calcium binds to troponin C, allowing the power stroke to occur as myosin heads pull the actin filaments towards the center of the sarcomere. Relaxation occurs as calcium is re-sequestered in the sarcoplasmic reticulum, breaking the cross-bridges.
The document discusses capillary circulation and microcirculation. It covers the structure of capillaries including their thin endothelial cell walls allowing for exchange of nutrients, wastes, and fluid. It describes the Starling forces that govern fluid filtration and exchange between blood and tissues, including capillary pressure, plasma and interstitial fluid oncotic pressures, and other factors. It also discusses edema, the accumulation of excess fluid in tissues, which can occur intracellularly or extracellularly due to various causes that impact capillary permeability or lymph flow.
This document describes the four main heart sounds and how to auscultate them using a stethoscope. It explains that the first heart sound corresponds to closure of the atrioventricular valves and the R wave of an ECG. The second heart sound corresponds to closure of the semilunar valves and the T wave of an ECG. The third heart sound occurs during rapid ventricular filling between the T and P waves. The fourth heart sound corresponds to atrial contraction between the P and Q waves. It identifies the best areas over the heart to auscultate each sound using a stethoscope.
Cardiac muscle cells have characteristics that allow the heart to contract rhythmically and conduct electrical impulses throughout. Key properties include automaticity which allows the cells to spontaneously depolarize without external stimulation, rhythmicity which enables contraction at regular intervals, excitability to respond to electrical signals, and conductivity to propagate the signals. The refractory period after contraction is longer for cardiac muscle than skeletal muscle. Electrical conduction is faster through specialized fibers but slower in nodal pathways due to fewer connections between cells.
The document summarizes gastric motility and secretion. It discusses the main functions of the stomach including storage, preparing chyme, and absorption. It describes the different cell types in the stomach that secrete gastric juice components like HCl and pepsinogen. It also outlines the roles of gastric motility in serving as a reservoir, breaking down food, and emptying contents at a controlled rate. Key regulators of gastric emptying and secretion include hormones like CCK, gastrin, and secretin.
The document discusses the movements of the small and large intestines. It begins by describing two types of movements in the small intestine - mixing (segmentation) contractions and propulsive (peristalsis) movements. Nervous and hormonal factors that control peristalsis are discussed, including gastroenteric reflexes and hormones like gastrin and CCK. The document then covers the ileocecal valve and sphincter, which prevent backflow and allow controlled emptying. Finally, it describes two types of movements in the large intestine - mixing (haustration) movements proximally and propulsive (mass) movements distally.
Baroreceptors And Negative Feedback MechanismSulav Shrestha
Baroreceptors are mechanoreceptors located in the carotid arteries and aorta that detect changes in blood pressure. As part of a negative feedback system called the baroreflex, baroreceptors send signals to the brain to increase or decrease heart rate and vascular resistance to maintain normal blood pressure. When blood pressure rises, baroreceptors inhibit the vasomotor center of the brain to decrease sympathetic nervous system activity and lower blood pressure. Conversely, lower blood pressure activates the vasomotor center to increase sympathetic activity and raise blood pressure. In addition to short term regulation, baroreceptors can reset over days to the new blood pressure level in cases of chronic high blood pressure.
There are three main mechanisms that control arterial blood pressure:
1. Rapid mechanisms act within seconds to minutes through baroreceptor and chemoreceptor reflexes in the medulla to increase or decrease heart rate, cardiac contractility, and peripheral resistance.
2. Intermediate mechanisms act over hours to days through stress relaxation of blood vessels and capillary fluid shifts to regulate blood volume and pressure.
3. Long-term mechanisms act over days to weeks through regulation of extracellular fluid volume by atrial natriuretic peptide, ADH, and the renin-angiotensin system to control blood pressure by altering sodium and water reabsorption in the kidneys.
This document discusses gastric secretion and the physiology of stomach acid production. It covers the following key points:
1. The stomach lining contains various cell types that secrete substances like mucus, hydrochloric acid, and the enzyme pepsin. Parietal cells secrete hydrochloric acid through a mechanism involving hydrogen-potassium ATPase pumps.
2. Gastric acid secretion is regulated through neural and hormonal mechanisms in three phases: cephalic, gastric, and intestinal. The cephalic phase begins with eating cues, while the gastric phase responds to food in the stomach through gastrin and vagal stimulation.
3. Experiments like Pavlov's pouch and sham feeding helped
Dr. Nilesh Kate's document provides an overview of smooth muscle physiology. It discusses the functional anatomy and organization of smooth muscle, including that it is non-striated, involuntary muscle that exists in bundles. It describes the two types of smooth muscle - single unit and multi unit - and their characteristics. The document outlines the structure of smooth muscle fibers and covers the processes of excitability, contraction, and relaxation. It explains excitation and inhibition of smooth muscle can occur through nerves, hormones, pacemakers, stretching or temperature changes. In summary, the document provides a comprehensive review of smooth muscle types, organization, function and physiology.
The document discusses the defecation reflexes in humans. There are two main reflexes - the intrinsic defecation reflex mediated by the enteric nervous system and the parasympathetic defecation reflex mediated by the autonomic nervous system. When feces enter the rectum, stretch receptors in the rectal wall are stimulated which initiate peristaltic waves to move feces towards the rectum and relax the internal anal sphincter through these reflex pathways. Voluntary control of the external anal sphincter allows defecation to occur at convenient times through maneuvers like the Valsalva maneuver.
The neuromuscular junction consists of the motor neuron axon terminal, synaptic cleft, and motor end plate of muscle fiber. Acetylcholine is synthesized in the neuron, stored in vesicles, and released into the synaptic cleft upon arrival of an action potential. It binds nicotinic receptors on the muscle, opening ion channels and initiating an endplate potential that spreads and causes muscle contraction. Acetylcholine is then broken down by acetylcholinesterase to terminate its effect. Nondepolarizing muscle relaxants block transmission by preventing acetylcholine binding, while depolarizing relaxants directly activate ion channels. Anesthetic drugs can also impact transmission through desensitization or channel blockade effects.
This document summarizes the neuromuscular transmission process, including the structure and function of the neuromuscular junction, the role of acetylcholine, and the effects of various drugs. It describes how motor neurons innervate muscle fibers to form motor units. Transmission involves the release of acetylcholine from the motor neuron terminal, which binds nicotinic receptors and opens ion channels on the muscle fiber membrane. Various toxins and conditions like myasthenia gravis and Lambert-Eaton syndrome can disrupt this process.
This document discusses the concepts of blood pressure including systolic, diastolic, and mean arterial pressure. It defines normal blood pressure ranges and factors that can influence blood pressure such as age, sex, body size, emotions, exercise, meals, sleep, and gravity. The relationship between cardiac output, total peripheral resistance, and blood pressure is explained. Mechanisms for short-term blood pressure regulation including baroreceptor reflex, chemoreceptor reflex, and central nervous system ischemic response are outlined. Long-term regulation involves the kidneys, renin-angiotensin system, and pressure natriuresis.
This document discusses gastrointestinal motility and the movements of the small and large intestines. It describes the different types of movements that mix and propel food through the intestines, including segmental contractions, peristaltic contractions, and migrating motor complexes. These movements are controlled by pacemaker cells and nerves. The document also covers motility reflexes, large intestine movements like haustral shuttling and mass movements, and the defecation reflex. Motility allows for digestion, absorption of nutrients, and excretion of waste from the body.
The document discusses countercurrent exchange systems in various organs and tissues of the body including the kidney. It describes how the countercurrent multiplier system in the loop of Henle establishes a gradient that is maintained by the countercurrent exchanger system of the vasa recta, allowing the kidney to produce concentrated urine through the medullary countercurrent system. It also discusses how diuretics work by targeting different sites along the nephron to increase urine output.
The document summarizes the juxtaglomerular apparatus (JGA) and tubuloglomerular feedback mechanism. The JGA is located near the glomerulus and is formed by macula densa cells, extraglomerular mesangial cells, and juxtaglomerular cells. The primary function of the JGA is secretion of hormones like renin and prostaglandins. The tubuloglomerular feedback mechanism regulates glomerular filtration rate through detection of NaCl concentration by the macula densa cells, which signals the release of adenosine to constrict or dilate the afferent arteriole accordingly.
The document summarizes key aspects of respiratory physiology, including the four main functions of respiration, the mechanisms of pulmonary ventilation, gas exchange, and regulation of breathing. It describes the respiratory cycle of inspiration and expiration, how pressure gradients are established via changes in thoracic cavity size, and the roles of muscles like the diaphragm and intercostals. Pressure and volume changes during inhalation and exhalation are provided. Pulmonary volumes and capacities are defined, including vital capacity and functional residual capacity. Disorders like COPD and pulmonary fibrosis are also mentioned.
Skeletal muscle has electrical and mechanical properties. Electrically, it is excitable and conductive, allowing it to receive and propagate action potentials. Mechanically, it can contract when stimulated, shortenening and developing tension. Skeletal muscle action potentials last 2-4 ms and propagate at 3-5 m/s. Contraction occurs slightly after the electrical response and can be isometric (no shortening) or isotonic (shortening against a load). Force of contraction depends on factors like stimulus strength, frequency, initial muscle length, and temperature.
The document discusses the micturition reflex, which is the reflex by which the urinary bladder empties when full. It describes the physiological anatomy of the bladder, its innervation by sympathetic and parasympathetic nerves, and the normal pathway of the reflex from bladder filling to emptying. It also discusses some abnormalities in micturition that can occur due to deafferentation, denervation, or lesions disrupting control by higher brain centers.
This document discusses the neural regulation of respiration. It begins by outlining the respiratory centers located in the brainstem, including the dorsal respiratory group, ventral respiratory group, pneumotaxic center, and apneustic center. These centers generate the rhythmic pattern of breathing and control the rate and depth of respiration. The document then describes various inputs that affect the respiratory centers, including peripheral chemoreceptors, lung stretch receptors, and irritant receptors. It concludes by explaining how disrupting different parts of the respiratory control system, such as through brainstem transections or anesthesia overdose, can impact breathing patterns and potentially cause respiratory arrest.
Cardiac output refers to the volume of blood pumped by each ventricle per minute. It is determined by stroke volume, heart rate, preload, afterload, and peripheral resistance. Normal cardiac output is approximately 5 liters per minute. It can increase up to 600% in athletes due to enhanced cardiac reserve. Factors such as venous return, force of contraction, heart rate, and peripheral resistance maintain cardiac output within the body.
This document provides information on the structure and function of the kidney and renal circulation. It discusses the basic anatomy of the nephron and its parts including the glomerulus, proximal convoluted tubule, loop of Henle, distal convoluted tubule and collecting duct. It also describes the juxtaglomerular apparatus and its role in regulating blood pressure via the renin-angiotensin system. Regarding renal circulation, it notes the kidney receives a high blood flow and has a unique portal system, as well as features like autoregulation and high oxygen consumption.
this presentation comprises of everything about the process of defecation and the defecation reflex and the nerve supply involved.
also discusses about the types of defecation reflexes and deals about them seperately in detail.
This presentation is about normal wave patterns of JVP and their variations. It includes definition, mechanism, abnormalities and clinical significance of jugular venous pressure.
The arterial pulse is caused by the transmission of pressure waves along the arteries during ventricular systole. The pulse can be felt over arteries and provides information about heart rate, rhythm, and volume. The jugular venous pulse reflects right atrial pressure and is assessed by observing waves corresponding to atrial contraction and filling. Together, examining the arterial and jugular pulses provides clinical information about cardiovascular function and hemodynamics.
The document summarizes gastric motility and secretion. It discusses the main functions of the stomach including storage, preparing chyme, and absorption. It describes the different cell types in the stomach that secrete gastric juice components like HCl and pepsinogen. It also outlines the roles of gastric motility in serving as a reservoir, breaking down food, and emptying contents at a controlled rate. Key regulators of gastric emptying and secretion include hormones like CCK, gastrin, and secretin.
The document discusses the movements of the small and large intestines. It begins by describing two types of movements in the small intestine - mixing (segmentation) contractions and propulsive (peristalsis) movements. Nervous and hormonal factors that control peristalsis are discussed, including gastroenteric reflexes and hormones like gastrin and CCK. The document then covers the ileocecal valve and sphincter, which prevent backflow and allow controlled emptying. Finally, it describes two types of movements in the large intestine - mixing (haustration) movements proximally and propulsive (mass) movements distally.
Baroreceptors And Negative Feedback MechanismSulav Shrestha
Baroreceptors are mechanoreceptors located in the carotid arteries and aorta that detect changes in blood pressure. As part of a negative feedback system called the baroreflex, baroreceptors send signals to the brain to increase or decrease heart rate and vascular resistance to maintain normal blood pressure. When blood pressure rises, baroreceptors inhibit the vasomotor center of the brain to decrease sympathetic nervous system activity and lower blood pressure. Conversely, lower blood pressure activates the vasomotor center to increase sympathetic activity and raise blood pressure. In addition to short term regulation, baroreceptors can reset over days to the new blood pressure level in cases of chronic high blood pressure.
There are three main mechanisms that control arterial blood pressure:
1. Rapid mechanisms act within seconds to minutes through baroreceptor and chemoreceptor reflexes in the medulla to increase or decrease heart rate, cardiac contractility, and peripheral resistance.
2. Intermediate mechanisms act over hours to days through stress relaxation of blood vessels and capillary fluid shifts to regulate blood volume and pressure.
3. Long-term mechanisms act over days to weeks through regulation of extracellular fluid volume by atrial natriuretic peptide, ADH, and the renin-angiotensin system to control blood pressure by altering sodium and water reabsorption in the kidneys.
This document discusses gastric secretion and the physiology of stomach acid production. It covers the following key points:
1. The stomach lining contains various cell types that secrete substances like mucus, hydrochloric acid, and the enzyme pepsin. Parietal cells secrete hydrochloric acid through a mechanism involving hydrogen-potassium ATPase pumps.
2. Gastric acid secretion is regulated through neural and hormonal mechanisms in three phases: cephalic, gastric, and intestinal. The cephalic phase begins with eating cues, while the gastric phase responds to food in the stomach through gastrin and vagal stimulation.
3. Experiments like Pavlov's pouch and sham feeding helped
Dr. Nilesh Kate's document provides an overview of smooth muscle physiology. It discusses the functional anatomy and organization of smooth muscle, including that it is non-striated, involuntary muscle that exists in bundles. It describes the two types of smooth muscle - single unit and multi unit - and their characteristics. The document outlines the structure of smooth muscle fibers and covers the processes of excitability, contraction, and relaxation. It explains excitation and inhibition of smooth muscle can occur through nerves, hormones, pacemakers, stretching or temperature changes. In summary, the document provides a comprehensive review of smooth muscle types, organization, function and physiology.
The document discusses the defecation reflexes in humans. There are two main reflexes - the intrinsic defecation reflex mediated by the enteric nervous system and the parasympathetic defecation reflex mediated by the autonomic nervous system. When feces enter the rectum, stretch receptors in the rectal wall are stimulated which initiate peristaltic waves to move feces towards the rectum and relax the internal anal sphincter through these reflex pathways. Voluntary control of the external anal sphincter allows defecation to occur at convenient times through maneuvers like the Valsalva maneuver.
The neuromuscular junction consists of the motor neuron axon terminal, synaptic cleft, and motor end plate of muscle fiber. Acetylcholine is synthesized in the neuron, stored in vesicles, and released into the synaptic cleft upon arrival of an action potential. It binds nicotinic receptors on the muscle, opening ion channels and initiating an endplate potential that spreads and causes muscle contraction. Acetylcholine is then broken down by acetylcholinesterase to terminate its effect. Nondepolarizing muscle relaxants block transmission by preventing acetylcholine binding, while depolarizing relaxants directly activate ion channels. Anesthetic drugs can also impact transmission through desensitization or channel blockade effects.
This document summarizes the neuromuscular transmission process, including the structure and function of the neuromuscular junction, the role of acetylcholine, and the effects of various drugs. It describes how motor neurons innervate muscle fibers to form motor units. Transmission involves the release of acetylcholine from the motor neuron terminal, which binds nicotinic receptors and opens ion channels on the muscle fiber membrane. Various toxins and conditions like myasthenia gravis and Lambert-Eaton syndrome can disrupt this process.
This document discusses the concepts of blood pressure including systolic, diastolic, and mean arterial pressure. It defines normal blood pressure ranges and factors that can influence blood pressure such as age, sex, body size, emotions, exercise, meals, sleep, and gravity. The relationship between cardiac output, total peripheral resistance, and blood pressure is explained. Mechanisms for short-term blood pressure regulation including baroreceptor reflex, chemoreceptor reflex, and central nervous system ischemic response are outlined. Long-term regulation involves the kidneys, renin-angiotensin system, and pressure natriuresis.
This document discusses gastrointestinal motility and the movements of the small and large intestines. It describes the different types of movements that mix and propel food through the intestines, including segmental contractions, peristaltic contractions, and migrating motor complexes. These movements are controlled by pacemaker cells and nerves. The document also covers motility reflexes, large intestine movements like haustral shuttling and mass movements, and the defecation reflex. Motility allows for digestion, absorption of nutrients, and excretion of waste from the body.
The document discusses countercurrent exchange systems in various organs and tissues of the body including the kidney. It describes how the countercurrent multiplier system in the loop of Henle establishes a gradient that is maintained by the countercurrent exchanger system of the vasa recta, allowing the kidney to produce concentrated urine through the medullary countercurrent system. It also discusses how diuretics work by targeting different sites along the nephron to increase urine output.
The document summarizes the juxtaglomerular apparatus (JGA) and tubuloglomerular feedback mechanism. The JGA is located near the glomerulus and is formed by macula densa cells, extraglomerular mesangial cells, and juxtaglomerular cells. The primary function of the JGA is secretion of hormones like renin and prostaglandins. The tubuloglomerular feedback mechanism regulates glomerular filtration rate through detection of NaCl concentration by the macula densa cells, which signals the release of adenosine to constrict or dilate the afferent arteriole accordingly.
The document summarizes key aspects of respiratory physiology, including the four main functions of respiration, the mechanisms of pulmonary ventilation, gas exchange, and regulation of breathing. It describes the respiratory cycle of inspiration and expiration, how pressure gradients are established via changes in thoracic cavity size, and the roles of muscles like the diaphragm and intercostals. Pressure and volume changes during inhalation and exhalation are provided. Pulmonary volumes and capacities are defined, including vital capacity and functional residual capacity. Disorders like COPD and pulmonary fibrosis are also mentioned.
Skeletal muscle has electrical and mechanical properties. Electrically, it is excitable and conductive, allowing it to receive and propagate action potentials. Mechanically, it can contract when stimulated, shortenening and developing tension. Skeletal muscle action potentials last 2-4 ms and propagate at 3-5 m/s. Contraction occurs slightly after the electrical response and can be isometric (no shortening) or isotonic (shortening against a load). Force of contraction depends on factors like stimulus strength, frequency, initial muscle length, and temperature.
The document discusses the micturition reflex, which is the reflex by which the urinary bladder empties when full. It describes the physiological anatomy of the bladder, its innervation by sympathetic and parasympathetic nerves, and the normal pathway of the reflex from bladder filling to emptying. It also discusses some abnormalities in micturition that can occur due to deafferentation, denervation, or lesions disrupting control by higher brain centers.
This document discusses the neural regulation of respiration. It begins by outlining the respiratory centers located in the brainstem, including the dorsal respiratory group, ventral respiratory group, pneumotaxic center, and apneustic center. These centers generate the rhythmic pattern of breathing and control the rate and depth of respiration. The document then describes various inputs that affect the respiratory centers, including peripheral chemoreceptors, lung stretch receptors, and irritant receptors. It concludes by explaining how disrupting different parts of the respiratory control system, such as through brainstem transections or anesthesia overdose, can impact breathing patterns and potentially cause respiratory arrest.
Cardiac output refers to the volume of blood pumped by each ventricle per minute. It is determined by stroke volume, heart rate, preload, afterload, and peripheral resistance. Normal cardiac output is approximately 5 liters per minute. It can increase up to 600% in athletes due to enhanced cardiac reserve. Factors such as venous return, force of contraction, heart rate, and peripheral resistance maintain cardiac output within the body.
This document provides information on the structure and function of the kidney and renal circulation. It discusses the basic anatomy of the nephron and its parts including the glomerulus, proximal convoluted tubule, loop of Henle, distal convoluted tubule and collecting duct. It also describes the juxtaglomerular apparatus and its role in regulating blood pressure via the renin-angiotensin system. Regarding renal circulation, it notes the kidney receives a high blood flow and has a unique portal system, as well as features like autoregulation and high oxygen consumption.
this presentation comprises of everything about the process of defecation and the defecation reflex and the nerve supply involved.
also discusses about the types of defecation reflexes and deals about them seperately in detail.
This presentation is about normal wave patterns of JVP and their variations. It includes definition, mechanism, abnormalities and clinical significance of jugular venous pressure.
The arterial pulse is caused by the transmission of pressure waves along the arteries during ventricular systole. The pulse can be felt over arteries and provides information about heart rate, rhythm, and volume. The jugular venous pulse reflects right atrial pressure and is assessed by observing waves corresponding to atrial contraction and filling. Together, examining the arterial and jugular pulses provides clinical information about cardiovascular function and hemodynamics.
Useful for medical and biology students who want to study the cardiac cycle in a short time with big benefits !!
CVS physiology - Wigger Diagram - ECG of cardiac cycle - Heart sounds
The cardiac cycle refers to the sequence of events that occur with each heartbeat. It begins with spontaneous electrical excitation of the sinoatrial node which causes the atria to contract, pushing blood into the ventricles. The atrioventricular valves then close, initiating ventricular isovolumic contraction where pressure builds but volume does not change. When pressure surpasses aortic pressure, the semilunar valves open and ventricular ejection occurs, followed by rapid ventricular filling from the atria as the semilunar valves close and atrioventricular valves open. The cycle then enters diastasis as the remaining blood slowly fills the ventricles.
This document provides information on assessing vital signs, including pulse rate, rhythm, and blood pressure. It describes how to palpate pulses at different locations like the carotid, brachial, radial, femoral, popliteal, and dorsalis pedis arteries. Key aspects of the pulse that are assessed include rate, rhythm, force, volume, equality between sides, and delays. Peripheral pulses located in the extremities can indicate issues. Blood pressure is influenced by factors like blood volume, artery diameter and elasticity, cardiac output, age, exercise, and position. The ankle-brachial index test compares ankle and arm blood pressures to detect peripheral artery disease.
This document provides information on cardiovascular examination, specifically examining the arterial pulse. It defines an arterial pulse as the pressure wave felt along peripheral arteries with each left ventricular contraction. Key points discussed include the rate, rhythm, volume, and character of the pulse. Specific pulse abnormalities are defined, such as pulsus paradoxus, dicrotic pulse, and pulsus alternans. Methods for examining different peripheral pulses like the radial, brachial, femoral, and carotid are outlined.
The document discusses hemodynamics, which is the movement of blood in the blood vessels outside the heart. The main factors that regulate blood flow are pressure gradients, vessel diameter, length, and blood viscosity. Blood flow is directly proportional to vessel diameter and inversely proportional to length and viscosity. Arteries have thicker muscular walls than veins and carry blood at higher pressures. Veins have thinner, more distensible walls and store about 65% of the total blood volume at lower pressures. Laminar flow is smooth flow near vessel walls while turbulent flow occurs when flow becomes irregular, such as during stenosis. Maximum resistance to blood flow occurs in the arterioles.
Cardiac physical exam and innocent murmurs presentation june 2020rajasthan govt
The document discusses examination of the cardiovascular system by assessing arterial pulses. It defines arterial pulses and describes how to evaluate the rate, rhythm, volume, and character of pulses at different arterial sites. Specific pulse abnormalities are also outlined, such as pulsus paradoxus and bisferiens pulse, which provide clues to underlying cardiovascular conditions like constrictive pericarditis or aortic stenosis. The summary evaluates arterial pulses to examine cardiovascular function.
The document discusses examination of the cardiovascular system by assessing arterial pulses. It defines arterial pulses and describes how to evaluate the rate, rhythm, volume, and character of pulses at different arterial sites. Specific pulse abnormalities are also outlined, such as pulsus paradoxus and bisferiens pulse, which provide clues to underlying cardiovascular conditions like constrictive pericarditis or aortic stenosis. The summary evaluates arterial pulses to examine cardiovascular function.
Cardiac physical exam and innocent murmurs presentationrajasthan govt
The document discusses examination of the cardiovascular system by assessing arterial pulses. It defines arterial pulses and describes how to evaluate the rate, rhythm, volume, and character of pulses at different arterial sites. Specific pulse abnormalities are also outlined, such as pulsus paradoxus and dicrotic pulse. The summary evaluates arterial pulses to examine cardiovascular function.
The document describes the conducting system of the heart which initiates and spreads electrical impulses, including the SA node, AV node, bundle of His, and Purkinje fibers. It then explains the cardiac cycle, including the roles of the atria and ventricles, heart sounds, and how blood pressure and ECG readings can monitor cardiac function.
BACK TO BASICS - HEMODYNAMIC ROUNDS - TRICUSPID VALVEPraveen Nagula
This document discusses the analysis and interpretation of tricuspid valve function based on right atrial pressure waveforms. It describes the normal right atrial waveform and how various cardiac pathologies alter the waveform. Specific topics covered include normal waveform patterns, effects of cardiac rhythm, systolic regurgitant waves, pulsatile venous waves, and right atrial-right ventricular gradients. It emphasizes the importance of using simultaneous, precisely calibrated pressure measurements to accurately assess small gradients across the tricuspid valve.
The venous system contains about 70–80% of the circulating blood volume which is non-pulsatile. However, changes in flow and pressure caused by the right atrial and right ventricular filling produce pulsations in the central veins that are transmitted to the peripheral veins (e.g. jugular veins) and are opposite to the direction of the blood flow.
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The arterial pulse and blood pressure reflects the dynamics of the left side of the heart, while the jugular veins provide the information about the hemodynamic events from the right side of the heart-right atrial pressure during systole and right ventricular filling pressure during diastole.
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Hence, an accurate assessment of the venous pulse, the jugular venous pulse (JVP) reflects the dynamics of the right side of the heart.1
History ●
Lancis (1728) first described the cervical venous pulse of the external jugular vein in a patient with tricuspid regurgitation (see Table 16.1).
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However, the classic graphic recordings of the JVP were done by Chauvea and Marey (1863).
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But it was Potain (1869) who accurately described the wave pattern in the internal jugular vein.
Giant a Waves or Cannon Waves
These occur whenever the RA contracts against the closed TV during RV systole. Paul Wood described the giant a wave as ‘venous Corrigan’. Cannon waves may occur either regularly or irregularly and are most common in the presence of arrhythmias. ●
Regular cannon waves occur in – Junctional rhythm – Ventricular tachycardia (VT) 1:1 retrograde conduction – Isorhythmic AV dissociation
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Irregular cannon waves occur in – Complete heart block (see Fig. 16.6) – Classic AV dissociation –VT – Ventricular pacing – Ventricular ectopics
The document provides a review of examining pulse and jugular venous pressure (JVP). It defines pulse as the expansion and elongation of the arterial wall due to blood pressure, and JVP as the oscillating top of blood in the right internal jugular vein reflecting right atrial pressure changes.
When examining pulse, the rate, rhythm, volume, character, arterial wall condition, and peripheral pulses are assessed. Abnormal rhythms and characteristics like pulsus paradoxus are also described. Examining JVP involves observing the pressure level and waveform pattern. An elevated or changed waveform can indicate cardiac or pulmonary issues. The document outlines how to properly examine both pulse and JVP and interpret the findings.
1) The arterial pulse is caused by the pressure wave generated from left ventricular contraction and ejection of blood into the aorta. This pressure wave travels faster than blood flow through the arteries.
2) The characteristics of a normal pulse include a rate of 60-100 bpm, regular rhythm, and features of the pressure wave such as the anacrotic limb, dicrotic notch, and peak pressure before aortic valve closure.
3) Various abnormalities in pulse rate, rhythm, volume, and wave characteristics provide clues to underlying cardiovascular conditions such as aortic stenosis, which causes delayed upstroke, anacrotic pulse, and reduced volume; or aortic regurgitation, seen as a coll
Cardiac Physical Exam and Innocent Murmurs Presentation.pdfsonijayprakash28
Dr. J P Soni discusses the physical examination of the cardiovascular system. He describes in detail how to assess arterial pulses through palpation of different arteries such as the radial, brachial, femoral, carotid, and dorsalis pedis. Key aspects of pulse examination include evaluating rate, rhythm, volume, character, and comparing pulses between different locations. Abnormal pulse findings can provide clues about underlying heart conditions such as aortic stenosis or heart failure. Blood pressure measurement techniques are also outlined.
CVS physiology, all details with explanation easy to recall physiology of cardiovascular system. based on Ganong's Review of Medical Physiology. all the high-yield facts are there.
The cardiac cycle describes the repeating sequence of heart contraction and relaxation that pumps blood throughout the body. It has two main phases: diastole, where the heart relaxes and fills with blood, and systole, where the heart contracts to pump out blood. Specifically, it involves atrial diastole, atrial systole, ventricular diastole, and ventricular systole. The cardiac cycle ensures blood is continuously circulating at a rate of around 72 beats per minute, pumping approximately 5-6 liters of blood per minute known as cardiac output through the coordinated squeezing of the heart's left and right ventricles.
The cardiac cycle describes the sequence of events that occur with each heartbeat. It involves mechanical, electrical, and pressure changes in the heart. The cycle begins with ventricular relaxation and atrial filling in diastole. Upon electrical stimulation, the ventricles contract in systole to pump blood out of the heart. This is accompanied by characteristic pressure and volume changes in the chambers as well as events on an electrocardiogram like the P, QRS, and T waves. The cycle repeats with each heartbeat to sustain blood circulation.
The document summarizes cardiac physiology, including the cardiac cycle, electrical and mechanical events of the heart, ventricular structure and function, preload and afterload, cardiac output, the action potential, and neural control of cardiac function. Key points include a description of the cardiac cycle, how the electrocardiogram represents electrical events, factors that influence ventricular function like the Frank-Starling law, and how the autonomic nervous system regulates the heart through the sympathetic and parasympathetic pathways.
The small intestine is composed of three parts - the duodenum, jejunum, and ileum. The duodenum is about 25cm long and has four parts. It is connected to the liver and contains the duodenal papilla through which the common bile duct and pancreatic duct empty. The jejunum is around 2.5m long and makes up the middle section of the small intestine. It contains circular folds and finger-like villi that increase its surface area for absorption. The ileum is around 3.5m long and contains Peyer's patches. It connects to the large intestine at the ileocecal valve.
The oesophagus connects the mouth to the stomach through the pharynx. It is approximately 25cm in length and has three parts - cervical, thoracic, and abdominal. Food passes through the upper esophageal sphincter into the oesophagus, triggering peristalsis to push the food bolus through in 6-15 seconds. The lower esophageal sphincter then opens to allow the food to enter the stomach and closes behind it to prevent acid reflux. The oesophagus wall has four layers but lacks a serosa, and receives parasympathetic and sympathetic innervation to control sphincters and peristalsis.
1) The gastrointestinal tract is approximately 9 meters long and runs from the mouth to the anus, mechanically and chemically breaking down food.
2) The mouth contains taste buds that detect the five basic tastes and contains salivary glands that produce saliva to moisten food for swallowing.
3) Chewing and swallowing propel food through the esophagus and into the stomach through peristalsis, where further digestion will occur.
Describes the secretion and functions of Antidiuretic hormone, abnormalities associated with ADH secretion, reasons of SIADH etc in details with figures.
This document discusses the three phases of detoxification. Phase III involves efflux transporters that transport substances transformed in Phase II out of cells. The best known transporter is P-glycoprotein, which eliminates conjugated metabolites from tissues. Transporters play a dual role in Phase III and in first pass metabolism by eliminating compounds before circulation. During first pass metabolism in the liver and intestines, compounds are biotransformed before reaching systemic circulation, resulting in lower bioavailability. Deconjugation by intestinal bacteria can recycle some compounds back through the liver via enterohepatic circulation.
Second ppt on endocrine system, describing hypothalamus, pituitary and thyroid glands.
This describes the hormones from these glands and their mode of action etc
This is on the basic details of the endocrine system including the different types of hormones. It describes the mechanisms of actions of hormones. The general control mechanisms of hormone production and release are also included.
This ppt is about the variations in metabolic processes between different types of cells in different organs of our body. The reasons for the variations are also descried. This is the first set of slides on the topic.
Describes the different types of chemical messengers in mammalian body. This explains their synthesis and mode of action also. A short account of neurohormones and neuroendocrine function is also included.
Heme synthesis is the biochemical pathway that produces heme, an iron-containing molecule that is an essential part of hemoglobin. The pathway has many steps that occur in both the cytosol and mitochondria of cells. A deficiency in any of the enzymes or substrates involved can cause a condition called porphyria. The first reaction is the rate-limiting step of condensing glycine and succinyl-CoA to form delta-aminolevulinic acid (ALA). Subsequent steps modify ALA and its derivatives to ultimately form protoporphyrin IX. The last step is the insertion of an iron ion into protoporphyrin IX by the enzyme ferrochelatase to complete heme synthesis.
This presentation is about bioenergetics. It talks about energy changes and equilibrium during different biological reactions, how exergonic and endergonic reactions are combined as sequential reactions in body, how the body system is following the law of thermodynamics etc. Role of enzymes in thermodynamics is also explained
Describes the different pathways involved in the synthesis of different eicosanoids like prostaglandins, leukotrienes, lipoxins etc along with different enzymes involved.
Describes the process of ageing in cells, factors affecting cells like telomere, free radicals, oxidative stress, DNA damage, environmental factors, proteostasis, mitochondrial disfunction etc are described
The document discusses the Ramachandran plot, which shows statistically probable combinations of the phi and psi backbone torsion angles in proteins. It describes how these two angles describe rotations around bonds in the polypeptide backbone and influence protein folding. The plot reveals allowed and disallowed regions based on steric clashes between atoms at different angle combinations. Common structures like alpha helices and beta sheets correspond to allowed regions in the plot.
The gastrointestinal tract is approximately 9 meters long and runs from the mouth to the anus. It mechanically and chemically breaks down food. The document discusses the different parts of the GI tract including the mouth, tongue, taste buds, salivary glands, and swallowing process. It describes the roles and functions of these parts in digesting and moving food through the body.
Lipoproteins are complexes of lipids and proteins that transport lipids through the water-based blood system. They consist of a nonpolar lipid core of triglycerides and cholesterol esters surrounded by a single layer of amphipathic phospholipids and cholesterol. Apolipoproteins attached to the surface act as proteins. Lipoproteins are classified based on their density, which is determined by ultracentrifugation. The five major groups are chylomicrons, VLDL, IDL, LDL, and HDL.
This document summarizes the regulation of blood glucose levels. It discusses how blood glucose levels fluctuate after meals and during fasting states. The pancreas plays a key role by secreting hormones like insulin and glucagon that work to maintain normal blood glucose levels. Insulin promotes glucose uptake by cells to lower blood glucose, while glucagon has the opposite effect of raising blood glucose levels. The body uses negative feedback loops and other hormones to precisely control blood glucose levels through processes like glycogenesis and glycogenolysis in the liver.
Authoring a personal GPT for your research and practice: How we created the Q...Leonel Morgado
Thematic analysis in qualitative research is a time-consuming and systematic task, typically done using teams. Team members must ground their activities on common understandings of the major concepts underlying the thematic analysis, and define criteria for its development. However, conceptual misunderstandings, equivocations, and lack of adherence to criteria are challenges to the quality and speed of this process. Given the distributed and uncertain nature of this process, we wondered if the tasks in thematic analysis could be supported by readily available artificial intelligence chatbots. Our early efforts point to potential benefits: not just saving time in the coding process but better adherence to criteria and grounding, by increasing triangulation between humans and artificial intelligence. This tutorial will provide a description and demonstration of the process we followed, as two academic researchers, to develop a custom ChatGPT to assist with qualitative coding in the thematic data analysis process of immersive learning accounts in a survey of the academic literature: QUAL-E Immersive Learning Thematic Analysis Helper. In the hands-on time, participants will try out QUAL-E and develop their ideas for their own qualitative coding ChatGPT. Participants that have the paid ChatGPT Plus subscription can create a draft of their assistants. The organizers will provide course materials and slide deck that participants will be able to utilize to continue development of their custom GPT. The paid subscription to ChatGPT Plus is not required to participate in this workshop, just for trying out personal GPTs during it.
Current Ms word generated power point presentation covers major details about the micronuclei test. It's significance and assays to conduct it. It is used to detect the micronuclei formation inside the cells of nearly every multicellular organism. It's formation takes place during chromosomal sepration at metaphase.
ESA/ACT Science Coffee: Diego Blas - Gravitational wave detection with orbita...Advanced-Concepts-Team
Presentation in the Science Coffee of the Advanced Concepts Team of the European Space Agency on the 07.06.2024.
Speaker: Diego Blas (IFAE/ICREA)
Title: Gravitational wave detection with orbital motion of Moon and artificial
Abstract:
In this talk I will describe some recent ideas to find gravitational waves from supermassive black holes or of primordial origin by studying their secular effect on the orbital motion of the Moon or satellites that are laser ranged.
When I was asked to give a companion lecture in support of ‘The Philosophy of Science’ (https://shorturl.at/4pUXz) I decided not to walk through the detail of the many methodologies in order of use. Instead, I chose to employ a long standing, and ongoing, scientific development as an exemplar. And so, I chose the ever evolving story of Thermodynamics as a scientific investigation at its best.
Conducted over a period of >200 years, Thermodynamics R&D, and application, benefitted from the highest levels of professionalism, collaboration, and technical thoroughness. New layers of application, methodology, and practice were made possible by the progressive advance of technology. In turn, this has seen measurement and modelling accuracy continually improved at a micro and macro level.
Perhaps most importantly, Thermodynamics rapidly became a primary tool in the advance of applied science/engineering/technology, spanning micro-tech, to aerospace and cosmology. I can think of no better a story to illustrate the breadth of scientific methodologies and applications at their best.
hematic appreciation test is a psychological assessment tool used to measure an individual's appreciation and understanding of specific themes or topics. This test helps to evaluate an individual's ability to connect different ideas and concepts within a given theme, as well as their overall comprehension and interpretation skills. The results of the test can provide valuable insights into an individual's cognitive abilities, creativity, and critical thinking skills
The binding of cosmological structures by massless topological defectsSérgio Sacani
Assuming spherical symmetry and weak field, it is shown that if one solves the Poisson equation or the Einstein field
equations sourced by a topological defect, i.e. a singularity of a very specific form, the result is a localized gravitational
field capable of driving flat rotation (i.e. Keplerian circular orbits at a constant speed for all radii) of test masses on a thin
spherical shell without any underlying mass. Moreover, a large-scale structure which exploits this solution by assembling
concentrically a number of such topological defects can establish a flat stellar or galactic rotation curve, and can also deflect
light in the same manner as an equipotential (isothermal) sphere. Thus, the need for dark matter or modified gravity theory is
mitigated, at least in part.
Describing and Interpreting an Immersive Learning Case with the Immersion Cub...Leonel Morgado
Current descriptions of immersive learning cases are often difficult or impossible to compare. This is due to a myriad of different options on what details to include, which aspects are relevant, and on the descriptive approaches employed. Also, these aspects often combine very specific details with more general guidelines or indicate intents and rationales without clarifying their implementation. In this paper we provide a method to describe immersive learning cases that is structured to enable comparisons, yet flexible enough to allow researchers and practitioners to decide which aspects to include. This method leverages a taxonomy that classifies educational aspects at three levels (uses, practices, and strategies) and then utilizes two frameworks, the Immersive Learning Brain and the Immersion Cube, to enable a structured description and interpretation of immersive learning cases. The method is then demonstrated on a published immersive learning case on training for wind turbine maintenance using virtual reality. Applying the method results in a structured artifact, the Immersive Learning Case Sheet, that tags the case with its proximal uses, practices, and strategies, and refines the free text case description to ensure that matching details are included. This contribution is thus a case description method in support of future comparative research of immersive learning cases. We then discuss how the resulting description and interpretation can be leveraged to change immersion learning cases, by enriching them (considering low-effort changes or additions) or innovating (exploring more challenging avenues of transformation). The method holds significant promise to support better-grounded research in immersive learning.
ESPP presentation to EU Waste Water Network, 4th June 2024 “EU policies driving nutrient removal and recycling
and the revised UWWTD (Urban Waste Water Treatment Directive)”
2. Arterial pulse
A pulse represents the tactile arterial palpation of the heartbeat
The pulse may be palpated in any place that allows an artery to be
compressed against a bone such as;
at the neck (carotid artery),
on the inside of the elbow (brachial artery),
at the wrist (radial artery), at the groin (femoral artery
near the ankle joint (posterior tibial artery), and
on foot (dorsalis pedis artery)
Pulse (or the count of arterial
pulse per minute) is equivalent to
measuring the heart rate
The heart rate can also be
measured by listening to the heart
beat directly (auscultation),
traditionally using
a stethoscope and counting it for a
minute
3. Measuring pulse
• The radial pulse is commonly measured using
three fingers
• The study of the pulse is known as sphygmology
4. Pulse
• Pressure waves generated by the heart in systole move the arterial walls
• Forward movement of blood occurs and is enough to create a palpable
pressure wave
• The heart rate may be greater or lesser than the pulse rate depending
upon physiologic demand
• In this case, the heart rate is determined by auscultation or
audible sounds at the heart apex, in which case it is not the pulse
• The pulse deficit (difference between heart beats and pulsations at the
periphery) is determined by simultaneous palpation at the radial
artery and auscultation at the heart apex
• It may be present in case of premature beats or atrial fibrillation
• Pulse velocity, pulse deficits and much more physiologic data are readily
and simplistically visualized by the use of one or more arterial
catheters connected to a transducer and oscilloscope
• This invasive technique has been commonly used in intensive care since
the 1970s
5. Normal pulse rate
• Newborn (0–3 months old) - 100-150
• Infants (3 – 6 months) -90–120
• Infants (6 – 12 months) -80-120
• Children (1 – 10 years) -70–130
• children over 10 years & adults
including seniors -60–100
• well-trained adult athletes -40–60
6. Pulse
• Volume: The degree of expansion displayed by artery during diastolic and
systolic state is called volume. It is also known as amplitude, expansion or size
of pulse
• Hypokinetic pulse: A weak pulse signifies narrow pulse pressure
• It may be due to low cardiac output (as seen in shock, congestive cardiac
failure), hypovolemia, valvular heart disease (such as aortic outflow tract
obstruction, mitral stenosis, aortic arch syndrome) etc.
• Hyperkinetic pulse: A bounding pulse signifies high pulse pressure. It may be
due to low peripheral resistance
– (as seen in fever, anemia, thyrotoxicosis, hyperkinetic heart syndrome (de), A-V
fistula, Paget's disease, beriberi, liver cirrhosis), increased cardiac output,
increased stroke volume (as seen in anxiety, exercise, complete heart block, aortic
regurgitation), decreased distensibility of arterial system (as seen
in atherosclerosis, hypertension etc.
• The strength of the pulse can also be reported:
– 0 = Absent
– 1 = Barely palpable
– 2 = Easily palpable
– 3 = Full
– 4 = Aneurysmal or bounding pulse
7. Venous pressure
• The evaluation of the venous pulse is an integral part of the physical
examination as it
– reflects both the mean right atrial pressure and
– the hemodynamic events in the right atrium
• Factors influencing the right atrial and central venous pressure
(CVP) includes
– total blood volume
– the distribution of blood volume, and
– right atrial contraction
• Venous blood returning from the systemic capillaries is nonpulsatile
• Changes in flow and pressure caused by skeletal muscles and
respiratory pump are non-synchronous with the pulsatile activity of
the heart
8. Venous pressure
• Changes in flow and pressure caused by right atrial
and ventricular filling
• Produce pulsations in the central veins that are
transmitted toward the peripheral veins, opposite to
the direction of blood flow
• With the possible exception of the "c" wave, which is
the combined result of carotid arterial impact and
upward movement of the tricuspid valve
• the pulsations observed in the neck are produced by
right atria and ventricular activity
9. Venous pulse
• Normal venous pulse (JVP)
reflects phasic pressure changes
in the right atrium and consists
of three positive waves and two
negative troughs
• In considering this pulse it is
useful to refer to the events of
the cardiac cycle
• The positive presystolic "a"
wave is produced by right atrial
contraction and is the dominant
wave in the JVP particularly
during inspiration
10. Venous pulse
• During atrial relaxation, the venous pulse
descends from the summit of the "a" wave
depending on the PR interval, this descent may
continue until a plateau ("z" point) is reached
just prior to right ventricular systole
• More often the descent is interrupted by a
second positive venous wave, "c" wave, which
is produced by a bulging of the tricuspid valve
into the right atrium during right ventricular
isovolumic systole and by the impact of the
crowded artery adjacent to the jugular vein
• Following the summit of the "c" wave, the JV P
contour declines, forming the normal negative
systolic wave, the "x" wave
• The "x" descent is due to a combination of
atrial relaxation, the downward displacement
of the tricuspid valve during right ventricular
systole, and the ejection of blood from both the
ventricles
11. V wave in JVP
• The positive, late systolic "v" wave
in the JVP results from the increase
in blood volume in the venae cavae
and the right atrium during
ventricular systole when the
tricuspid valve is closed
• After the peak of the "v" wave is
reached, the right atrial pressure
decreases because of the
diminished bulging of the tricuspid
valve into the right atrium and the
decline in right ventricular pressure
which follow tricuspid valve opening
The latter occurs at the peak of the
"v" wave in the JVP
12. Y wave
• Following the summit of the "v" wave, there is a
negative descending limb, referred to as the "y"
descent or diastolic collapse
• due to the tricuspid valve opening in the rapid and
• flow of blood into the right ventricle
• The initial "y" descent corresponds to the right
ventricular rapid filling phase
• The trough of the "y" wave occurs in early diastole
and is followed by the ascending limb of the
"y"wave, which is produced by continued diastolic
inflow of blood into the right side of the heart
• The velocity of this ascending pressure curve
depends on the rate of venous return and the
distensibility of the chambers of the right side of
the heart
• When diastole is long, the descending limb of the
"y" wave is often followed by a small, brief,
positive wave, the "h" wave, which occurs just
prior to the next "a" wave.
13. JVP
• At times, there is a plateau phase
rather than a distinct "h" wave
• With increasing pulse rate the "y"
trough and the "y" ascent are
followed immediately by the next
"a "wave
• Usually -three visible major positive
waves ("a", "c", "v") and two
negative wave ("x", "y") when the
pulse rate is below 90 beats per
minute and the PR interval is
normal
• With faster heart rates there is
often fusion of the some of the
pulse waves and an accurate
analysis of the waveform is more
difficult
14. Circulation Time
• "Average time taken for a RBC (or injected dye*) to traverse the systemic
& pulmonary circulations, and return to the starting point".
• For example:
• Coronary route =10 sec
• Some routes = several minutes (extensive venous sinuses spleen, etc.)
• Body average = 40 -60 sec. (vol. of the cardiac output circulated
approximately once per min)
• Affected by:
• Circulation time is decreased by exercise,
arteriovenous shunting, reduced venous
pooling
• Most of time is spent in the veins; thus,
circulation time is more dependent on what
happens in the veins than in the arteries,
arterioles (i.e. vaso - venomotion)
15. Circulation time
• Measurement of the circulation time through the heart and lungs is one of the
most widely used tests of circulatory efficiency in clinical medicine
• As Wiggers pointed out, circulation time is not the time required for the blood to
make a complete circulation, because
– any given corpuscle has such a wide variety of paths over which to travel as to make
such a concept meaningless
• With many authors the term "circulation time" seems to imply a measure of the
mean velocity of flow of an injected substance from the point of injection to the
place of detection
• According to Blumgart -"the interval of time necessary for the fastest particle of a
foreign substance to traverse the shortest available path between the point of
injection and the place of detection
• it is almost universally recognized that as a clinical test the circulation time is
useful in both establishing diagnoses and following the course of disease
• It becomes prolonged in congestive heart failure and returns toward normal with
relief of failure
• it is usually normal or rapid in heart failure due to anemia, thyrotoxicosis, beriberi
and arteriovenous fistula
16. Factors affecting circulation time
• Blumgart demonstrated that the circulation time is affected by the
cross-sectional area of the pathway traveled, which in turn is a
function of the amount of blood in the pulmonary Circulation,
vascular bed and the condition of its vessels
• widening of the pathway will allow the same volume per unit time to
pass at a diminished speed
• narrowing of the vascular caliber significantly impedes flow, slowing
will occur
• Increasing minute output increases the rate of flow (and decreases
circulation time) if other factors remain the same
• Decreased cardiac output has the opposite effect
• Thus in myxoedema without heart failure the circulation time is
prolonged in association with a diminished cardiac output
• Conversely, circulation time is notoriously rapid in Grave's disease,
even with heart failure and dilatation of the vascular bed, both of
which would tend to prolong it
• This must be due to the marked increase in cardiac output which
commonly occurs in hyperthyroidism
17. Circulation time
• laminar flow must be minimal in a system with pulsations, changing
frictions, changing diameters, turns and branchings
• The viscosity of the blood will be reflected in the cardiac output,
dilution and cross-sectional parameters
• For example, in anemia the cardiac output increases and the blood
volume decreases with a resulting rapid circulation time
• Conversely, in polycythemia the cardiac output is normal, more RBC-
more viscous and so the circulation time may be prolonged
• Therefore, it would seem that the circulation time, as here defined, is
a function of;
– the cross-sectional area of the pulmonary vascular bed (controlled by the
volume of blood in the lungs)
– the cardiac output (itself affected by factors such as peripheral
resistance), and
– the amount of dilution of the injected mass by the blood in the heart and
lungs
– An additional factor -the time of injection to the phase of the cardiac and
respiratory cycles
18. Triple response of Lewis
• Evolution of inflammatory processes in the three points described by Lewis.
• The triple response of Lewis is a cutaneous inflammatory response that occurs
from firm stroking of the skin, which produces an initial red line, followed by a
flare around that line, and then finally a wheal
• The triple response of Lewis is due to the release of histamine
• Histamine, or 2-(imidazol-4-yl)ethanamine, is a dibasic vasoactive amine that is
located in most body tissues but is highly concentrated in the lungs, skin, and
gastrointestinal tract
• Histamine is derived from the decarboxylation of the aminoacid histidine, a
reaction catalyzed by the enzyme L-histidine decarboxylase
• Histamine is a small molecule, stored in granules of mast cells and basophils
19. Triple response
• 3 part response that consists of:
1) red reaction
• - occurs due to the relaxation of the pre-capillary sphincters leading to an increase in
blood flow
- relaxation of the pre-capillary sphincters is mediated by histamine, which is released
from mast cells (not nerves)
* the red reaction occurs within 30s
2) wheal
• The wheal refers to the swelling / local odema. It is due to:
1) histamine acting on the endothelial cells of the capillaries increasing their
permeability.
2) increase in capillary hydrostatic pressure caused by histamine's dilator effects at the
arteriole end and its constrictor effect at the venule end (so that fluid is not resorbed
back into the capillary)
• More fluid is leaving the capillary and less is being resorbed.
20. Flare
• Refers to the irregularly outlined area of red skin spreading
beyond the red line
- The flare is due to an axon reflex
- skin receptors in the epidermis are stimulated by the release
of histamine from mast cells
• The stimuli from the skin receptor travel up the sensory
neurone and relayed anti-dromically to the sensory neuron
from the arteriole
• The stimuli from the skin travel down the sensory neurone
from the arteriole and causes arteriolar dilation by releasing
substance P
• Substance P acts on arterioles and causes vasodilation,
increasing blood flow to the arterioles
• anti-dromic conduction: when impulses travel in the opposite
direction
• orthodromic conduction: when impulse conduction is in the
usual direction.