human anatomy

1. The university of Georgia
Atheer Ahmed Abed 1330129
Human anatomy

2. THE
HEART

3.  Lies within the pericardium in middle mediastinum
 Behind the body of sternum and the 2nd to 6th costal
cartilages
 In front of the 5th to 8th thoracic vertebrae
 A third of it lies to the right of median plane and 2/3 to
the left
 Anterior to the vertebral column, posterior to the sternum
POSITION

4. HEART ANATOMY

5.  A hollow muscular organ, pyramidal in shape , somewhat
larger than a closed fist; consists of four chambers (right and
left atria, right and left ventricles)
 Cardiac Apex is formed by left ventricle and is directed
downwards and forwards to the left. It lies at the level of the
fifth left intercostal space, 1~2cm medial to the left
midclavicular line (9cm from the midline)
EXTERNAL CHARACTERISTICS

6.  The apex beat 【point of maximum impulse (PMI)】, is
the furthermost point outwards (laterally) and
downwards (inferiorly) from the sternum at which the
cardiac impulse can be felt.
 Lateral and/or inferior displacement of the apex beat
usually indicates enlargement of the heart, called
cardiomegaly
 Approximately the size of your fist
 Wt. = 250-300 grams
 Cardiac base is formed by the left atrium and to a small
extent by the right atrium. It faces backward, upward
and to the right
EXTERNAL CHARACTERISTICS

7. Two surfaces
 Sternocostal surface is formed mainly by the right atrium
and right ventricle, and a lesser portion of its left is formed by
the left auricle and ventricle. It is directed forwards and
upwards
 Diaphragmatic surface is formed by the ventricles－
chiefly the left ventricle, directed backwards and downwards,
and rests upon the central tendon of the diaphragm
Three borders
 Right border－vertical, is formed entirely by right atrium
 Left border－round, is mainly formed by the left ventricle
and partly by the left auricle
 Inferior border－horizontal, is formed by the right ventricle
and cardiac apex

8. Four grooves
 Coronary sulcus (circular sulcus) which marks the division
between atria and ventricles, contains the trunks of the coronary
vessels and completely encircles the heart
 Interatrial groove －separates the two atria and is hidden by
pulmonary trunk and aorta in front
 Interventricular grooves － anterior and posterior, mark the
division between ventricles (which separates the RV from the LV),
the two grooves extend from the base of the ventricular portion to a
notch called: the cardiac apical incisure

9.  Pericardium – a double-walled sac around the heart
 Composed of:
 A superficial fibrous pericardium
 A deep two-layer serous pericardium
 The parietal layer lines the internal surface of the fibrous
pericardium
 The visceral layer or epicardium lines the surface of the heart
 They are separated by the fluid-filled pericardial cavity called the
pericardial cavity
 Protects and anchors the heart
 Prevents overfilling of the heart with blood
 Allows for the heart to work in a relatively friction-free environment
COVERING OF THE HEART

10. Interatrial septum
 Located between right and left atria
 Contains fossa ovalis
Interventricular septum Located between right and left ventricles
 upper membranous part
 thick lower muscular part

11. Lecture on Anatomy of the Heart ( drnnamanisamuel@gmail.com)

12. PERICARDIAL LAYER

13.  Epicardium – visceral pericardium
 Myocardium – cardiac muscle layer
forming the bulk of the heart
 Endocardium – endothelial layer of the
inner myocardial surface
LAYERS OF THE HEART WALL

14. XRAY
NORMAL LVH（ Left ventricular hypertrophy ）

15. FRONTAL SECTION

16.  Atria - receiving chambers of the heart
 Receive venous blood returning to heart
 Separated by an interatrial septum (wall)
 Foramen ovale - opening in interatrial septum in fetus
 Fossa ovalis - remnant of foramen ovale
 Each atrium has a protruding auricle
 Pectinate muscles mark atrial walls
 Pump blood into ventricles
 Blood enters right atria from superior and inferior venae cavae and
coronary sinus
 Blood enters left atria from pulmonary veins
ATRIA OF THE HEART

17. Left auricle－projecting to the
right, pectinate muscles in wall
Four inlets－four orifices of
pulmonary veins open through the
posterior wall
One outlet－left atrioventricular
orifice, blood leaves through left
atrioventricular orifice to left
ventricle

18.  Ventricles are the discharging chambers of the heart
 Papillary muscles and trabeculae carneae muscles mark
ventricular walls
 Separated by an interventricular septum
 Contains components of the conduction system
 Right ventricle pumps blood into the pulmonary trunk
 Left ventricle pumps blood into the aorta
 Thicker myocardium due to greater work load
 Pulmonary circulation supplied by right ventricle is a much low pressure
system requiring less energy output by ventricle
 Systemic circulation supplied by left ventricle is a higher pressure system
and thus requires more forceful contractions
VENTRICLE OF THE HEART

20. It’s wall is three times thicker
than that of right ventricle
One inlet－left atrioventricular
orifice
One outlet－aortic orifice
Two parts－divided by anterior
cusps of mitral valve
Inflow tract－rough walls
Outflow tract – aortic
vestibule smooth area
leading to aortic orifice
Left ventricle

21. Interatrial septum
 Located between right and left atria
 Contains fossa ovalis
Interventricular septum Located between right and left ventricles
 upper membranous part
 thick lower muscular part
Fibrous skeleton
 Fibrous rings that surround the atrioventricular, pulmonary, and
aortic orifices
 Left and right fibrous trigons
SEPTUMS/FIBROUS SKELETON

22. ANTERIOR VIEW

23.  Heart valves ensure unidirectional blood flow through the heart
 Composed of an endocardium with a connective tissue core
 Two major types
 Atrioventricular valves
 Semilunar valves
 Atrioventricular (AV) valves lie between the atria and the
ventricles
 R-AV valve = tricuspid valve
 L-AV valve = bicuspid or mitral valve
 AV valves prevent backflow of blood into the atria when ventricles
contract
 Chordae tendineae anchor AV valves to papillary muscles of
ventricle wall
 Prevent prolapse of valve back into atrium
HEART VALVES

24.  Semilunar valves prevent backflow of blood into the ventricles
 Have no chordae tendinae attachments
 Aortic semilunar valve lies between the left ventricle and the aorta
 Pulmonary semilunar valve lies between the right ventricle and
pulmonary trunk
 Heart sounds (“lub-dup”) due to valves closing
 “Lub” - closing of atrioventricular valves
 “Dub”- closing of semilunar valves
SEMILUNAR HEART VALVES

25. Tricuspid valve
 Guards right atrioventricular orifice
 Three triangular cusps: anterior, posterior and septal, the base
of cusps are attached to fibrous ring surrounding the
atrioventricular orifice
 Chordae tendineae －fine, white, connective tissue cords,
attach margin of cusps to papillary muscles
Mitral valve
Guards left atrioventricular orifice
 Two triangular cusps－anterior and posterior with Similar
structures to those of right

26. Valve of pulmonary trunk
 Guards the orifice of pulmonary trunk
 Has three semilunar cusps – each with free border

27. POSTERIOR VIEW

28.  Cardiac muscle tissue has intrinsic ability to:
 Generate and conduct impulses
 Signal these cells to contract rhythmically
 Conducting system
 A series of specialized cardiac muscle cells
 Sinoatrial (SA) node sets the inherent rate of
contraction
CONDUCTING SYSTEM OF THE
HEART

29. CONDUCTING SYSTEM OF THE
HEART

30.  Heart rate is altered by external controls
 Nerves to the heart include:
 Visceral sensory fibers
 Parasympathetic branches of the vagus
nerve
 Sympathetic fibers – from cervical and
upper thoracic chain ganglia
INNERVATION

31. Sinuatrial node (SA node)
 Called the pacemaker cell (P cell)
 Located at the junction of right atrium and superior vena cava,
upper part of the sulcus terminalis, under the epicardium

32. Atrioventricular node (AV node)
 Located in the lower part of interatrial septum just above the
orifice of coronary sinus, under the endocardium
 Lower part related to membranous part of interventricular septum
Atrioventricular bundle (AV bundle)
 Passes forward through right fibrous trigon to reach inferior border
of membranous part
 Divides into right and left branches at upper border of muscular
part of interventricular septum

33.  Vessels returning blood to the heart include:
 Superior and inferior venae cavae
 Open into the right atrium
 Return deoxygenated blood from body cells
 Coronary sinus
 Opens into the right atrium
 Returns deoxygenated blood from heart muscle (coronary
veins)
 Right and left pulmonary veins
 Open into the left atrium
 Return oxygenated blood from lungs
MAJOR VESSELS OF THE HEART

34.  Vessels conveying blood away from the heart include:
 Pulmonary trunk
 Carries deoxygenated blood from right ventricle to lungs
 Splits into right and left pulmonary arteries
 Ascending aorta
 Carries oxygenated blood away from left atrium to body
organs
 Three major branches
 Brachiocephalic
 Left common carotid,
 Left subclavian artery
MAJOR VESSELS OF THE HEART

35. Lecture on Anatomy of the Heart ( drnnamanisamuel@gmail.com)
PATHWAY OF BLOOD THROUGH THE
HEART

36.  Coronary artery disease
 Atherosclerosis – fatty deposits
 Arteriosclerosis - hardening of the arteries
 Angina pectoris – chest pain
 Myocardial infarction – blocked coronary artery
 Silent ischemia – no pain or warning
 Fibrillation - irregular heart beat; may occur in either
atria or ventricles
DISORDERS OF THE HEART

37. Thank you for your
attention