The cardiovascular system consists of the heart, blood vessels, and blood. The heart is a hollow muscular organ located in the chest that pumps blood through two circuits: systemic circulation and pulmonary circulation. It has four chambers - right and left atria and ventricles separated by valves. Blood vessels include arteries, which carry blood away from the heart, and veins, which carry blood back to the heart. The cardiovascular system also contains a conduction system that initiates and regulates the heartbeat, starting with the sinoatrial node. Blood vessels have three layers - tunica intima, media, and externa - that vary in thickness and composition between arteries and veins.
5. Gross Anatomy
• Conical hollow muscular organ
• 12 x 9 cm and weighs 300g males 250g
females
• 4 chambers
– Right and left atria
– Right and left ventricles
• Septum
– Interatrial septum
– Interventricular septum
7. Pericardium
• Fibroserous sac
– encloses heart and roots of the great vessels
• Consists of
– Fibrous pericardium
– Serous pericardium
• Parietal layer – fused with fibrous pericardium
• Visceral layer – fused to the heart
9. Pericardial Cavity
• Pericardial cavity
– Potential space between the parietal pericardium
and visceral pericardium
– Contains thin film of serous fluid
10. Wall of the Heart
• Three layers
– Epicardium
– Myocardium
– Endocardium
11. Position of the Heart
• Obliquely behind the body of the sternum
• 1/3 right to the median plane other 2/3 left to
the median plane
• Apex of the Heart
– Formed by left ventricle
– Directed downward, forward to the left
– Left 5th intercostal space 3 ½ inches lateral to
midsternal line (just medial to the left
midclavicular line)
12. • Base of the Heart
– Formed by left atrium and small part of right
atrium
– Opening of pulmonary veins
– Forms posterior surface of the heart
13. Right Atrium
• External extension – right auricle
• 3 main openings
– Superior vena cava
– Inferior vena cava
– Coronary sinus
• Interior
– Smooth posterior part
– Rough anterior/pectinate part ( musculi pectinati)
– Septal wall
• Receive blood from the whole body and pumps to
right ventricle through right AV orifice
14.
15. Left atrium
• External extension – left auricle
• Two Pulmonary veins opens into the atrium
each side of the posterior wall
• Interior
– Greater part smooth
– Musculi Pectinati - auricle
• Receive oxygenated blood from the lungs
– 4 pulmonary veins
• Pumps to left ventricle through left AV orifice
16.
17. Right Ventricle
• Receive blood from the right atrium
• Pumps to the lungs through pulmonary artery
• Interior
– Rough part ( inflowing part)– trabecular carneae
• Papillary muscles – finger like projections from the
ventricle wall
– Other end connects to cusps of AV valves through chordae
tendinae
– Smooth part ( out flowing part)- infundibulum
– 2 orifices – tricuspid, pulmonary
18.
19. Left Ventricle
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Receive oxygenated blood from the left atrium
Pumps into the aorta
Forms apex of the heart
Interior
– Rough part (inflowing)
– Smooth part(outflow) – Aortic vestibule
– 2 orifices – mitral , aortic
• Wall Thickness – Left ventricle>>> Right
Ventricle
21. Valves of the Heart
• 2 types of valves
• Atrioventricular Valves
– Left – bicuspid / mitral ( 2flaps)
– Right – tricuspid ( 3flpas)
– Papillary muscles and chordae tendinae prevent
them from eversion towards atria
• Semilunar Valves- aortic and pulmonary
– 3 cusps – directly attached to vessel wall
– Blood caught in cusps push them to close position
30. Conduction system of the Heart
• Consists of modified cardiac muscle cells
which are specialized for initiation and
conduction of cardiac impulse
• Consists of
– SA node
• cardiac pacemaker – impulse 70/min
• Located at junction of SVC at right atrium
– AV node
• Located at right posterior part of interatrial septum
• Only conduction pathway between atria and ventricles
