Cardiovascular System Anatomy

Objectives

• Introduction and Gross Anatomy

• Coronary Circulation

• Conduction System

• Arterial System & Venous system

• Histology of blood vessels

Introduction to CVS

• Components Of CVS

– Heart

– Blood Vessels

– Blood

• Two types of Circulation

– Systemic circulation

– Pulmonary circulation

Circulation

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

Gross Anatomy

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

Pericardium

Pericardial Cavity

• Pericardial cavity

– Potential space between the parietal pericardium and visceral pericardium

– Contains thin film of serous fluid

Wall of the Heart

• Three layers

– Epicardium

– Myocardium

– Endocardium

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)

• Base of the Heart

– Formed by left atrium and small part of right atrium

– Opening of pulmonary veins

– Forms posterior surface of the heart

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

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

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

Left Ventricle

• 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

Heart - Interior

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

Murmurs

• Turbulent flow through narrowed orifice cause abnormal sound

• Stenosis

– Mitral valve stenosis

– Aortic valve stenosis

• Regurgitation

– Aortic valve regurgitation

– Mitral valve regurgitation

Blood flow through the heart

Coronary Circulation

• Supply blood to the heart

• 2 coronary arteries

– Arise from the ascending aorta

• Right coronary artery

– Marginal

– Posterior interventricular

• Left coronary artery

– Anterior interventricular

– Circumflex

Coronary circulation

Veins of the heart ?

Veins of the heart ?

Arterial System

Venous System

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

Conduction system of the Heart

Histology of Blood vessels

Histology of Blood vessels

Cross section of artery wall

Cross section of small vein

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