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Lecture 17

Cardiovascular System

The HeartThe Heart

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Size, Shape, Location of the Heart

• Size of a closed fist• Shape

– Apex: Blunt rounded point of cone

– Base: Flat part at opposite of end of cone

• Located in thoracic cavity in mediastinum

Fig. 22.2

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Pericardium

Fig. 22.3

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External Anatomy• Four chambers

– 2 atria– 2 ventricles

• Auricles• Major veins

– Superior vena cava– Inferior vena cava– Pulmonary veins

• Major arteries– Aorta– Pulmonary trunk

Fig. 22.5

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External Anatomy

Fig. 22.5

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Heart Valves• Atrioventricular

– Tricuspid– Bicuspid or mitral

• Semilunar– Aortic– Pulmonary

• Chordae tendineae• Papillary muscles

Fig. 22.6

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Heart Valves

Tricuspid valves

Bicuspid valves

Aortic semilunar valves

Pulmonary semilunar valves

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Location of Heart Valves

Clinical View, pg. 664

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Function of the Heart Valves

Fig. 22.13

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Function of the Heart Valves

Fig. 22.13

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Review Question

Damage to the mitral valve could result in an inefficient flow of blood from the _____________ to the _________________.

(a) Pulmonary trunk to right ventricle(b) Right atrium to right ventricle(c) Left ventricle to aorta(d) Right ventricle to left ventricle(e) Left atrium to left ventricle

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Blood Flow Through Heart

Fig. 23.22

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Systemic and PulmonaryCirculation

Fig. 23.23

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Points to RememberPoints to Remember• Heart is size of a closed fist and located in

mediastinum beneath rib cage• Heart is enclosed in pericardium with

pericardial fluid• Heart has four chambers: two atria and two

ventricles• Valves control flow of blood within and out

of heart• Heart is part of dual circuits for flow of

blood - systemic and pulmonary

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Questions?