Lecture 17
Cardiovascular System
The Heart
20-1
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
20-2
Pericardium
Fig. 22.3
20-3
External Anatomy
• Four chambers
– 2 atria
– 2 ventricles
• Auricles
• Major veins
– Superior vena cava
– Inferior vena cava
– Pulmonary veins
• Major arteries
Fig. 22.5
– Aorta
– Pulmonary trunk
20-4
External Anatomy
Fig. 22.5
20-5
Heart Valves
• Atrioventricular
– Tricuspid
– Bicuspid or mitral
• Semilunar
– Aortic
– Pulmonary
• Chordae tendineae
• Papillary muscles
Fig. 22.6
20-6
Heart Valves
Tricuspid valves
Bicuspid valves
Pulmonary
semilunar valves
Aortic semilunar
valves
20-7
Location of Heart Valves
Clinical View, pg. 664
20-8
Function of the Heart Valves
Fig. 22.13
20-9
Function of the Heart Valves
Fig. 22.13
20-10
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
20-11
Blood Flow Through Heart
Fig. 23.22
20-12
Systemic and Pulmonary
Circulation
Fig. 23.23
20-13
Points 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
20-14
Questions?
20-15