The Cardiovascular System
 A closed system of the heart and blood
vessels
 The heart pumps blood
 Blood vessels allow blood to circulate to all
parts of the body
 The function of the cardiovascular
system is to deliver oxygen and
nutrients and to remove carbon dioxide
and other waste products
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Slide 11.1
The Cardiovascular System
 Cells make the exchange of nutrients &
wastes only with the fluid in their
immediate vicinity.
 Changing & refreshing these fluids is
necessary to prevent buildup of wastes
and to replenish the nutrient supply
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Slide 11.1
The Heart
 Location
 Thorax between the lungs
 Posterosuperior base points toward right
shoulder beneath 2nd rib
 Pointed apex directed toward left hip, rests
on diaphragm at top of 6th rib
 About the size of your fist
 Weighs less than a pound: 250-350 grams
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Slide 11.2a
The Heart
Figure 11.1
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Slide 11.2b
The Heart: Coverings
 Pericardium – a double serous
membrane
 Visceral pericardium/epicardium
 Next to heart
 Parietal pericardium
 Outside layer
 Serous fluid (reduce friction) fills the
pericardial cavity: space between
layers of pericardium
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Slide 11.3
The Heart: Heart Wall
 Epicardium
 Outside layer
 This layer is aka the visceral pericardium
 Myocardium
 Middle layer
 Mostly cardiac muscle with fibrous CT support
 Actual contracting tissue layer
 Endocardium
 Inner layer
 Endothelium lining reduces friction and
continues into BV
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Slide 11.4
External Heart Anatomy
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Figure 11.2a
Slide 11.5
External Heart Anatomy
Pectinate
muscles
Chordae
Tendinae
Trabeculae
carnae
Papillary
Muscle
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Figure 11.2a
Slide 11.5
The Heart: Chambers
 Four chambers
 Atria - receiving chambers
 Right atrium – receives from body
 Left atrium – receives from lungs
 Thin walled – do not need great pumping
power
 Auricle – flap that increases atrial volume
 Foramen ovale: one structure that bypasses
fetal lungs. (ductus arteriosus is the other)
 Close up when infant starts breathing air –
become fossa ovalis and ligamentum
arteriosum (remnant structures)
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Slide 11.6
The Heart: Chambers
 Four chambers
 Ventricles - discharging chambers
Right ventricle – goes to lungs
Left ventricle – goes to body
Thick muscular walls – need pumping
power
Left ventricle pumps to entire body
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Slide 11.6
The Heart:
 Septum: divides heart into right
and left halves
 Superior vena cava: returns blood
to heart from head, shoulders, and
arms
 Inferior vena cava: returns blood to
heart from rest of body
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Slide 11.6
The Heart:
 Pulmonary trunk: BV out of right
ventricle to pulmonary arteries
 Pulmonary arteries: to lungs
 Pulmonary veins: back to left side
of heart
 Aorta: Largest Artery in body
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Slide 11.6
The Heart: Valves
 Allow blood to flow in only one direction
 Four valves
 Atrioventricular valves – between atria and
ventricles
 Papillary muscles: attached to chordae
tendineae to help prevent valves from
allowing backflow
 Bicuspid valve (left) – aka. Mitral valve
 Tricuspid valve (right)
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Slide 11.8
The Heart: Valves
Semilunar valves between
ventricle and artery
Pulmonary semilunar valve
(right)
Aortic semilunar valve (left)
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Slide 11.8
The Heart: Valves
Know how valves open & close to
prevent backflow of blood which is
important in keeping oxygenated &
deoxygenated blood from mixing and
gets them to the right structures.
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Slide 11.9
Operation of Heart Valves
Figure 11.4
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Slide 11.10
Heart Sounds
• Heart sounds - result from closing of
valves
• 1. Lub - AV valve closure – first
sound
• 2. Dup - semilunar valve
closure – second sound
The Heart
 Right and left side act as separate
pumps
 Pulmonary circuit – carries blood to lungs &
back – right side of heart
 Superior & inferior vena cava  rt. Atrium 
tricuspid valve  rt. Ventricle  pulmonary
SL valve  pulmonary trunk  pulmonary
arteries  lungs
 Systemic circuit – carries blood to body &
back – left side of heart
 Pulmonary veins  left atrium  bicuspid
valve  left ventricle  aortic SL valve 
aorta  body
 How the Heart Pumps
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Slide 11.11
Coronary Circulation
•blood contained in the heart does not
nourish the heart
•right & left coronary arteries and their
major branches supply blood to heart
•cardiac veins empty into coronary sinus
which drains into right atrium
•left ventricle works hardest so needs most
blood
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Slide 11.12
End of Quiz #1 Material
Know both your diagrams:
1. Heart parts
2. Pathway of circulation