anatomy of the heart

1. Anatomy ∙ Physiology
II
Chapter 15, Section 1
The Cardiovascular
System

2. FUNCTIONS OF THE
HEART
It pumps 7000L (1800 gallons) of blood through our body every day.
The heart contracts 2.5 billion times in a lifetime.

3. The heart is composed of two pumps
The systemic circuit carries
blood to the body
The pulmonary circuit carries
blood to the lungs

4. the heart is located within the mediastinum
It is about the size of a fist (14cm x 9cm)
2/3 of the heart is left of the midline
1/3
2/3

5. The heart is posterior to the sternum
Base
attachment of major vessels
2nd intercostal space
Apex
Pointed inferior margin
5th intercostal space

6. The heart is surrounded by a pericardial membrane.
The fibrous pericardium forms a thick outer
layer of connective tissue.
The parietal pericardium is a serous
membrane attached directly to the fibrous
layer.
A visceral pericardium is a serous
membrane that forms the outer layer of the
heart wall.
The pericardial cavity contains serous fluid.

7. The wall of the heart contains 3 layers
The epicardium is also called the visceral
pericardium
The myocardium contains a thick layer of cardiac
muscle, with blood vessels and nerves
The endocardium is a smooth layer of squamous
epithelium that lines the heart chambers and valves

8. The heart contains 4 chambers
The right atrium receives
blood from the body
The left atrium receives
blood from the lungs
The right ventricle pumps
blood towards the lungs
The left ventricle pumps
blood towards the body
Interventricular septum

9. A pocket on each atrium, called the auricle
increases the capacity of the atria.

10. blood enters the heart through the great veins
The superior vena cava
returns blood from the
upper body to the heart
Four pulmonary veins
return blood from the
lungs to the heart
The coronary sinus
returns blood from the
myocardium to the heart
The inferior vena cava
returns blood from the
lower body to the heart

11. Great arteries carry blood away from the heart
The aorta delivers oxygenated
blood to the systemic circulation
The pulmonary trunk* delivers
deoxygenated blood to the lungs
* The pulmonary trunk immediately
divides into a left and right pulmonary

12. Left and right AV valves prevent backflow into the atria.
*AV = atrioventricular
The tricuspid valve
guards the right AV
orifice
The bicuspid (mitral)
valve guards the left
AV orifice

13. AV valves are anchored to the ventricles by chordae tendineae
Chordae tendineae anchored to the
cusps papillary muscles
Papillary muscles contract to pull the
valves tightly shut
Mitral Valve Prolapse – cusp of the mitral valve protrudes into atrium.
Symptoms include: chest pain, heart palpitations, and fatigue.

14. Semilunar valves prevent backflow of blood into the ventricles
A pulmonary valve is located at
the base of the pulmonary trunk
An Aortic valve (not shown) is
located at the base of the aorta

15. Each cusp of a semilunar valve is
shaped like a crescent moon

16. path of blood through the right heart
1. Blood enters right atrium
through the SVC, IVC, and
coronary sinus
1
2. It passes through the tricuspid
valve into the right ventricle
4
4
3. Blood is pumped from the right
ventricle, through the pulmonary
valve, and into the pulmonary
trunk.
2
4. Blood passes into the
pulmonary arteries towards the
lungs
3
1

17. path of blood through the left heart
5. Oxygenated blood is returned to
the heart through 4 pulmonary
veins.
6. Blood enters the left atrium.
9
7. Blood passes through the
bicuspid valve into the left
ventricle.
8. The left ventricle pumps blood
through the aortic valve into the
aorta.
9. Blood enters systemic
circulation to the tissues
throughout the body.
9
9
8
5
5
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