1. Heart Objectives Describe the location and surface anatomic
features of the heart
Compare and contrast the two major circulatory systems in the human body
Diagram, without reference to your notes or book, the path of blood flow through the heart and lungs
Identify the major blood vessels, chambers and valves of the heart

2. Systemic Circulation
–Carries oxygenated blood from the aorta to the tissues
the left ventricle ejects blood into the aorta
The blood is distributed to 6 major
organ systems: brain, heart, kidneys,
muscle, GI system, and skin
The circulatory system is often described
as a “tree”
– Blood vessels are arranged in parallel

3. The Pulmonary Circulation
the pulmonary circulation carries
deoxygenated blood (venous blood) to
the lungs and then back to the heart
the right ventricle ejects blood into the
pulmonary circulation
blood leaving the pulmonary circuit
(arterial blood) enters the left atrium

5. Summary Pulmonary circulation:
Path of blood from right ventricle through the lungs and back to the heart.
Systemic circulation:
Oxygen-rich blood pumped to all organ systems to supply nutrients.
Rate of blood flow through systemic circulation = flow rate through pulmonary circulation.

7. Systemic and pulmonary circulation

9. The Cardiac Output
the amount of blood pumped by the ventricles per unit time
under resting conditions, the left and right ventricles each pump about 5 liters of blood per minute
this value can be increased to as much as 30 liters per minute during maximal exercise

10. Superficial Anatomy of the Heart
the heart is located behind the sternum, above the diaphragm
2/3 of the mass lies left of midline, and the apex points down and to the left.
the heart is about 5 inches long, 3.5 inches wide and 2.5 inches thick
the great vessels that emerge from the heart include the pulmonary arteries and veins, the aorta, and the superior and inferior vena cava.

11. Chambers of the Heart The mammalian heart is composed of four chambers
– the right atrium
– the left atrium
– the right ventricle
– the left ventricle
• the left ventricle has much more muscle and
is much thicker than the right ventricle

12. Note: wall of left ventricle is thicker than right ventricle

13. Heart Valves the heart has four “one-way” valves
The valves insure that the blood flows in one
direction, from heart to tissues and back to the heart
two atrioventricular valves (between atria and
ventricles)
two semilunar valves (between LV and aorta
and between RV and pulmonary trunk)

15. Atrioventricular Valves
the left AV valve is also called the bicuspid or mitral valve, and separates the left atrium and left ventricle
the right AV valve is also called the tricuspid valve, and separates the right atrium and right ventricle

17. Semilunar Valves
The aortic semilunar valve separates the left ventricular chamber from the aorta.
the pulmonary semilunar valve separates the
right ventricular chamber from the main pulmonary trunk.
these valves are pressure dependent, meaning that they open and close in response to pressure differences in the vessels and ventricular chambers.

18. Pressure-dependent Valve Function
Aortic Pressure = 90 mmHg
Ventricular Pressure =
85 mmHg;
valves closed and
blood is not ejected
Aortic Pressure = 100 mmHg
Ventricular Pressure =
101 mmHg;
valves open and
blood is ejected

19. Blood Supply to Heart Muscle
the tissues of the heart are supplied with blood from the right and left coronary arteries
the right coronary artery originates on
the ascending aorta
the left coronary artery also originates
on the ascending aorta