1. Structure and Blood Flow
The Heart
Structure and Blood Flow

2. Objectives 1. Be able to identify the structures of the heart.
2. Be able to discuss the functions and location of valves in the heart.
3. Be able to define pulmonary and systemic circulation.
4. Be able to explain the sequence of blood flow through the heart.
5. Be able to explain coronary circulation and coronary heart disease.

4. BCS
Brachiocephalic trunk
Carotid artery
Subclavian artery

5. Valves Keep blood from flowing back into a chamber of the heart
Located by entrance and exit of ventricles

6. Atrioventricular Valves
Separates atrial chambers from ventricles
Prevents backflow of blood into atria
Bicuspid (Mitral) on left side
Tricuspid on right side
Chordae tendineae- string-like structures that attach AV valves to the wall of the heart

7. Semilunar Valves
Between ventricles and large arteries that carry blood away from the heart when contraction occurs
Since ventricles contract together (atria also contract together) the two semilunar valves open and close at the same time

8. Pulmonary semilunar valve- at beginning of pulmonary artery (blood going to lungs); right ventricle
Aortic semilunar valve- at beginning of aorta; allows blood to flow out of the left ventricle up into the aorta but prevents backflow

9. Right
Left
“BALL”
ENTRANCE:
Atrioventricular Valves
Tricuspid
Bicuspid
(Mitral)
EXIT:
Semilunar
Valves
Pulmonary Semilunar
Aortic semilunar

10. Circulation
Pulmonary circulation-movement of blood from right ventricle to lungs
Systemic circulation-movement of blood from left ventricle to body

12. Sequence of Blood Flow
1. Oxygen poor blood from vena cavas to right atrium
2. Pass tricuspid valve to right ventricle
3. Pass pulmonary semilunar valve to pulmonary artery to lungs

13. 4. Oxygen-rich blood from lungs via pulmonary vein to left atrium
5. Pass bicuspid valve to left ventricle
6. Pass aortic semilunar valve to aorta

14. 7. From aorta throughout body via arteries, capillaries, and veins back to the heart

16. Coronary Circulation and Coronary Heart Disease
Blood, which supplies oxygen and nutrients to the myocardium of the heart, flows through the right and left coronary arteries
Blockage of blood flow through the coronary arteries can cause myocardial infarction (heart attack)

17. Coronary Circulation and Coronary Heart Disease
Atherosclerosis (type of “hardening of arteries” in which lipids build up on the inside wall of blood vessels) can partially or totally block coronary blood flow
Angina pectoris—chest pain caused by inadequate oxygen to the heart