1. Chapter 15 Cardiovascular System
heart
blood vessels
Average Size of Heart
14 cm long
9 cm wide
15-2

2. Location of Heart posterior to sternum medial to lungs
anterior to vertebral column
base lies beneath 2nd rib
apex at 5th intercostal space
lies upon diaphragm
15-3

3. Coverings of Heart
15-4

4. Wall of Heart Three layers endocardium myocardium epicardium
forms protective inner lining
membrane of epithelial and connective tissues
myocardium
cardiac muscle
contracts to pump blood
epicardium
serous membrane
protective covering
contains capillaries and nerve fibers
15-5

5. Heart Chambers Right Atrium receives blood from Left Atrium
inferior vena cava
superior vena cava
coronary sinus
Left Atrium
receives blood from pulmonary veins
Right Ventricle
receives blood from right atrium
Left Ventricle
receives blood from left atrium
15-6

6. Heart Valves Tricuspid Valve right A-V valve
between right atrium and right ventricle
Bicuspid Valve
left A-V valve
between left atrium and left ventricle
Pulmonary Valve
semilunar valve
between right ventricle and pulmonary trunk
Aortic Valve
semilunar valve
between left ventricle and aorta
15-7

7. Coronal Sections of Heart
15-8

8. Heart Valves
Tricuspid Valve
Pulmonary and Aortic Valve
15-9

9. Skeleton of Heart fibrous rings to which the heart valves are attached
15-10

10. Path of Blood Through the Heart
15-12

11. Path of Blood Through the Heart
15-11

12. Blood Supply to Heart
15-13

13. Cardiac Cycle Atrial Systole/Ventricular Diastole
blood flows passively into ventricles
remaining 30% of blood pushed into ventricles
A-V valves open/semilunar valves close
ventricles relaxed
ventricular pressure increases
Ventricular Systole/Atrial diastole
A-V valves close
chordae tendinae prevent cusps of valves from bulging too far into atria
atria relaxed
blood flows into atria
ventricular pressure increases and opens semilunar valves
blood flows into pulmonary trunk and aorta
15-17

14. Heart Actions Atrial Diastole/Ventricular Systole
Atrial Systole/Ventricular Diastole
Atrial Diastole/Ventricular Systole
15-16

15. Heart Sounds Lubb first heart sound
occurs during ventricular contraction
A-V valves closing
Dupp
second heart sound
occurs after ventricular contraction
semilunar valves closing
Murmur – abnormal heart sound
15-18

16. Heart Sounds
15-19

17. Cardiac Muscle Fibers Cardiac muscle fibers form functional syncytia
group of cells that function as a unit
atrial syncytium
ventricular syncytium
15-20

18. Cardiac Conduction System
15-22

19. Muscle Fibers in Ventricular Walls
15-23

20. Regulation of Cardiac Cycle
physical exercise
body temperature
concentration of various ions
potassium
calcium
15-28

21. Pulmonary Circuit
consists of vessels that carry blood from the heart to the lungs and back to the heart
15-50

22. Blood Flow Through Alveoli
cells of alveolar wall are tightly joined together
the high osmotic pressure of the interstitial fluid draws water out of them
15-51

23. Systemic Circuit
composed of vessels that lead from the heart to all body parts (except the lungs) and back to the heart
includes the aorta and its branches
includes the system of veins that return blood to the right atrium
15-52