1. Cardiovascular System Notes:
The Heart

2. The human heart creates enough pressure to squirt blood 30 feet.
Interesting Cardiovascular System Facts
The human heart creates enough pressure to squirt blood 30 feet.

3. Review
What are the 3 parts of the cardiovascular system?
heart – blood – blood vessels
What do arteries do?
Take blood AWAY from the heart
What are the 3 layers of an artery?
Tunica externa /connective tissue (elastin) – tunica media/smooth muscle – tunica intima/endothelium
What do veins do?
Bring blood TOWARD the heart
What do veins have that arteries don’t?
VALVES – (veins & arteries both have the same layers except the muscular layer is smaller)

4. What exchanges material between blood and the body’s cells?
CAPILLARIES
How big are they?
microscopic in size

5. NOTES – THE HEART
Location:
cavity between the lungs, 2/3 left of midsagittal
roughly the size of a fist

6. Heart Anatomy
PERICARDIUM
outer membrane of the heart
2 layers
1. Parietal pericardium: external (outer) layer
2. Visceral pericardium (epicardium): part of the heart wall

7. Functions:
protection – physical barrier
anchors heart to other structures
provides lubrication to reduce friction – allows the heart to beat easily

8. THE HEART WALL
3 layers
1. Epicardium: outer portion (visceral pericardium)
EPICARDIUM

9. 2. Myocardium: middle layer consists of twisted cardiac muscle
THIS IS THE LAYER THAT ACTUALLY CONTRACTS
MYOCARDIUM

10. 3. Endocardium: inner layer made of epithelial tissue

11. HEART CHAMBERS
4 chambers
Atrium (left/right atria)
divided by the INTERATRIAL SEPTUM
Function of Atria: receives blood from veins
(pig heart)

12. RIGHT ATRIA
receives blood from superior & inferior vena cava
blood that’s been used
oxygen poor – high in CO2

13. LEFT ATRIA
receives blood from pulmonary veins
coming from lungs
rich in oxygen

14. Ventricles (left/right)
muscular pumps – divided by INTERVENTRICULAR SEPTUM
(pig heart)

15. RIGHT VENTRICLE
receives blood from the right atria (O2 poor)
pumps blood to the lungs through the PULMONARY ARTERIES

16. LEFT VENTRICLE
receives blood (O2 rich) from the left atrium
pumps blood to the body through the AORTA

17. Systemic Circulation
heart – lungs – heart – body – heart

18. HEART VALVES (4)
allow for “one way” circulation
2 Atrioventricular Valves (AV valves)
1. Tricuspid Valve: between right atria and right ventricle

19. 2. Bicuspid or Mitral Valve: between left atria and left ventricle
heavier & stronger of the two

20. CHORDAE TENDINAE and papillary muscles stop valves from being folded backwards

21. 3. Pulmonary Semilunar Valve: between the pulmonary artery and right ventricle

22. 4. Aortic Semilunar Valve: between aorta and left ventricle