1. Cardiovascular System APL2/L3

2.  Consists of: -a muscular pump, heart -a system of distribution vessels, arteries, veins and capillaries -a circulating fluid, blood

3. Cardiovascular System  Functions include: – transport of oxygen and carbon dioxide –delivery of food to cells removal of waste products from cells –distribution of hormones assists in maintenance of homeostasis e.g. temperature regulation

4. Workings of the heart  How much blood is in our body?  5-6 liters  What is average resting HR?  65-75 bpm  How much blood is pumped throughout the body every day?  7000 liters  Throughout one’s lifetime, heart can circulates 2.5 billion liters of blood

5. Blood Vessels Arteries  carry blood away from the heart  relatively thick walls to withstand higher blood pressure  smooth muscles modify diameter and thus regulate blood flow

6. Blood Vessels Veins  carry blood towards the heart  thinner walls than arteries, not subject to high pressure  contain one-way valves that regulate direction of blood flow

7. Blood Vessels Capillaries  connect arteries to veins  site of exchange between blood and surrounding tissues  walls one cell thick  extremely numerous, deliver blood close to all body cells

8. Coverings of the Heart  Double layered Pericardium –Visceral: inner, delicate lining on surface of heart –Parietal: outer, tough sac fitting loosely around heart  Pericardial cavity: space between 2 layers.  Filled with fluid to ↓ friction

9. Wall of heart: 3 Layers  Epicardium: protective outer membrane  Myocardium: middle, heart wall, rich in blood –Cardiac muscle  Endocardium: inner lining of heart wall –Purkinje fibers, collagen, elastin, BV’s

10. Human Heart  4 chambers: 2 atria and 2 ventricles  Atria receive blood from various parts of the body, and pump blood into the ventricles  Ventricles pump blood out to various parts of the body

11. LUNGS BODY Double Loop System

12. Heart chambers: Four  2 Atria: Thin walled upper chambers –Receive blood  2 ventricles: Thick walled lower chambers –Pump blood out  R. & L. sides separated by septum

13. Valves between Artia and Ventricles Valves between Artia and Ventricles  One set separates the atria & ventricles  Tricuspid: (3 cusps) –Separates Right atria and R. ventricle  Bicuspid: (2 cusps) –Seperates left atria & L. ventricle

14. Valves between ventricles and blood vessels out of heart  Another set separates the exiting blood vessels and the ventricles  Pulmonary valve: Right ventricle & pulm. Artery  Aortic valve: Left ventricle & aorta

15. Right Semilunar Valve Left Semilunar Valve Tricuspid Valve Bicuspid Valve Blood Flow on Right Side of Heart

16. Right Atrium Right Ventricle Left Atrium Left Ventricle Blood Flow on Left Side of Heart

17. Pulmonary Artery Aorta Vena Cava (2 veins) Pulmonary Veins (4 veins)

18. Pulmonary Artery – O 2 poor blood to lungs Aorta – O 2 rich blood to body Vena Cava – O 2 poor blood from body Pulmonary Veins – O 2 rich blood from lungs Path of Blood Flow in Heart

20. Quick Quiz: 10 points  1. What type of blood vessels: a. Carry blood low in oxygen back to the heart? b. Have higher BP and thick walls, high in oxygen? c. Are one cell thick ? 2. Why is the blood flow related to the heart considered a double-loop system? 2. Why is the blood flow related to the heart considered a double-loop system? 3. a. What valve is between the left atria and left ventricle? 3. a. What valve is between the left atria and left ventricle? b. What is another name for it? b. What is another name for it?

21.  4. What one of the four heart chambers have the thickest walls?  Why?  5. Blood from the body is received into the RA via what two large veins?