1. Functional Organization of the Cardiovascular System

2. Objectives
Describe the functional organization of cardiovascular system
List the functions of cardiovascular system.
Describe the main function of arteries, capillaries and veins
Describe the flow of blood through the chambers of the heart and through the systemic and pulmonary circulations.
Compare and contrast the systemic and pulmonary circulation.

3. Functional Organization of Cardiovascular system
HEART
(PUMP)
CARDIOVASCULAR SYSTEM
VESSELS
(DISTRIBUTION
SYSTEM)
Blood

4. Functions of the Cardiovascular system
System circulates blood throughout the body.
Transport of nutrients, oxygen, and hormones to cells throughout the body and removal of metabolic wastes (carbon dioxide, nitrogenous wastes, and heat).
Protection of the body by white blood cells, antibodies, and complement proteins that circulate in the blood and defend the body against foreign microbes and toxins. Clotting mechanisms are also present that protect the body from blood loss after injuries.
Regulation of body temperature, fluid pH, and water content of cells.

5. THE HEART Anatomy of the heart
Hollow, muscular organ about the size of a clenched fist
Positioned between two bony structures – sternum and vertebrae
(CPR)

6. Heart: Two sided pump

11. Heart: 2 separate pumps (an atrium & a ventricle)
Rightpumps blood through lungs
Left pumps blood through peripheral
circulation
Atrium: weak primer pump for the ventricle
Ventricle: the main pumping force
 
Rt. Ventricle Lt. ventricle
Pulmonary circulation Systemic circulation

12. Blood Flow Through and Pump Action of the Heart

13. Pulmonary circulation
systemic circulation
Pulmonary circulation
Starts at left ventricle
Ends at right atrium
Receives blood from left side of heart
Carries blood between heart and other organ systems
Blood perfusing the organ systems is oxygenated
Part of the blood go to different organ systems
High pressure, high resistance
Starts at right ventricle
Ends at left atrium
Receives blood from right side of heart
Carries blood between heart and lungs
Blood perfusing the lungs is partially deoxygenated
All blood flows through lungs
Low pressure, low resistance

14. Heart Valves One way flow in heart is ensured by heart valves
Valves open & close passively
- open  by forward P by blood
- close  by backward P by blood
Prevent back flow of blood.

15. Heart Valves cont.. Atrioventricular (AV) valves (Tricuspid & mitral)
Prevent backflow of blood from ventricles into atria during ventricular emptying
Chordae tendinae
Fibrous cords which prevent valves from being everted
Papillary muscles

16. Heart Valves cont.. Semilunar valves (Aortic and pulmonary valves)
Lie at juncture where major arteries leave ventricles
Prevented from everting by anatomic structure and positioning of cusps
No valves between atria and veins
Reasons
Atrial pressures usually are not much higher than venous pressures
Sites where vecavae enter atria are partially compressed during atrial contractionnae

17. The fibrous skeleton of the heart
Serves 3 roles:
A mechanical base: atria anchored above and ventricles below
Perforated by 4 apertures, each containing a valve
Insulates the ventricles

18. Blood vessels

19. Arteries
Function:
Rapid transit passage-ways for blood from heart to tissues
Pressure reservoir
Structure of arterial wall
Plentiful of elastic fibers….high compliance

20. Arteriole Very small artery that delivers blood to capillaries
Structure
Very little elastic tissue but thick layer of smooth muscle
Function
Regulating blood flow from arteries to capillaries by regulating resistance according to tissue metabolic needs.
Contraction of smooth muscle (vasoconstriction) decrease arteriole diameter increase resistance decrease blood flow
Relaxation of smooth muscles (vasodilation) increase arteriole diameter decrease resistance increase blood flow

21. Capillaries Microscopic vessels that connects arterioles to venules
Structure
Single wall layered vesseles (endothelial cells)
Undergoes extensive branching
Function:
Exchange of nutrients and wastes between blood and tissue cells

22. Veins Carry blood from tissues to heart Structure: Thin wall
Less smooth muscle and considerable amount of collagen
Less elastic fibers
Function:
Passage ways back to heart
Blood reservoir (capacitance vessels)