Class Notes on Circulatory System

CIRCULATORY SYSTEM

Circulatory System
– responsible for transporting material throughout the body
– transports nutrients, water, oxygen to body cells
– carries away waste and CO2
– 2 division:
1. Cardiovascular system – transports blood
2. Lymphatic system – transports fluid called lymph


3 Types of Blood Vessels
1. Arteries (red)
- carry blood away from the heart
- aorta (largest artery; takes blood with oxygen and delivers it
to every part of the body)
2. Veins (blue)
- carry used blood back to the heart


3. Capillaries
- smallest type of blood vessel
- connects the rein and artery


Components of Circulatory
1. blood
2. heart – mainly composed of muscles, center of the circulatory system
3. blood vessels


Heart
– has 4 chambers (in blood flow order):
1. right atrium

, 2. right ventricle
3. left atrium
4. left ventricle
– carries 2 types of blood:
1. oxygen-rich blood travelling to the body cells; high oxygen content;
low CO2 content (left of the heart)
2. oxygen-poor blood travelling away from the body cells; low oxygen
(right of the heart)




Heart covering
– Pericardium
- covers the heart and large blood vessels attached to the heart
- visceral pericardium
 innermost layer
 directly on the heart
- parietal pericardium
 layer on top of visceral pericardium


Heart walls
– epicardium
- outermost layer
- fat to cushion the heart
– myocardium
- middle layer
- thick
- primarily cardiac muscle
– endocardium
- innermost
- thin, smooth
- stretches the heart as it pumps