Chapter 3: Lesson 1 Circulatory System

I.Circulatory System (Also known as the transportation system) A.It brings food and oxygen to body cells and removes cells’ wastes B.It includes 3 parts 1. Heart 2. Blood 3. Blood vessels

C. Blood 1. Made up of 4 parts a. Plasma- straw colored; carries food to your cells from digestive system b. Red blood cells- carry oxygen to your body’s cells c. White blood cells- work hard to protect body from germs and other harmful things. d. Platelets- cause blood clots to form to stop cuts from bleeding.

D. Types of Blood Vessels 1. Arteries a. carry blood away from your heart to other parts of your body. b. branch out into smaller tubes to carry blood with lots of oxygen 2. Capillaries a. smallest kind of blood vessel b. some can be so narrow, the cells move through in a single file line 3. Vein a. carry blood back to the heart b. have valves (flaps) that open and close to let blood flow in one direction

Cycle of the Circulatory System 1.Blood with CO2 enters the right atrium through a vein. 2.Blood with CO2 continues to the right ventricle 3.The valve between the right atrium and right ventricle closes. 4.Blood (CO2) is pumped through an artery to the lungs

5. Blood with oxygen (from the lungs) enters the left atrium through a vein. 6. Blood with O2 travels from the left atrium to the left ventricle. 7. The valve closes between the left atrium and the left ventricle. 8. Blood with O2 is pumped out the aorta to the rest of the body. 9. The cycle repeats from Step 1-8.