1. The Circulatory System
Chapter 42: Part II

2. Human Circulatory System
a.k.a cardiovascular system 3 parts: 1. heart 2. blood 3. blood vessels

3. Human Circulatory System
Double Circulation: 1. systemic circuit – blood leaves heart and tours body 2. pulmonary circuit – blood leaves heart to go to lungs and back to heart

4. Human Circulatory System
Systemic Circuit Tour 1. Oxygenated blood leaves left ventricle via aortic semilunar valve & enters the aorta, the largest artery in the body

5. Human Circulatory System
Systemic Circuit Tour 2. Aorta branches into arteries 1. coronary arteries – supply O2 to heart 2. ascending arteries – supply O2 to head & arms 3. descending arteries – supply O2 to abdominal organs and legs
“Away, thick”

6. Human Circulatory System
Systemic Circuit Tour 3. Arteries  arterioles  capillaries Get smaller & smaller Capillaries: Where exchange of gases, nutrients, hormones, & waste occurs

7. Human Circulatory System
After exchange, blood is deoxygenated & needs to go to lungs, but first must go to heart. Capillaries  venules  veins Get larger and larger
Toward, thin

8. Human Circulatory System
Systemic Circuit Tour 4. Blood from superior body parts enters right atrium through superior vena cava Blood from inferior body parts enters right atrium through inferior vena cava

9. Human Circulatory System
Systemic Circuit Tour 5. Blood moves from right atrium to right ventricle through the right atrioventricular valve (tricuspid)

10. Human Circulatory System
Pulmonary Circuit Tour
6. From right ventricle blood goes out again through pulmonary semilunar valve and enters pulmonary artery
Carries deoxygenated blood to lungs
Branches into left and right pulmonary arteries
Arteries  arterioles  capillaries in alveoli

11. Human Circulatory System
Pulmonary Circuit Tour 7. Blood enters back into heart via pulmonary veins into left atrium

12. Human Circulatory System
Pulmonary Circuit Tour 8. Blood moves from left atrium to left ventricle through left atrioventricular valve (bicuspid, mitral)

13. Human Circulatory System
Recap of Systemic Circuit:
Blood leaves heart’s left ventricle via aorta
It travels through arteries  arterioles  capillaries of heart & superior/inferior body parts
Gas, nutrient/waste exchange occur between blood & tissues through capillary walls
Deox. blood leaves capillaries  venules  veins
It enters into heart’s right atrium via superior/inferior vena cava
it flows into hearts right ventricle via right atrioventricular valve (tricuspid)

14. Human Circulatory System
Recap of Pulmonary Circuit:
Deox. blood leaves heart’s right ventricle via pulmonary artery
Artery branches right & left into each lung
Blood travels from arteries  arterioles  capillaries of alveoli
Gas exchange occurs at alveoli
Oxygenated blood returns to heart’s left atrium through pulmonary veins
It flows into left ventricle through the left atrioventricular valve (bicuspid, mitral)