Circulatory System

Functions

• Transport oxygen and carbon dioxide

• Distribute nutrients

• Transport wastes

• Distribute hormones

• Regulate body temperature

The Heart

Cardiac cycle

Systole – ventricle contraction

Diastole – relaxation of all chambers following contraction of atria

Blood’s Path Through the Heart - Deoxygenated

1. Vena cava

2. Right atrium

3. Right ventricle

4. Pulmonary Arteries

5. Lungs

Blood’s Path Through the Heart - Oxygenated

6. Lungs

7. Pulmonary Veins

8. Left atrium

9. Left ventricle

10. Aorta

11. Body

Influence on Heart Rate

• Nervous system

• Hormones

Functions of Blood

• Transport– Nutrients– Gasses– Hormones– Waste Products

• Immune Response

Blood Composition

• Plasma 55-60%

• Red blood cells – carry oxygen

• White blood cells - immunity

• Platelets – clotting

***Blood is mostly saltwater!***

Blood Vessels

• Arteries/arterioles – have smooth muscle in walls, take blood away from the heart

• Capillaries – very small, place where most gas exchange occurs

• Veins/venules – have valves, no muscle, take blood toward the heart