The Circulatory System

Function

Consists of the heart and blood vessels

Carries oxygen and nutrients to the body’s cells and remove carbon dioxide and other wastes

Protects us from disease

Blood

Plasma – the liquid partRed blood cells –

contain hemoglobin, carry oxygen

White blood cells – fight invaders

Platelets – clot blood to stop bleeding

From Blood to Tissues

Substances move in and out of the capillaries by diffusionFood & oxygen passes into

cells from bloodCarbon dioxide & wastes

pass out of cells into blood

The Heart

Keeps blood moving through the circulatory system

Constantly beats by first squeezing & then relaxing

Heart beat: normally beats 65-75 beats per minute

Made of cardiac muscle

Structure of Your Heart

The human heart has 4 chambers with muscular walls

Atria – upper chambers – receive blood into the heart

Ventricles – larger lower chambers – pump blood out of the heart

1. Vein from upper body

1. Vein from lower body

2. Right atrium

3. Tricuspid valve

4. Right ventricle

5. Pulmonary valve

6. Pulmonary arteries

7. Pulmonary veins

8. Left atrium

9. Bicuspid valve

11. Aortic valve

10. Left ventricle

12. Aorta

The Movement of Blood

1. Veins from upper & lower body bring blood that is low in oxygen and high in carbon dioxide into the right atrium.

2. Right atrium pumps blood into the left atrium.

3. Right ventricle pushes the blood to lungs

4. In the lungs, blood picks up oxygen & releases carbon dioxide.

5. Oxygenated blood from lungs is carried to the left atrium.

6. the left atrium sends oxygenated blood into the left ventricle.

7. the left ventricle sends oxygenated blood into the aorta, the main artery leading to the body

8. Arteries carry oxygenated blood all over the body