Circulatory System NotesBiology - Mrs. Spinale/Kaye

The Circulatory System

Circulatory System Functions

● Blue = veins which carry deoxygenated blood to the heart and lungs.

● Red = arteries which carry oxygenated blood from the heart to the rest of the body.

Circulatory System Functions

● Carries food and nutrients such as glucose to the digestive system.

● Carries CO2 and O2 gases to and from the lungs.

● Carries waste to and from the kidneys.

Arteries

● Thick-walled and muscular.● Carry blood to the lungs and all over

the body.● Carries blood away from the heart.● Blood flows with high pressure.

Arteries

Arterial Damage

Veins

● Carry blood toward the heart.

● Valves prevent backflow.

● Not as muscular as arteries.

● Blood flows with low pressure.

Varicose Veins

Capillaries

● Very small tubes that connect veins and arteries.

● Thin walls exchange CO2 and O2, and water and solutes with cells.

● Small size keeps blood moving slow to allow for the exchange.

Capillaries

Blood and Its Components

● Plasma (fluid)● Red blood cells carry

oxygen.● White blood cells

fight disease.● Platelets create

clots.

The Heart

● The heart is a pump.● It has four chambers.

○ The upper chambers are called the Right and Left Atrium.

○ The lower chambers are called the Right and Left Ventricles.

The Heart

Path of Blood Flow through the Heart

● 1. Into the heart from the superior and inferior vena cava.

● 2. Into the right atrium.

● 3. Into the right ventricle.

Path of Blood Flow through the Heart

● 4. Out to the lungs through the pulmonary artery.

● 5. Back into the heart through the left atrium.

Path of Blood Flow through the Heart

● 6. Into the left ventricle.

● 7. Out to the rest of the body through the aorta.

Where Does the Blood Go?

● Deoxygenated blood goes to the heart.○ It is pumped to the

lungs where CO2 is unloaded and O2 is loaded into the blood.

Where Does the Blood Go?

● Oxygenated blood flows into the heart and is pumped to the rest of the body.

What Happens in the Lungs?

● CO2 is released and O2 is taken in as the alveoli is in contact with the veins and arteries.

What Happens in the Lungs?

The Exchange of Goods

● Everything that the blood transports and exchanges is based on many different concentration gradients.

● Dissolved gases, nutrients, water, and other solutes diffuse from high concentration to low concentration.