CIRCULATORY SYSTEM

Human physiology

THE CIRCULATORY SYSTEM

Body parts: heart, arteries, veins and capillaries

Function of circulatory system:• Pumps blood around your body

• Delivers food and oxygen• Takes away wastes

Circulation is the process of moving blood around

the body• The blood brings food and oxygen to all the body’s

cells• The blood carries waste away from the cells

Heart – the most important organ in the

circulatory system

PUMPING FOR LIFE

Heart: made up of four sections called chambers• Upper chambers are called atria• Lower chambers are called ventricles• each chamber pumps blood to the body

PUMPING FOR LIFE

BLOOD VESSELS

A blood vessel is a tube that carries blood around the body

Three different types of blood vessels:

1. Artery – blood vessels that carries blood away

from the heart to the body’s cells

2. Vein – blood vessel that returns blood to the heart

3. Capillary – tiny blood vessel that connects an

artery to a vein

- smallest blood vessels in body

- only one blood cell can pass at one time

BLOOD VESSELS

BLOOD

Blood is made up of a liquid part and three solid parts

Plasma – liquid part of blood• Mostly made up of water• Carries food molecules, wastes and other materials

3 types of solids:• Red blood cell – carries oxygen and carbon dioxide• White blood cell – fights bacteria and helps immune

system• Platelet – creates clots when you are bleeding

Heart

Veins (blue)

Arteries (red)

HEART DISEASE

Blood pressure is a measure of how hard it is for blood to get

through blood vessels

The narrower the blood vessels, the higher the pressure is.

High blood pressure can damage the heart and lead to heart

disease.

A heart attack happens when blood vessels to the heart muscles

become clogged.• The heart cannot get oxygen it needs and stops pumping• Without the heart pumping, the rest of the body isn’t getting the

oxygen it needs to stay alive

EXIT SLIP

1. What is the purpose of the

circulatory system?

2. What is the difference between an

artery and a vein?

3. Why is it important to keep blood

vessels to the heart muscle open?

Arteries carry blood away from the heart, a vein returns blood to the heart

Moves blood around the body

When the blood vessels become clogged, the heart muscle cannot get the oxygen it needs to pump