The Circulatory System

The human circulatory system.

All cells in the body need blood.

Veins are blue and arteries are red.

Blood vessels

Your blood vessels help move blood around the body.

The small ones are called capillaries.

You have almost 100,000 kilometers of blood vessels in your body!

They bring oxygen to your muscles and organs.

veins

• Veins carry blood back to the heart. They do not have oxygen.

arteries

• Arteries carry blood away from the heart. • If you cut an artery, you are in a lot of danger.• Arterial blood has oxygen.

bloodThe blood carries oxygen and nutrients around the body. It also removes waste.

A 70 kg person will have about 5.5 liters of blood.

Blood becomes a solid when it clots. This is called a scab.

The heart

The heart pumps blood through your body.

It beats about 72 times per minute.

Medical words that start with “cardio” or “cardiac” are talking about the heart.

Heart attack

Heart diseases and heart attacks are the number one cause of death for Americans.

Stent to treat atherosclerosis

A stent is used for someone whose arteries are narrow or blocked.

Aneurysm หลอดเล�อดโป่งพอง

If you have a stroke or aneurysm, your brain may not get oxygen, and you could die.

Blood types

• There are four blood types: A, B, AB and O.• Most people in Asia are Rh positive.

Blood pressure

Blood cells

Red cells carry oxygen. White cells fight diseases.Platelets make your blood clot ล� ม

Donating Blood

You can donate blood at Roi-Et hospital.

You can help save someone’s life.

Maintaining body temperature-37 degrees

pulse ชี�พจร

You can check your pulse in many places.

The easiest is on your wrist and your neck.

When your heart moves its called a heartbeat.

Big animals have slower heartbeats.

A blue whale’s heart beats five times per minute.

A hummingbird’s heart beats more than 1200 times per minute.

Dizzy when you stand up?

Sometimes your blood will go down to your legs and away from your brain when you stand up.

It happens more if you’ve drank alcohol or ate a big meal.

Questions

• What is it called when your heart stops?• Where is a place you can donate blood?• What temperature should your body usually be?• Which brings blood away from the heart, veins or arteries?• What are the two kinds of blood cells and what do they do?• If you eat a lot of cholesterol, you may get ____ blood

pressure.• Which blood type can give blood to everyone?• About how many times does your heart beat every minute?• Why do we sometimes get dizzy when we stand up?• How many times does a whale’s heart beat per minute?