Transcript The Circulatory System

THE CIRCULATORY
SYSTEM
Lesson 8
February 9-10th, 2010
The Circulatory System

Blood carries oxygen and food to the cells. It carries
carbon dioxide and other wastes away from the
cells. The job of the circulatory system is to move the
blood throughout your body.
Parts of the circulatory system
1. Heart – Muscle that pumps blood
2.Arteries – Blood vessels that carry blood away
from the heart to body cells
3. Veins – Blood vessels that carry blood back to the
heart
4. Blood – Carries nutrients, oxygen, carbon dioxide
and waste to and from cells.
Questions:
1.
Which vessels carry blood away from the heart?
2.
Which vessels carry blood to the heart?
How does the circulatory system
work?

The heart squeezes and relaxes to pump blood. For
the following diagram use the numbers and arrows
to follow the path that blood takes.
How does the circulatory system
work?
1.
2.
3.
4.
The heart gets oxygen rich blood from the
lungs.
The arteries take the blood away from the
heart to the body cells
Veins return blood from the body cells to the
heart
The blood is them pumped through an artery
to the lungs to get more oxygen.
http://www.youtube.com/watch?v=
PgI80Ue-AMo
Questions:
1.
Where do arteries get oxygen?
2.
Where do veins get carbon dioxide?
3.
4.
When you exercise your heart rate increases. How
does this help your respiratory system?
Germs can enter the blood through a break in the
skin, such as a scratch. Why is it important to properly
bandage cuts or breaks in the skin?
HEART RATE AND BLOOD
PRESSURE

Your heart is a pump. When it squeezes, it pushes
blood through the arteries. The blood is forced out
of your heart under pressure. You can feel this rush
of blood when you check your pulse. Your pulse
measures your heart rate. Your heart rate is the
rate at which your heart beats. It is measured in
beats per minute.
Heart rate



Measure your heart rate using a stopwatch.
Find your pulse on the side of your neck. Use your
middle finger and ring finger
Then count the beats in one minute
Blood pressure

The force the heart uses to pump blood all over the
body is called Blood Pressure. Use a blood
pressure cuff to measure blood pressure.
Blood pressure

When you take a blood pressure reading, you get
two numbers, such as 120/80. You say “120 over
80”. The two numbers show the blood pressure at
two different parts of your heart’s pumping cycle.
Your heart takes turns squeezing and
then relaxing.


When the heart squeezes to pump blood, blood
pressure rises. This gives the first number called
systolic pressure.
When the heart relaxes, blood pressure drops. This
gives the second number, called diastolic pressure.
Questions: + blood pressure lab