1. The circulatory system
Your body’s “internal transport system”!

2. What the Circulatory system does:
The heart moves blood through blood vessels.
Vessels move blood through the body to carry:
Oxygen
Carbon dioxide
Nutrients

3. What is blood made of? 55% = plasma
a clear liquid made up of 92% water
8 % is salts, nutrients, proteins and other chemicals
The rest of the blood = 3 kinds of blood cells
Red = carry oxygen to the body
White = protect the body from disease
Platelets = cell fragments that cause blood to clot

4. Hemoglobin = oxygen-carrying pigment in red blood cells
What color is blood???
Hemoglobin = oxygen-carrying pigment in red blood cells
Is bright red when attached to oxygen
Is dark red when doesn’t have oxygen
Veins appear blue b/c different colors of light reach different depths in the skin = the blue light is reflected back by the veins

5. How does the heart work? Beats constantly (no rest!)
It pushes blood through the vessels
Blood carrying carbon dioxide returns from the body and enters the right atrium of heart
Atrium = a chamber of the heart that RECEIVES blood
Blood is pushed to the ventricle = pushes blood OUT of the heart toward the lungs and other parts of the body

6. What makes the heart beat?
Contraction of the heart!
1. Signals at the top of the heart cause the heartbeat…
2. A group of cells called the “cardiac pacemaker” or S-A node start a signal…
3. The signal causes the atria to contract…
4. The signal is passed to cells in the a-v node and along to ventricles…
5. Ventricles contract…
Yeah= you have a heartbeat!

7. TYPES OF BLOOD VESSELS:
Arteries= Blood vessels that carry blood AWAY from the heart
Capillaries=
Tiny blood vessels that connect arteries to veins
Veins= Blood vessels that carry blood FROM all parts of body BACK to the heart