2. The main blood vessels
connected to the heart are the
• arteries, veins, and capillaries.
During blood circulation, the arteries carry blood
away from the heart. The capillaries connect the
arteries to veins. Finally, the veins carry the blood
back to the heart.
3. Arteries
• The inner layer of the arteries is very smooth so that
the blood can flow easily with no obstacles in its
path.
• The walls of the arteries are muscular to help the
heart pump blood.
• The arteries deliver the oxygen-rich
blood to the capillaries.
4. Capillaries
• The capillaries are very thin and fragile.
• The exchange of oxygen and carbon dioxide takes
place through the thin capillary wall.
5. Veins
Veins are something like arteries but not as strong
because they transport blood at a lower pressure.
The veins transport waste-rich blood back to the lungs
and heart.
• The valves inside the veins are important so that
waste rich blood move in the proper direction.
6. Function of blood
• Blood carries oxygen from the lungs and nutrients from
the digestive tract to the body’s cells. And carries away
waste products.
• Helps keep your body at the right temperature
• Carries hormones to the body’s cells
• Sends antibodies to fight infection
• Contains clotting factors to help the blood to clot and
the body’s tissues to heal
7. Components of blood :
• Plasma
• Red blood cells
• White blood cells
• Platelets
8. Plasma
-Fluid part of blood
-Carries carbon dioxide, hormones and waste
Red blood cells
-Contain haemoglobin which carries oxygen
-Made in the bone marrow. The more you train
the more red blood cells are made.
-Carry oxygen to heart
9. White blood cells
-An important part of the immune system, they
produce antibodies and destroy harmful
microorganisms
-Made in the bone marrow
Platelets
-Clump together to form clots
-Protect the body by stopping bleeding
When exercising blood does the following
things:
-Transports nutrients and waste
-Delivers oxygen to the working muscles
-Removes heat (temperature regulation)
-Dilutes/carries away lactic acid (acidic balance)
