Plugging the leak

The idea

Platelets circulating in blood plug leaks at points of injury by helping the blood to clot, minimising loss of blood and of pressure.

A scratched finger

You scrape your finger and it bleeds for a short time. After a while the bleeding stops by itself.

What do you think helps to stop the bleeding?

• Platelet cells in the blood
• The skin growing back at once
• The blood turning into water

A leak and a plug

Press Next step.

Self-repair

If the system of tubes develops a leak, blood is lost and pressure drops. Platelets in the blood help to prevent this. They circulate around the body, and at a point of injury they plug the leak by helping the blood to clot.

Platelets circulating in blood plug leaks at points of injury by helping the blood to clot, minimising loss of blood and of pressure.

Notes

Platelets in the blood plug leaks at points of injury by helping the blood to clot, minimising loss of blood and pressure.

Check yourself

What plugs leaks at points of injury in blood vessels?

Besides loss of blood, what would a leak lead to?

Where do platelets plug the leaks?

What do platelets help the blood to do?

• Platelets, by helping the blood to clot — correct. Yes!
• Red blood corpuscles, by carrying oxygen. Red blood corpuscles carry oxygen; the platelet cells plug the leaks.
• Plasma, by carrying food. Plasma transports food, carbon dioxide and nitrogenous wastes in dissolved form.
• A rise in oxygen. A leak would lead to a loss of pressure, which reduces the efficiency of the pumping system.
• A loss of pressure — correct. Yes!
• More platelets leaving the body for good. The book says a leak leads to a loss of pressure.
• In the alveoli. Alveoli are in the lungs, where gases are exchanged.
• In the villi. Villi are in the small intestine and absorb digested food.
• At the points of injury — correct. Yes!
• Clot — correct. Yes!
• Carry oxygen. Oxygen is carried by the red blood corpuscles.
• Dissolve food. Plasma carries food in dissolved form.