Body Systems - 3.3 Circulation [ARCHIVE] Flashcards
(43 cards)
What does your circulatory system consist of?
- Heart (engine room, pumping continuously to keep blood moving)
- Blood vessels
- Blood
Why are the blood vessels important?
Blood carries all materials needed by the body through the blood vessels, which are all the roads along which blood flows.
What are the three types of blood vessels in the body?
- Arteries
- Veins
- Capillaries
What do the arteries do?
Arteries carry blood from the heart, moving it under pressure with each heartbeat.
How do arteries withstand the pressure from the beats of the heart?
Its walls are tough and elastic, bouncing back into shape after every beat.
What happens if an artery is cut?
The high pressure within it causes blood to spurt out quickly, so all major arteries are protected deep in the body.
What is the expansion and contraction of your arteries?
Your pulse.
What are capillaries?
Small blood vessels that branch out from arteries, they reach nearly every cell of the body and are only one cell thick.
What is good about the capillaries thin walls?
It allows dissolved materials to pass through them.
What do capillaries do?
Cells absorb nutrients and release waste into capillaries, which the heart pumps to remove.
What are veins?
Large blood vessels that are formed from capillaries that return blood back to the heart.
What do veins do?
Veins return blood to the heart; they have thin walls as pressure is lost in capillaries.
How is blood pushed back up to the heart?
By the contraction of the muscles of your body pressing against the veins.
What are valves?
Things along the length of the veins that make sure your blood flows in one direction.
What do valves do?
Open when blood is flowing toward the heart and close when it is flowing away.
What happens in your veins if you sit still for long periods of time?
The flow of the blood slows and pools, it may thicken and form a dangerous blood clot called a thrombosis.
What happens when you bump yourself hard?
Some tiny capillaries near the skin burst and blood leaks out into the surrounding tissue, a red mark appears where the blood has leaked. (bruises)
What happens as a bruise heals?
It fades to purple, then yellow as the blood is broken down and cleared away from the body.
What size and where is your heart?
It is about the size of your fist and situated in the middle of your chest, behind the breastbone.
What type of muscles is your heart made of and what does it do?
The cardiac muscle which does not get tired, it works continuously in response to the pacemaker.
Why is the circulatory system referred to as the double system?
As there are two separate circuits which the blood flows, both of them start with the heart.
How does the blood flow in one of the circuits of the system?
From the heart to the body and back to the heart. This circuit carries nutrients and oxygen to the cells and at the cells, collects waste.
What needs to happen for the circulatory system to work?
The blood rich in oxygen (oxygenated) and blood with carbon dioxide (deoxygenated) must be kept separate where the two systems meet in the heart.
How many chambers does your heart have and what do they do?
Four, two collect blood from the lungs and pump it round the body and the other two collect blood from the body and pump it to the lungs.
