Blood Vessels Flashcards
(12 cards)
The direction of flow is kept up by
Pumping of the heart
In each organ what moves into the cells and what moves back into the blood
Sugar and oxygen moves into the cells and carbon dioxide back into the blood
Where do arteries carry the blood
Away from the heart
Arteries 3 points
Strong thick muscular walls to withstand high pressure as blood is pumped through all parts of the body.
Small lumen.
Thick layer of muscle and elastic fibres
Where do veins carry the blood
Carry’s blood back to the heart
Explain veins
Veins have relatively thin walls as they have low pressure .
Veins have valves to help keep the blood flowing in one direction back to the heart.
Large lumens
What do capillaries do
Very tiny vessel with narrow lumens
Capillaries allow substances to exchange at body cells e.g food and oxygens
Capillaries have very thin walls to allow these substances to leak through.
What is an arteriole
A small branch of an artery that leads into capillaries. It carries oxygen-rich blood toward the tissues and helps control blood pressure by constricting or dilating.
What is a venule
A small blood vessel that connects capillaries to veins. It carries oxygen-poor blood back toward the heart.
What happens to capillaries during gas exchange
Oxygen moves from the blood into tissues, and carbon dioxide moves from tissues into the blood.
List the blood vessels in order of blood flow (starting from the heart).
Artery → Arteriole → Capillary → Venule → Vein
How do arterioles regulate blood pressure?
By constricting (narrowing) or dilating (widening), which controls how much blood flows through them.
