Blood vessels Flashcards
Arteries carry blood…
away from the heart.
Veins carry blood…
towards the heart.
Capillaries link…
arteries and veins, take blood to tissues and cells.
Arteries transport blood at…
high pressure.
Arteries walls are made of…
- endothelium
- tunica media
- tunica externa
The endothelium is made of…
flat cells fitting together. The tissue is smooth, to reduce friction.
The tunica media contains…
smooth muscle, collagen and elastic fibres.
The endothelium is also called…
tunica intima.
Tunica Externa contains…
elastic fibres and collagen fibres.
Arteries are strong…
elastic and resilient.
Blood in arteries is transported at a pressure up to…
16 kPa
The walls of arteries are very…
thick compared to veins.
As the blood enters the artery at…
high pressure, the artery becomes wider, reducing the pressure a little.
An elasticity of arteries reduces…
the likelihood of bursting, when the heart pumps.
The artery walls stretch as…
As the high-pressure blood surges into them and then recoil backwards as the pressure drops.
Arterioles are…
Smaller branches of the artery, when it reach the tissue, where it transports blood.
Arterioles have greater proportion of…
Smooth muscle.
The smooth muscle in arterioles can…
Contract, narrowing the diameter and control the blood flow into a tissue.
The arterioles continue to branch into…
Capillaries.
Capillaries take the blood…
As close as possible to all cells, allowing a rapid exchange of substances between cells and blood.
Capillaries form a network throughout every…
Tissue except the cornea and cartilage.
Capillary beds are…
The networks of capillaries.
Diameter of capillary is…
7 micro meters in diameter same as blood cell.
Walls of capillaries are made of…
Very thin, single layer of endothelial tissue.
In endothelium walls there are…
Tiny gaps between the individual cells.
As the capillaries leave the tissue, they…
Join together, forming venules.
Venules join to form…
Veins.
Vein’s tunica…
media is thinner as it has fewer elastic fibres and muscle fibres.
Veins have semi…
Lunar valves, to prevent back-flow.
When the muscle around veins contracts…
The blood is squeezed up as it cannot pass down through closed valve.
The muscles around veins is called…
Skeletal muscle.
