Blood Vessels Flashcards
What are blood vessels?
The tubes in the circulatory system.
what are the main types of blood vessels?
arteries, arterioles, capillaries, venules, veins
function of artery
carries blood away from the heart
function of veins
carries blood back to the heart
function of capillaries
allow exchange of substances between blood and surrounding tissues.
what is an arteriole?
small artery
what is a venue?
small vein
structure of arteries
Narrow lumen
Thicker walls
More collagen, smooth muscle and elastic fibres
No valves
structure of veins
Wide lumen
Thinner walls
Less collagen, smooth muscle and elastic fibres
Valves are present
what is collagen?
protein that provides strength and support to tissues
function of muscle tissue
Contracts to construct the lumen of arteries. This helps to maintain blood pressure.
function of elastic fibres
Stretch and recoil to maintain blood pressure in the arteries.
why do the walls of arteries have more collagen, muscle tissue and elastic fibres than veins?
arteries carry blood under a much higher pressure.
What is the endothelium?
The inner lining of blood vessels - a layer of flattened cells.
What is the function of the endothelium?
Reduces friction between the blood and the walls of the blood vessels.
