Circulation in blood vessels Flashcards
Main type of blood vessels
Artery
Capillary
Vein
Connective tissues found in vessel walls: collagen
Its strengthen the blood vessel to withstand the pressure changes
Connective tissues found in vessel walls: smooth muscles
Controls the constriction & dilatation of blood vessels
Connective tissues found in vessel walls: elastic fibers
It allows the blood vessel to stretch to accommodate the greater volume of blood
Artery
Arteries carry blood away from the heart toward the cells in the body
Almost all arteries carry oxygenated blood except for pulmonary and umbilical artery
Artery - structure related to function: smooth endothelium lining
Arteries contain smooth endothelium lining to reduce friction between wall & blood
Artery - structure related to function: collagen
The wall of the arteries contain collagen layer to withstand high blood pressure
Artery - structure related to function: elastic fibres
The wall of the arteries contain elastic fibres allowing the arteries to stretch & recoil maintaining high bald pressure
Artery - structure related to function: smooth muscles
The smooth muscles in the artery wall enables the arteries to change diameter
Capillary
Capillaries connect arteries to veins
The primary function of capillaries is the exchange of materials between the blood and tissue cells
Capillary - structure related to function: no elastic fibres, smooth muscle or collagen
Capillary walls are thin & contain no elastic fibres, smooth muscles or collagen helping them to fit between individual cells & allowing rapid diffusion of substances between blood & the cells
Capillary - structure related to function: narrow lumen
It has a very narrow lumen so RBC can move in a single file increasing their SA during exchange of materials
Capillary - structure related to function:
Capillary walls contain single layer of epithelial cells so materials can be exchanged quickly
Capillary - structure related to function:
Contains microscopic pores on their walls allowing tissue fluid to leak through them
Vein
Veins carry blood towards heart
Most veins carry deoxygenated except pulmonary & umbilical vein
Vein:
The skeletal muscles contract to propel the blood in the veins towards the heart.
The semilunar valves prevent backflow of blood in the veins
Vein - structure related to function: thin wall
The thin wall of the veins (mainly contain collagen) as blood flow at low press
Vein - structure related to function: little smooth muscles
Little smooth muscles in the veins towards wall does not allow the veins to change diameter preventing stretching & recoiling
Vein - structure related to function: wide lumen
Veins have wide lumen allowing large volume of blood to flow without resistance
Vein - structure related to function: semilunar valves
Veins have semilunar valves that prevents backflow of blood
Comparison: muscle and elastic fibers
Arteries: they have thick layers of muscles & elastic fibers
Veins: they have thin layers of muscles mainly collagen and elastic fibers
Capillaries: they do not have muscle and elastic fibers
