Flashcards in 3.2 Blood Vessels Deck (26):
what is the sequence of blood vessels blood travels through?
(arteries) what layers does an artery have?
tough outer layer
thick muscle layer
thin inner lining
(arteries) the tough outer layer consists of what?
(arteries) the tough outer layer is strong and able to resist what?
pressure from outside the artery
(arteries) the thick muscle layer can do what?
contract to control blood flow
(arteries) the elastic layer helps maintain high pressure by doing what?
stretching and recoiling
(arteries) the thin inner lining is made of what?
(arteries) the inner lining is structured how?
smooth to prevent friction
deeply folded to allow expansion
(arteries)what is the lumen?
central cavity through which blood flows
(arterioles) smaller blood vessels control blood flow from where?
arteries to capillaries
(arterioles) what is the structure of arterioles?
smooth muscle - control blood flow
less elastic tissue
(capillaries) capillaries link what?
arterioles and venules
(capillaries) their small lumen is just the right size for what?
red blood cells to squeeze through one at a time
(capillaries) capillaries have no what?
(capillaries) their endothelium is one cell thick to allow for what?
(capillaries) capillary networks provide a large what?
surface area for diffusion
(capillaries) the total cross sectional area of capillaries is greater than arterioles so blood does what?
slows allowing more time for diffusion
(venules) smaller veins carrying blood where?
from capillaries to veins
(venules) they have very thin walls and what type of cells?
(veins) take blood where?
back to the heart at low pressure
(veins) why do veins have a thin layer of elastic tissue and thin muscle layer?
blood is at a lower pressure
(veins) why do they have a large lumen?
blood is at lower pressure and flows slower
(veins) valves in veins prevent what?
backflow of blood
(veins) many veins run between where?
(veins) when a muscle contracts what effect does it have on the vein?
squeeze it forcing blood back to the heart