ANATOMY lecture 11 :blood fo the circc. Flashcards
def of artery
bood moving away from heart
true or false: arteries branch to form smaller artereis?
truw
what is an arteriole
Small arteries <0.5 mm diameter = Arteriole
Where do arterials disperes their • O2 and nutrients
into Capillaries
wehre does diffusion take palce
cappilarries
what is the waste product of cellelur activaity picked up by
venules
what to venules join to form
veins
what are the 3 layers of an atery
tunica intima (interna) tunica media tunica extrema (adventitia)
expalin tunica interna
Inner layer formed by squamous epithelium
• Inner wall forms the hole (Lumen)
• Attached by connective tissue to the middle layer (tunica media)
explain tunica media
Thick intermediate layer formed by smooth muscle and elastic
tissue
explain tunia extrema (adventitia)
Outermost fibrous layer
• Can contain some smooth muscle
be able to label the layers of an artery
.
why are arteries flexible
because of the tunica media
what is it called when arteries harden with age?
arterioscleorsis
what is is called when Lumen narrowing due to deposition of fats on walls and what can it cause
Atherosclerosis
• Can cause a heart attack or stroke
explain anastomosis
• Small adjacent arteries can form to accommodate blood
flow
• Connecting arteries = ANASTOMOSIS
• Anastomosis is collateral circulation
what are capillary walls formed by
Walls formed by single layer of epithelial cells (simple
squamous) =tunica interna
what do capillaries form
Forms the most important part of the circulatory system
Ø CAPILLARY BED
what is the diamter of caps
1mm long x 8-10 microns diameter
where do capillaries locate
Between arterioles and venules
what happens at the capillaries
Essential exchange of materials to maintain consistency
of internal environment