LECTURE exam 3- Ch.22 Flashcards
systemic circulation:
- arteries: O2 ____
- veins: O2 ____
rich; poor
pulmonary circulation:
- arteries: O2 ___
- veins: O2 ___
poor; rich
_______: walls have 3 layers (or tunica)
- adventitia
- media
- intima
arteries & veins
anchor blood vessels in place
adventitia
- labeled A
smooth muscle; used in vasoconstriction & vasodilation
media
- labeled B
endothelium of vessel
intima
- labeled C
most arteries & veins run ____ to each other
parallel
walls of arteries are ____ than veins
thicker
arteries have ____ smooth muscle than veins
more
arteries _____ their circular shape & veins typically ____ when cut
maintain; collapse
- endothelial lining has pleated folds
- thin elastic fibers in media
- external elastic membrane surrounding media
- internal elastic membrane surrounding intima
arteries only
- endothelial lining is smooth
- many have one-way valves to prevent backflow
veins only
a network of elastic fibers located between the intima and the media
internal elastic membrane
media is separated from the adventitia by the _____, a band of elastic tissue
external elastic membrane
- elastic
- muscular
- arterioles
types of arteries
- largest arteries ~1 inch
- contain elastic membranes in media & intima
- very resilient, tolerate pressure changes during cardiac cycle
- recoil during diastole helps propel blood forward
- examples: aorta / brachiocephalic trunk / pulmonary trunk
elastic arteries
- medium sized ~ pencil
- thicker media than elastic
- vessel diameter under control of autonomic nervous system & hormones
- examples: external carotid / brachial / femoral / mesentric
muscular arteries
- smallest (microscopic, ~30 microns)
- very thin adventitia
- media may have incomplete smooth muscle layers
- control blood flow b/w arteries & capillaries
arteriole
- smallest of all vessels (~8 microns)
- most delicate; lack adventitia & media
- only vessels where material exchange occurs b/w blood & tissues/interstitial fluid
capillaries
- continuous
- fenestrated
- sinusoids
types of capillaries
- endothelial lining complete
- most common
- single cell lined
continuous capillaries
-endothelial lining not complete
-rapid fluid & solute diffusion
fenestrated capillaries
-flattened
-endothelial lining NOT complete
-pores & large gaps
-slow blood movement
-diffusion of very large solutes
sinusoid capillaries
- Diffusion across endothelial cells
- Diffusion through gaps between adjacent endothelial cells
- Diffusion through pores
- Vesicular transport
capillary exchange
nonpolar solutes; gasses; water via aquaporins
diffusion across endothelial cells (capillaries)
small solutes; water; large solutes (in sinusoids)
diffusion through gaps b/w adjacent endothelial cells (capillaries)
solutes; water
diffusion through pores (capillaries)
water; targeted molecules (bound & unbound)
vascular transport (capillaries)
mesh of capillaries; connecting arterioles with venules
capillary beds
come together to form arterial anastomosis
collateral arteries
allow multiple supply routes to capillary beds
arterial anastomosis
contracting or relaxing ____ ____ determines blood flow
smooth muscle
-Arteriovenous anastomoses
-Thoroughfare channels
-Metarterioles
control of capillary flow