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BIOS 255
BIOS 255 EXAM 2 QUESTIONS WITH CORRECT
VERIFIED SOLUTIONS 100% GUARANTEED PASS
(LATEST UPDATE)
1. Tunica interna (intima): endothelial layer that lines the lumen of all
vessels 11. Tunica media: -smooth muscle and elastic fiber layer,
regulated by sympathetic nervous system
-controls vasoconstriction/vasodilation of vessels
2. Tunica externa: -collagen fibers that protect and reinforce vessels
3. Conducting arteries: the body's largest arteries; also called elastic
arteries
•thick-walled arteries near the heart; the aorta and its major branches
-large lumen allow low-resistance conduction of blood
-contain elastin in all three tunics
-withstand and smooth out large blood pressure fluctuations
-allow blood to flow fairly continuously through the body
BIOS 255
,4. Muscular arteries: distal to elastic arteries; deliver blood to body
organs
-have thick tunica media with more smooth muscle and less elastic
tissue -active in vasoconstriction
5 arterioles: smallest arteries; lead to capillary beds
-control flow into capillary beds via vasodilation and constriction
6. Capillaries allow only a _________ to pass at a time: single
rbc
7. Three structural types of capillaries: 1. Continuous capillaries
2. Fenestrated capillaries
3. Sinusoid capillaries (sinusoids)
8. Continuous capillaries: - are abundant in the skin and muscles,
and have:
-endothelial cells that provide an uninterrupted lining
-adjacent cells that are held together with tight junctions
-intercellular clefts of unjoined membranes that allow the passage of
fluids
, 9. Continuous capillaries of the brain: have tight junctions
completely around the endothelium
Constitute the blood-brain barrier
10. fenestrated capillaries: •found wherever active capillary
absorption or filtrate formation occurs (e.g., small intestines,
endocrine glands, and kidneys)
11. Fenestrated capillaries characterized by:: an endothelium
riddled with pores (fenestrations)
Greater permeability to solutes and fluids than other capillaries
12. Sinusoids: •highly modified, leaky, fenestrated capillaries
with large lumens
•found in the liver, bone marrow, lymphoid tissue, and in some
endocrine organs •allow large molecules (proteins and blood cells) to
pass between the blood and surrounding tissues
•blood flows sluggishly, allowing for modification in various ways
, 13. Capilary beds: interwoven network of capillaries between
arterioles and venules: -vascular shunts - metarteriole-thoroughfare
channel connecting an arteriole directly with a postcapillary venule
-true capillaries - 10 to 100 per capillary bed, capillaries branch off the
metarteriole and return to the thoroughfare
channel at the distal end of the bed 24.
Capillary beds sphincters open:
25. Capillary beds sphincters closed:
26 blood flow through capillaries: vasomotion
Slow, intermittent flow
Reflects on/off opening and closing of precapillary sphincters
27. Venules: •are formed when capillary beds unite
-allow fluids and wbcs to pass from the bloodstream to tissues
28. Postcapillary venules: smallest venules, composed of
endothelium and a few pericytes
BIOS 255
BIOS 255 EXAM 2 QUESTIONS WITH CORRECT
VERIFIED SOLUTIONS 100% GUARANTEED PASS
(LATEST UPDATE)
1. Tunica interna (intima): endothelial layer that lines the lumen of all
vessels 11. Tunica media: -smooth muscle and elastic fiber layer,
regulated by sympathetic nervous system
-controls vasoconstriction/vasodilation of vessels
2. Tunica externa: -collagen fibers that protect and reinforce vessels
3. Conducting arteries: the body's largest arteries; also called elastic
arteries
•thick-walled arteries near the heart; the aorta and its major branches
-large lumen allow low-resistance conduction of blood
-contain elastin in all three tunics
-withstand and smooth out large blood pressure fluctuations
-allow blood to flow fairly continuously through the body
BIOS 255
,4. Muscular arteries: distal to elastic arteries; deliver blood to body
organs
-have thick tunica media with more smooth muscle and less elastic
tissue -active in vasoconstriction
5 arterioles: smallest arteries; lead to capillary beds
-control flow into capillary beds via vasodilation and constriction
6. Capillaries allow only a _________ to pass at a time: single
rbc
7. Three structural types of capillaries: 1. Continuous capillaries
2. Fenestrated capillaries
3. Sinusoid capillaries (sinusoids)
8. Continuous capillaries: - are abundant in the skin and muscles,
and have:
-endothelial cells that provide an uninterrupted lining
-adjacent cells that are held together with tight junctions
-intercellular clefts of unjoined membranes that allow the passage of
fluids
, 9. Continuous capillaries of the brain: have tight junctions
completely around the endothelium
Constitute the blood-brain barrier
10. fenestrated capillaries: •found wherever active capillary
absorption or filtrate formation occurs (e.g., small intestines,
endocrine glands, and kidneys)
11. Fenestrated capillaries characterized by:: an endothelium
riddled with pores (fenestrations)
Greater permeability to solutes and fluids than other capillaries
12. Sinusoids: •highly modified, leaky, fenestrated capillaries
with large lumens
•found in the liver, bone marrow, lymphoid tissue, and in some
endocrine organs •allow large molecules (proteins and blood cells) to
pass between the blood and surrounding tissues
•blood flows sluggishly, allowing for modification in various ways
, 13. Capilary beds: interwoven network of capillaries between
arterioles and venules: -vascular shunts - metarteriole-thoroughfare
channel connecting an arteriole directly with a postcapillary venule
-true capillaries - 10 to 100 per capillary bed, capillaries branch off the
metarteriole and return to the thoroughfare
channel at the distal end of the bed 24.
Capillary beds sphincters open:
25. Capillary beds sphincters closed:
26 blood flow through capillaries: vasomotion
Slow, intermittent flow
Reflects on/off opening and closing of precapillary sphincters
27. Venules: •are formed when capillary beds unite
-allow fluids and wbcs to pass from the bloodstream to tissues
28. Postcapillary venules: smallest venules, composed of
endothelium and a few pericytes
