age 1 of 39
BIO 253 FINAL EXAM 3 STUDY GUIDE 2025/2026
COMPLETE QUESTIONS AND CORRECT DETAILED
ANSWERS WITH RATIONALES || 100% GUARANTEED
PASS <RECENT VERSION>
Elastic (conducting) arteries .....Answer.....Largest in the body.
Examples: Aorta and its major branches. Able to stretch without
injury. Accommodate a surge of blood when the heart contracts
and are able to recoil when the ventricles relax
Smooth Muscle Tissue .....Answer.....Present in all segments of the
vascular system except capillaries. Most abundant in elastic and
muscular arteries. Exerts active tension in vessels when
contracting
,age 2 of 39
Tunica externa .....Answer.....Found in arteries and veins (tunica
adventitia). Connective tissue
Tunica media .....Answer.....Found in arteries and veins. Smooth
muscle
Tunica intima .....Answer.....Found in all blood vessels. The only
layer present in the capillaries
Arteries .....Answer.....Carry blood away from heart; all arteries
except the pulmonary artery carry oxygenated blood
Muscular (distributing) arteries .....Answer.....Smaller in diameter
than elastic arteries. Thick muscular layer.
Arterioles (resistance vessels) .....Answer.....Important for
regulating blood flow to end organs
,age 3 of 39
Metarterioles .....Answer.....Short connecting vessels between true
arterioles and 20 to 100 capillaries
Capillaries Microscopic vessels .....Answer.....Carry blood from
arterioles to venules; together, arterioles, capillaries, and
venules constitute the microcirculation. Not evenly distributed.
Highest numbers in tissues with a high metabolic rate; may be
absent in some "avascular" tissues, such as cartilage.
Microcirculation .....Answer.....True capillaries receive blood flow
from the metarteriole, with input regulated by precapillary
sphincters
Three types of capillaries .....Answer.....Continuous capillaries
fenestrated capillaries and sinusoids
, age 4 of 39
Continuous capillaries .....Answer.....Have a continuous lining of
endothelial cells. Openings called intercellular clefts exist
between adjacent endothelial cells
Fenestrated capillaries .....Answer.....Have both intercellular clefts
and "holes," or fenestrations, through the plasma membrane to
facilitate exchange functions.
Sinusoids .....Answer.....Large lumen and tortuous course. Absent
or incomplete basement membrane. Very porous; permit the
migration of cells into or out of vessel lumen
Veins .....Answer.....Carry blood toward the heart. Act as
collectors and as reservoir vessels; called capacitance vessels.
Endothelial Tissue .....Answer.....One layer of squamous
endothelial cells. Provides a smooth luminal surface that protects
against intravascular coagulation. Intercellular clefts, cytoplasmic
BIO 253 FINAL EXAM 3 STUDY GUIDE 2025/2026
COMPLETE QUESTIONS AND CORRECT DETAILED
ANSWERS WITH RATIONALES || 100% GUARANTEED
PASS <RECENT VERSION>
Elastic (conducting) arteries .....Answer.....Largest in the body.
Examples: Aorta and its major branches. Able to stretch without
injury. Accommodate a surge of blood when the heart contracts
and are able to recoil when the ventricles relax
Smooth Muscle Tissue .....Answer.....Present in all segments of the
vascular system except capillaries. Most abundant in elastic and
muscular arteries. Exerts active tension in vessels when
contracting
,age 2 of 39
Tunica externa .....Answer.....Found in arteries and veins (tunica
adventitia). Connective tissue
Tunica media .....Answer.....Found in arteries and veins. Smooth
muscle
Tunica intima .....Answer.....Found in all blood vessels. The only
layer present in the capillaries
Arteries .....Answer.....Carry blood away from heart; all arteries
except the pulmonary artery carry oxygenated blood
Muscular (distributing) arteries .....Answer.....Smaller in diameter
than elastic arteries. Thick muscular layer.
Arterioles (resistance vessels) .....Answer.....Important for
regulating blood flow to end organs
,age 3 of 39
Metarterioles .....Answer.....Short connecting vessels between true
arterioles and 20 to 100 capillaries
Capillaries Microscopic vessels .....Answer.....Carry blood from
arterioles to venules; together, arterioles, capillaries, and
venules constitute the microcirculation. Not evenly distributed.
Highest numbers in tissues with a high metabolic rate; may be
absent in some "avascular" tissues, such as cartilage.
Microcirculation .....Answer.....True capillaries receive blood flow
from the metarteriole, with input regulated by precapillary
sphincters
Three types of capillaries .....Answer.....Continuous capillaries
fenestrated capillaries and sinusoids
, age 4 of 39
Continuous capillaries .....Answer.....Have a continuous lining of
endothelial cells. Openings called intercellular clefts exist
between adjacent endothelial cells
Fenestrated capillaries .....Answer.....Have both intercellular clefts
and "holes," or fenestrations, through the plasma membrane to
facilitate exchange functions.
Sinusoids .....Answer.....Large lumen and tortuous course. Absent
or incomplete basement membrane. Very porous; permit the
migration of cells into or out of vessel lumen
Veins .....Answer.....Carry blood toward the heart. Act as
collectors and as reservoir vessels; called capacitance vessels.
Endothelial Tissue .....Answer.....One layer of squamous
endothelial cells. Provides a smooth luminal surface that protects
against intravascular coagulation. Intercellular clefts, cytoplasmic
