BIOL 204 LECTURE EXAM 2 2026 QUESTION
COLLECTION DNA REPLICATION AND PROTEIN
SYNTHESIS MODULE SOLVED ITEMS AND
RESPONSE KEY
◉ why does the tunica externa contain connective tissue like
collagen. Answer: collagen anchors blood vessels to surrounding
tissues and provides structural stability
◉ how do intrinsic factors differ from extrinsic factors in regulating
peripheral resistance. Answer: intrinsic factors regulate local blood
flow based on tissue needs, while extrinsic factors control systemic
vascular tone and arterial pressure
◉ what is blood flow. Answer: the volume of blood passing through
vessels per minute, measured in mL per min
◉ why does a larger pressure gradient increase blood flow. Answer:
a larger pressure difference creates a stronger driving force, pushing
more blood from areas of higher pressure to lower pressure
◉ what role does the lymphatic system play in capillary dynamics.
Answer: the lymphatic system collects excess fluid filtered out of
capillaries and returns it to the bloodstream
,◉ what does high venous compliance mean. Answer: High
"compliance" in veins refers to their ability to expand significantly in
response to small increases in pressure, allowing them to hold large
volumes of blood at low pressure.
◉ which layer in elastic arteries allows them to stretch and recoil.
Answer: tunica media, rich in elastin, enables elastic arteries to
stretch during systole and recoil during diastole
◉ what physiological mechanisms regulate vessel radius to control
vascular resistance dynamically. Answer: vasodilation widens
vessels and lowers resistance while vasoconstriction narrows
vessels and raises resistance
◉ what happens to blood that enters the right atrium from the
inferior vena cava in the fetus. Answer: much of it is directed
through the foramen ovale into the left atrium to supply systemic
circulation
◉ how does boyle's law explain changes in thoracic pressure during
breathing. Answer: boyle's law states that as thoracic volume
increases during inhalation, its pressure decreases, creating a
vacuum effect that aids in venous return
, ◉ what is unique about sinusoidal capillaries, and where are they
located. Answer: have large gaps and a discontinuous basement
membrane, allowing the passage of large molecules like proteins and
blood cells: they are found in the liver, spleen, and bone marrow
◉ what are the types of veins. Answer: postcapillary venules,
muscular venules, medium veins, and large veins
◉ why do precapillary sphincters divert blood flow when closed.
Answer: to prioritize delivery to tissues or organs with higher
metabolic demands, ensuring efficient use of limited blood supply
◉ what makes up the tunica externa. Answer: connective tissue,
including collagen, and may contain an external elastic lamina in
larger arteries
◉ why is vascular resistance important in regulating blood flow.
Answer: resistance can be adjusted through vasoconstriction or
vasodilation, allowing precise control of blood distribution to
different tissues
◉ why do elastic arteries help reduce fluctuations in blood pressure.
Answer: their elasticity allows them to expand during ventricular
contraction and recoil during relaxation, maintaining a more
uniform blood flow
COLLECTION DNA REPLICATION AND PROTEIN
SYNTHESIS MODULE SOLVED ITEMS AND
RESPONSE KEY
◉ why does the tunica externa contain connective tissue like
collagen. Answer: collagen anchors blood vessels to surrounding
tissues and provides structural stability
◉ how do intrinsic factors differ from extrinsic factors in regulating
peripheral resistance. Answer: intrinsic factors regulate local blood
flow based on tissue needs, while extrinsic factors control systemic
vascular tone and arterial pressure
◉ what is blood flow. Answer: the volume of blood passing through
vessels per minute, measured in mL per min
◉ why does a larger pressure gradient increase blood flow. Answer:
a larger pressure difference creates a stronger driving force, pushing
more blood from areas of higher pressure to lower pressure
◉ what role does the lymphatic system play in capillary dynamics.
Answer: the lymphatic system collects excess fluid filtered out of
capillaries and returns it to the bloodstream
,◉ what does high venous compliance mean. Answer: High
"compliance" in veins refers to their ability to expand significantly in
response to small increases in pressure, allowing them to hold large
volumes of blood at low pressure.
◉ which layer in elastic arteries allows them to stretch and recoil.
Answer: tunica media, rich in elastin, enables elastic arteries to
stretch during systole and recoil during diastole
◉ what physiological mechanisms regulate vessel radius to control
vascular resistance dynamically. Answer: vasodilation widens
vessels and lowers resistance while vasoconstriction narrows
vessels and raises resistance
◉ what happens to blood that enters the right atrium from the
inferior vena cava in the fetus. Answer: much of it is directed
through the foramen ovale into the left atrium to supply systemic
circulation
◉ how does boyle's law explain changes in thoracic pressure during
breathing. Answer: boyle's law states that as thoracic volume
increases during inhalation, its pressure decreases, creating a
vacuum effect that aids in venous return
, ◉ what is unique about sinusoidal capillaries, and where are they
located. Answer: have large gaps and a discontinuous basement
membrane, allowing the passage of large molecules like proteins and
blood cells: they are found in the liver, spleen, and bone marrow
◉ what are the types of veins. Answer: postcapillary venules,
muscular venules, medium veins, and large veins
◉ why do precapillary sphincters divert blood flow when closed.
Answer: to prioritize delivery to tissues or organs with higher
metabolic demands, ensuring efficient use of limited blood supply
◉ what makes up the tunica externa. Answer: connective tissue,
including collagen, and may contain an external elastic lamina in
larger arteries
◉ why is vascular resistance important in regulating blood flow.
Answer: resistance can be adjusted through vasoconstriction or
vasodilation, allowing precise control of blood distribution to
different tissues
◉ why do elastic arteries help reduce fluctuations in blood pressure.
Answer: their elasticity allows them to expand during ventricular
contraction and recoil during relaxation, maintaining a more
uniform blood flow
