Biology 235 - Exam 3 Prep Questions With
Verified Answers
Resistance
opposition to blood flow from friction
What is hypertrophy?
increase in muscle size
How does hypertrophy occur?
increase in the number of actin and myosin filaments
satellite cells
protect neuron cell bodies
Blood Flow Resistance
the opposition to blood flow through a vessel
Blood Flow Resistance Factors
Blood Viscosity
Vessel Length
Vessel Radius
Flow rate of blood
F = (pressure gradient / resistance)
or
F = delta_P / R
Effect of radius of blood vessels
friction increases as surface area of contact increases
-more vessel wall in contact with blood
vs
-less contact
Artery
-Contain connective tissue with more elastin
endothelium, elastic tissue, smooth muscle
Arteriole
-where muscle is located, these vessels can respond to SNS or local signals
endothelium, smooth muscle
Capillary
just endothelium
Vein
, -Veins include valves
valve, endothelium, smooth muscle, elastic fibers
Major importance of arteries
serve as a pressure reservoir
-elastic recoil drives flow of blood during diastole
Artery function during systole action
temporarily expand and hold pumped blood
Artery function during diastole action
elastic recoil from artery drives flow of blood
Systole means
Contraction of the heart
-heart squeezes and empties
Diastole means
Relaxation of the heart
-heart relaxes and fills up
How is the amount of blood flowing to organs controlled?
Mean Arterial Pressure
What is the importance of Mean Arterial Pressure (MAP)?
pressure forcing blood into tissues, averaged over cardiac cycle
-driving force for blood flow
Arterioles
control flow to their capillary bed, all together determine peripheral resistance
How is arteriole diameter influenced?
-sympathetic vasoconstriction
-local factors indicating how active they are: high CO2, high H+, cause release of signals from vessel
wall cells (endothelial cells)
-blood does not flow to all capillary beds all the time!
Vasoconstriction
-increases resistance
-increases blood pressure
-increasing MAP upstream
Verified Answers
Resistance
opposition to blood flow from friction
What is hypertrophy?
increase in muscle size
How does hypertrophy occur?
increase in the number of actin and myosin filaments
satellite cells
protect neuron cell bodies
Blood Flow Resistance
the opposition to blood flow through a vessel
Blood Flow Resistance Factors
Blood Viscosity
Vessel Length
Vessel Radius
Flow rate of blood
F = (pressure gradient / resistance)
or
F = delta_P / R
Effect of radius of blood vessels
friction increases as surface area of contact increases
-more vessel wall in contact with blood
vs
-less contact
Artery
-Contain connective tissue with more elastin
endothelium, elastic tissue, smooth muscle
Arteriole
-where muscle is located, these vessels can respond to SNS or local signals
endothelium, smooth muscle
Capillary
just endothelium
Vein
, -Veins include valves
valve, endothelium, smooth muscle, elastic fibers
Major importance of arteries
serve as a pressure reservoir
-elastic recoil drives flow of blood during diastole
Artery function during systole action
temporarily expand and hold pumped blood
Artery function during diastole action
elastic recoil from artery drives flow of blood
Systole means
Contraction of the heart
-heart squeezes and empties
Diastole means
Relaxation of the heart
-heart relaxes and fills up
How is the amount of blood flowing to organs controlled?
Mean Arterial Pressure
What is the importance of Mean Arterial Pressure (MAP)?
pressure forcing blood into tissues, averaged over cardiac cycle
-driving force for blood flow
Arterioles
control flow to their capillary bed, all together determine peripheral resistance
How is arteriole diameter influenced?
-sympathetic vasoconstriction
-local factors indicating how active they are: high CO2, high H+, cause release of signals from vessel
wall cells (endothelial cells)
-blood does not flow to all capillary beds all the time!
Vasoconstriction
-increases resistance
-increases blood pressure
-increasing MAP upstream
