Physiology WK 10.1 Chapter 19 Blood Flow My Lab & Mastering

Suppose that at a given point along a capillary, the following forces exist: capillary hydrostatic pressure (HPc) = 30 mmHg, interstitial fluid hydrostatic pressure (HPif) = 0 mmHg, capillary colloid osmotic pressure (OPc) = 25 mmHg, and interstitial fluid colloid osmotic pressure (OPif) = 2 mmHg. The net filtration pressure at this point in the capillary is __________. 7 mmHg 3 mmHg -3 mmHg -7 mmHg

7 mmHg

Which of the following is NOT a vasoconstrictor? Atrial natriuretic peptide Antidiuretic hormone norepinephrine Angiotensin II

Atrial natriuretic peptide

Which of the following is NOT correct regarding the relationship between pressure, flow, and resistance in the cardiovascular system? -Resistance (R) is more important than the pressure gradient (ΔP) in influencing blood flow to an individual organ. -Blood flow (F) is inversely proportional to the pressure gradient (ΔP) in the blood vessels. -The relationship between resistance (R) and flow (F) is the opposite of the relationship between pressure (ΔP) and flow (F). -Blood flow (F) through the entire circulation equals cardiac output (CO).

Blood flow (F) is inversely proportional to the pressure gradient (ΔP) in the blood vessels.

Select the correct statement about blood flow. It is relatively constant through all body organs. It is greatest where resistance is highest. It is measured in mm Hg. Blood flow through the entire vascular system is proportional to cardiac output.

Blood flow through the entire vascular system is proportional to cardiac output.

Which of the following statements describes the significance of blood pressure changes as blood reaches the capillary beds? Blood pressure increases as it reaches the capillary beds because capillaries need a higher blood pressure for filtration activities. Blood pressure drops as it reaches the capillary beds because capillaries depend on the lower pressure to prevent fluid exchange between the capillaries and interstitial space. Blood pressure does not change as blood flows from arteries into capillaries. Blood pressure drops as it reaches the capillary beds because high pressure would rupture them.

Blood pressure drops as it reaches the capillary beds because high pressure would rupture them.

Which of the following is most likely to occur in the arteriovenous shunts present in the blood vessels of the finger tips and toes? Warmer temperatures will result in vasoconstriction in the arteriovenous shunts. Colder temperatures will result in vasoconstriction in the arteriovenous shunts. Colder temperatures will result in vasodilation in the arteriovenous shunts. Exercise will result in vasoconstriction in the arteriovenous shunts.

Colder temperatures will result in vasoconstriction in the arteriovenous shunts.

Which of the following would NOT be a cause of edema in your patient's lower extremities? Congestive heart failure Sitting during a long flight Pregnancy Excess protein in the diet

Excess protein in the diet

Osmotic pressure is created by the presence in a fluid of small diffusible molecules that easily move through the capillary wall. True False

False

The velocity of blood is slowest in the capillaries and pressure of blood is lowest in the veins. Which of the following is NOT an accurate description of the benefits of slow, low pressure blood in the capillary beds? Lower pressure reduces the chance of injury to delicate capillary vessels. Lower pressure on the venous end of the capillary bed allows for greater reabsorption of fluid back to the plasma. Lower pressure in the capillary bed helps to increase pressure in the venous circulation. Slower blood flow through capillaries allows more time for diffusion to take place in the capillary bed.

Lower pressure in the capillary bed helps to increase pressure in the venous circulation.

Which of the choices below explains why the arterioles are known as resistance vessels? Their prime function is the exchange of nutrients and wastes between the blood and tissue cells. They distribute blood to various parts of the body. The contraction and relaxation of the smooth muscle in their walls can change their diameter. They contain a large quantity of elastic tissue.

The contraction and relaxation of the smooth muscle in their walls can change their diameter.

Which of the following statements does NOT correctly describe tissue perfusion in the cardiovascular system? Accumulation of local metabolites triggering dilation of arterioles is an example of intrinsic control of tissue perfusion. Autonomic nervous system regulation of blood pressure is an example of extrinsic control of tissue perfusion. The myogenic response is an example of extrinsic control of tissue perfusion. Perfusion of the kidneys is important for urine formation.

The myogenic response is an example of extrinsic control of tissue perfusion.

An increase in blood viscosity will cause an increase in total peripheral resistance. True False

True

Edema can be caused by an increase in capillary hydrostatic pressure (HPc) or a decrease in capillary colloid osmotic pressure (OPc). True False

True

Osmotic pressure is fairly constant along the entire length of a capillary bed. True False

True

The adjustment of blood flow to each tissue in proportion to its requirements at any point in time is termed autoregulation. True False

True

Whereas diffusion is more important for solute exchange between plasma and interstitial fluid, bulk flow is more important for regulation of the relative volumes of blood and interstitial fluid. True False

True

Which of the following would NOT result in the dilation of the feeder arterioles and opening of the precapillary sphincters in systemic capillary beds? a local increase in pH an increase in local tissue carbon dioxide a decrease in local tissue oxygen content a local increase in histamine

a local increase in pH

Which of the following is the most significant source of blood flow resistance? blood vessel diameter blood viscosity blood vessels type total blood vessel length

blood vessel diameter

Which of the following is not a capillary transport mechanism that allows for the exchange of nutrients and gases? transport in pinocytotic vesicles. diffusion through the endothelial cell membrane movement through intracellular clefts or fenestrations bulk flow

bulk flow

Reduction in the concentration of albumin in blood plasma would alter capillary exchange by ________. decreasing colloid osmotic pressure and edema will occur decreasing colloid osmotic pressure and blood volume, blood pressure increases increasing hydrostatic pressure and edema will occur increasing hydrostatic pressure and blood volume, blood pressure increases

decreasing colloid osmotic pressure and edema will occur

Which of the following would decrease total peripheral resistance to blood flow? vasoconstriction decreasing the hematocrit increasing blood vessel length atherosclerosis

decreasing the hematocrit

Blood flow is ________ proportional to the difference in blood pressure. Blood flow is ________ proportional to the total peripheral resistance. inversely; directly directly; directly inversely; inversely directly; inversely

directly; inversely

Which of the following intrinsic mechanisms (autoregulation) for controlling arteriolar smooth muscle diameter promotes vasoconstriction? nitrous oxide endothelins histamine prostaglandins

endothelins

Arteriolar blood pressure increases in response to all but which of the following? increasing stroke volume increasing heart rate falling blood volume rising blood volume all of these

falling blood volume

Which of the choices below reflects the balance (or imbalance) between the direction and amount of fluid that flows across the capillary walls? blood volume and viscosity plasma and formed element concentration hydrostatic and osmotic pressure hydrostatic pressure only

hydrostatic and osmotic pressure

In general, it is expected that ________. hydrostatic pressure will rise as blood moves away from the arteriole end of the capillary bed osmotic pressure will be lower in the arteriole end of the capillary bed compared to the venous end hydrostatic pressure will drop as blood moves away from the arteriole end of the capillary bed hydrostatic pressure will remain constant throughout the capillary bed

hydrostatic pressure will drop as blood moves away from the arteriole end of the capillary bed

A muscle that is being regularly contracted during exercise will attract blood flow by dilating arterioles. Which of these factors would contribute to this effect? heat loss from the muscle an increase in sympathetic tone increased levels of carbon dioxide increased levels of oxygen

increased levels of carbon dioxide

Blood flow to the skin ________. increases when body temperature drops so that the skin does not freeze increases when environmental temperature rises is not an important source of nutrients and oxygen for skin cells is controlled mainly by decreasing pH

increases when body temperature drops so that the skin does not freeze

Cerebral blood flow is regulated by ________. ADH intrinsic autoregulatory mechanisms the hypothalamic "thermostat" skin temperature

intrinsic autoregulatory mechanisms

Brain blood flow autoregulation ________. is controlled by cardiac centers in the pons causes constriction of cerebral blood vessels in response to a drop in systemic blood pressure is abolished when abnormally high CO2 levels persist is less sensitive to pH than to a decreased oxygen level

is abolished when abnormally high CO2 levels persist

Which of the following organs would experience decreased blood flow during exercise? skin brain skeletal muscles kidneys

kidneys

In local autoregulation of blood flow, usually low oxygen levels cause vasodilation. Which tissue shows the opposite pattern? lungs liver heart skeletal muscles

lungs

Where in the body would you find low oxygen levels causing vasoconstriction and high levels causing vasodilation? kidney heart liver lungs

lungs

What pressure is responsible for reabsorption and for pulling fluids into the venous end of capillaries? hydrostatic pressure in interstitial fluid (HPif) osmotic pressure in interstitial fluid (OPif) hydrostatic pressure in a capillary (HPc) osmotic pressure in capillary (OPc)

osmotic pressure in capillary (OPc)

Which of the following is an INCORRECT statement regarding pressure conditions in a capillary as blood moves through it from the arteriole end to the venous end? osmotic pressure in the capillary (OPc) drops interstitial hydrostatic pressure does not play a significant role in capillary pressures net filtration pressure drops blood hydrostatic pressure (HPc) drops

osmotic pressure in the capillary (OPc) drops

In general, it is expected that ________. osmotic pressure will remain relatively consistent throughout the capillary bed osmotic pressure will be higher in the arteriole end of the capillary bed compared to the venous end hydrostatic pressure will remain constant throughout the capillary bed osmotic pressure will be lower in the arteriole end of the capillary bed compared to the venous end

osmotic pressure will remain relatively consistent throughout the capillary bed

Which of the following CANNOT diffuse across a capillary wall to or from the surrounding interstitial fluid? proteins lipid-soluble substances monosaccharides and amino acids oxygen and carbon dioxide

proteins

The influence of blood vessel diameter on total peripheral resistance is ________. insignificant because vessel diameter does not vary significant because resistance is directly proportional to the blood vessel diameter significant because resistance is inversely proportional to the fourth power of the vessel radius the only factor that influences resistance

significant because resistance is inversely proportional to the fourth power of the vessel radius

The velocity of blood flow is ________. slower in the veins than in the capillaries because veins have a large diameter in direct proportion to the total cross-sectional area of the blood vessels slower in the arteries than in capillaries because arteries possess a relatively large diameter slowest in the capillaries because the total cross-sectional area is the greatest

slowest in the capillaries because the total cross-sectional area is the greatest

Which of the following is a myogenic factor that influences blood flow? atrial natriuretic peptide epinephrine from the adrenal medulla sympathetic tone stretch of vascular smooth muscle

stretch of vascular smooth muscle

Which of the following would not normally be a direct cause of edema? hypoproteinemia in a person with liver disease increased leakage of plasma proteins across capillary walls into the interstitial space tachycardia reduced ability to drain interstitial fluid into lymphatic vessels

tachycardia

Which of the following is NOT an important source of resistance to blood flow? blood viscosity total blood volume vessel length vessel diameter

total blood volume

Which structural layer of blood vessels is most responsible for maintaining blood pressure? subendothelial tunica externa tunica media tunica intima

tunica media

Assume a person is experiencing a hemorrhage and the HPc has dropped to 23 mm Hg at the arteriole end of the capillary. Calculate net filtration pressure (NFP) at the arteriole end of the capillary. −8 mm Hg −2 mm Hg 2 mm Hg 10 mm Hg

−2 mm Hg