BIO HW CH 19

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

blood vessel diameter

Gas and nutrient exchanges between the blood and tissues take place at the __________. -arterioles -veins -capillaries -arteries

capillaries

Site where exchanges of food and gases are made. -Capillaries -Arterioles -Large veins -Large arteries

capillaries

Site where the velocity of blood flow is slowest. -Capillaries -Arterioles -Large veins -Large arteries

capillaries

What vessels sustain a drop in pressure from approximately 35 mm Hg to around 17 mm Hg?

capillaries

Large diameter, thick-walled arteries that are close to the heart and act as pressure reservoirs would be __________. -elastic arteries -arterioles -muscular arteries -veins

elastic arteries

Site where the blood pressure is greatest. -Capillaries -Arterioles -Large veins -Large arteries

large arteries

Site where the velocity of blood flow is fastest. -Capillaries -Arterioles -Large veins -Large arteries

large arteries

Site where blood pressure is lowest. -Capillaries -Arterioles -Large veins -Large arteries

large veins

Site where the blood volume is greatest -Capillaries -Arterioles -Large veins -Large arteries

large veins

Which of the following processes provides a long-term response to changes in blood pressure? -renal regulation -neural controls -baroreceptor-initiated reflexes -chemoreceptor-initiated reflexes

renal regulation

The velocity of blood flow is ________. -slower in the veins than in the capillaries because veins have a large diameter -slowest in the capillaries because the total cross-sectional area is the greatest -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 diamete

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

Continuous capillaries are the most common capillaries in the body. 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 layer of the typical blood vessel is constructed from simple squamous epithelium? -tunica intima -tunica media -tunica externa

tunica intima

Which layer of the typical vessel can be regulated to constrict or dilate the lumen? -tunica externa -tunica intima -tunica media -vasa vasorum

tunica media

What type of vessel has relatively little smooth muscle or elastin in the tunica media, a large lumen (average of 5.0 mm in diameter), and thin walls (average of 0.5 mm)? -venule -arteriole -vein -muscular artery

vein

Which of the following is NOT one of the four ways in which angiotensin II works to increase arterial blood pressure and extracellular fluid volume? -Angiotensin II prompts the release of antidiuretic hormone (ADH). -Angiotensin II stimulates the secretion of aldosterone. -Angiotensin II triggers the sensation of thirst. -Angiotensin II promotes vasodilation that decreases peripheral resistance

-Angiotensin II promotes vasodilation that decreases peripheral resistance

Why is it important that blood pressure drop to lower levels as it reaches the capillary beds? -Because capillaries depend on the lower pressure to prevent fluid exchange between the capillaries and the tissue fluid. -Because capillaries are fragile and extremely permeable. -Because capillaries actually need a higher blood pressure for filtration activities. -Because capillaries actually are high-pressure vessels

-Because capillaries are fragile and extremely permeable.

How would an attack by a mugger affect blood pressure? What is the physiological basis for your answer? -Blood pressure would increase due to vagal nerve stimulation. -Blood pressure would increase due to sympathetic nervous system stimulation. -Blood pressure would decrease due to sympathetic nervous system stimulation. -Blood pressure would decrease due to parasympathetic nervous system stimulation. -Blood pressure would increase due to parasympathetic nervous system stimulation.

-Blood pressure would increase due to sympathetic nervous system stimulation.

Select the correct statement about factors that influence blood pressure. -Systemic vasodilation would increase blood pressure, due to diversion of blood to essential areas. -an increase in cardiac output corresponds to a decrease in blood pressure, due to the increased delivery. -Excess protein production would decrease blood pressure. -Excess red cell production would cause a blood pressure increase.

-Excess red cell production would cause a blood pressure increase.

Which of the following is not true regarding fenestrated capillaries? -Fenestrated capillaries in the small intestine receive nutrients from digested food. -Fenestrated capillaries are essential for filtration of blood plasma in the kidney. -Fenestrated capillaries form the blood-brain barrier. -Fenestrated capillaries in endocrine organs allow hormones rapid entry into the blood.

-Fenestrated capillaries form the blood-brain barrier.

What would be the effect of a high salt diet on blood pressure? What is the physiological basis for your answer? -Decreased blood pressure. This is due to increased sodium in the blood, triggering sodium receptors in the vasomotor center to decrease sympathetic stimulation of blood vessels. -Decreased blood pressure. This is due to increased sodium in the blood, increasing the plasma volume. -Increased blood pressure. This is due to increased sodium in the blood, triggering sodium receptors in the vasomotor center to increase sympathetic stimulation of blood vessels. -Increased blood pressure. This is due to increased sodium in the blood, increasing the plasma volume.

-Increased blood pressure. This is due to increased sodium in the blood, increasing the plasma volume.

Which of the following is true about veins? -Up to 35% of total body blood is in venous circulation at any given time. -Venous valves are formed from the tunica media. -Veins are called capacitance vessels or blood reservoirs. -Veins have a small lumen in relation to the thickness of the vessel wall.

-Veins are called capacitance vessels or blood reservoirs.

Which of the following is true about veins? -Veins have a smaller diameter lumen than arteries. -Veins have valves; arteries do not. -Veins carry blood away from the heart, while arteries carry blood to the heart. -Veins are more muscular than arteries.

-Veins have valves; arteries do not.

The baroreceptors in the carotid sinus and aortic arch are sensitive to which of the following? -a decrease in carbon dioxide -an increase in oxygen levels -changes in arterial pressure -a decrease in oxygen levels

-changes in arterial pressure

What type of tissue is found in the walls of the arteries but not in the walls of capillaries and venules? -collagen fibers -endothelium -elastic tissue -smooth muscle

-elastic tissue

If a person stands up suddenly from the prone (lying) position they may feel a sudden dizzy or lightheadedness. Which of the following is the least likely physiological response to this situation? -increased parasympathetic nerve impulses to the heart -increasing peripheral resistance due to vasoconstriction -faster heart rate and greater heart contractility -increased sympathetic output to the heart

-increased parasympathetic nerve impulses to the heart

Peripheral resistance ________. -is not a major factor in blood pressure in healthy individuals -decreases with increasing length of the blood vessel -increases as blood vessel diameter increases -increases as blood viscosity increases

-increases as blood viscosity increases

In the dynamics of blood flow through capillaries, hydrostatic pressure ________. -is completely canceled out by osmotic pressure -is the same as capillary blood pressure -generally forces fluid from the interstitial space into the capillaries -and osmotic pressure are the same

-is the same as capillary blood pressure

The arteries that are also called distributing arteries are the ________. -capillaries -arterioles -elastic arteries -muscular arteries

-muscular arteries

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

-osmotic pressure in capillary (OPc)

Which tunic of an artery is most responsible for maintaining blood pressure and continuous blood circulation? -tunica adventitia -tunica media -tunica intima -tunica externa

-tunica media

Site where resistance to blood flow is greatest. -Capillaries -Arterioles -Large veins -Large arteries

Arterioles

The short-term controls of blood pressure, mediated by the nervous system and bloodborne chemicals, primarily operate via all but which of the following? -reflex arcs associated with vasomotor fibers -chemoreceptors -reflex arcs involving baroreceptors -altering blood volume

altering blood volume

Which of the following would decrease peripheral resistance to blood flow? -vasoconstriction -increasing blood vessel length -anemia -atherosclerosis

anemia

Site that is the major determinant of peripheral resistance. -Capillaries -Arterioles -Large veins -Large arteries

arterioles