chapter 19
tunica intima
-endothelial layer that lines all vessels and continuous with the endothelium of the heart -smooth slick inner layer that repels blood and platelets -nitric oxide and prostacyclin both relax blood vessels and inhibit platelet activation
Which flow tube length had the greatest flow rate?
10 mm
Which of the following changes would produce the greatest change in total peripheral resistance? -10% --change in blood viscosity -10% change in vessel length -10% change in vessel diameter -10% change in cardiac output
10% change in vessel diameter
cardiac output
The volume of blood ejected from the left side(ventricle) of the heart in one minute.
Which of the following is NOT one of the ways that angiotensin II increases arterial blood pressure? -Angiotensin II prompts the release of antidiuretic hormone (ADH). -Angiotensin II stimulates the secretion of aldosterone. -Angiotensin II promotes vasodilation that decreases peripheral resistance. -Angiotensin II triggers the sensation of thirst.
Angiotensin II promotes vasodilation that decreases peripheral resistance. Angiotensin II actually promotes vasoconstriction, which decreases circulatory volume and raises mean arterial blood pressure.
Which of the following is NOT correct regarding the relationship between pressure, flow, and resistance in the cardiovascular system? Blood flow is inversely proportional to the change in pressure in the blood vessels. Blood flow equals cardiac output. The relationship between resistance and flow is the opposite of the relationship between pressure and flow. Instead of resistance affecting systemic circulation, most of the time resistance is used to change flow to individual organs.
Blood flow is inversely proportional to the change in pressure in the blood vessels.
Select the correct statement about blood flow.
Blood flow through the entire vascular system is equal to the cardiac output.
How would an attack by a mugger affect blood pressure? What is the physiological basis for your answer?
Blood pressure would increase due to sympathetic nervous system stimulation.
What is the effect of hypovolemic shock on the blood vessels and the heart?
Blood vessels constrict to increase venous return and maintain pressure. Heart rate increases to compensate for loss of blood pressure and to maintain cardiac output.
Which of the following is likely during vigorous exercise? -Blood flow to the kidneys increases. -Blood will be diverted to the digestive organs. -Capillaries of the active muscles will be engorged with blood. -The skin will be cold and clammy.
Capillaries of the active muscles will be engorged with blood.
What would be the effect of a high salt diet on blood pressure? What is the physiological basis for your answer?
Increased blood pressure. This is due to increased sodium in the blood, increasing the plasma volume.
Which of the following best describes the benefit of the vasomotion process?
It provides a balance between adequate perfusion to all of the tissues while maintaining blood's pressure.
Each of the following describes the action of aldosterone except one. Which of the following does not describe the activity of aldosterone hormone? -It promotes an increase in blood pressure. -It promotes an increase in sodium reabsorption from the kidney to the blood. -It will result in higher sodium levels in the urine. -It will reduce urine output.
It will result in higher sodium levels in the urine.
Which of the choices below does not explain why low capillary pressures are desirable?
Low blood pressure is associated with longer life span than high blood pressure.
all vessels consist of a
Lumen
blood pressure
Pressure exerted by the blood upon the walls of the blood vessels, especially arteries, usually measured by means of a sphygmomanometer at the brachial artery and expressed in millimeters of mercury.
Which of the choices below explains why the arterioles are known as resistance vessels?
The contraction and relaxation of the smooth muscle in their walls can change their diameter.
Which of the following statements is not true of the precapillary sphincters? They regulate the flow of blood to tissues served by the true capillaries. They allow blood to bypass the true capillaries that are fed by the metarteriole. They decrease the osmotic pressure in the thoroughfare channel. They increase or decrease rates of perfusion to the tissues served by the true capillaries.
They decrease the osmotic pressure in the thoroughfare channel.
Continuous capillaries are the most common capillaries in the body. T or F
True
The adjustment of blood flow to each tissue in proportion to its requirements at any point in time is termed autoregulation. true or false?
True
Walls of all vessels, except capillaries, have 3 layers or tunics___
Tunica intima (interna) Tunica media tunica externa
Which of the following would decrease peripheral resistance to blood flow?
anemia
Site where resistance to blood flow is greatest.
arterioles
What blood vessel experiences the steepest drop in blood pressure?
arterioles
minor types of vessels are
arterioles and venues
During a marathon which of the following hormones is least likely to be released by the runner?
atrial natriuretic peptide (ANP)
Which of the following will lower blood pressure?
atrial natriuretic peptide (ANP)
Why is it important that blood pressure drop to lower levels as it reaches the capillary beds?
because capillaries are fragile and extremely permeable
Blood pressure would INCREASE as a result of a DECREASE in __________.
blood vessel diameter
Which of the following has the greatest effect on blood flow? -Blood vessel radius, viscosity and blood vessel length all have an equal effect. -viscosity -blood vessel length -blood vessel radius
blood vessel radius
At what point would we definitely NOT be able to measure the difference between systolic, diastolic, and mean arterial pressure?
capillaries
Permitting the exchange of nutrients and gases between the blood and tissue cells is the primary function of ________.
capillaries
Site where exchanges of food and gases are made
capillaries
Site where the velocity of blood flow is slowest
capillaries
What type of vessel is capable of allowing the passage of gases and nutrients though its walls to nourish surrounding tissue?
capillaries
What vessels sustain a drop in pressure from approximately 35 mm Hg to around 17 mm Hg?
capillaries
Which of the following is not true regarding fenestrated capillaries? capillaries form the blood-brain barrier. Fenestrated capillaries in endocrine organs allow hormones rapid entry into the blood. Fenestrated capillaries are essential for filtration of blood plasma in the kidney. Fenestrated capillaries in the small intestine receive nutrients from digested food.
capillaries form the blood-brain barrier.
Results from heart inability to sustain adequate circulation due to myocardial
cariogenic shock
arteries
carry blood away from the hear; oxygenated except for pulmonary circulation and umbilical vessels of fetus
veins
carry blood towards the heart; deoxygenated except for pulmonary circulation and umbilical vessels of fetus
The baroreceptors in the carotid sinus and aortic arch are sensitive to which of the following? -a decrease in oxygen levels -changes in arterial pressure -a decrease in carbon dioxide -an increase in oxygen levels
changes in arterial pressure
Vasomotion because of changes in pH or CO2 levels would be a result of __________?
chemoreceptor reflexes
Due to inadequate blood flow to meet tissue needs
circulatory shock
Which of the following would be interrupted in the indirect renal mechanism if angiotensin converting enzyme (ACE) is blocked from performing its job?
conversion of angiotensin I into angiotensin II
Increasing blood vessel length _______.
has the same effect as decreasing blood vessel radius and increases resistance to flow
Due to large-scale blood loss
hypovolemic shock
Which of these responses is NOT a response consistent with a drop in mean arterial pressure? -increased thirst -increased filtration by the kidneys -release of renin from the kidneys -secretion of aldosterone
increased filtration by the kidneys. A drop in blood pressure tends to decrease filtration by the kidneys, which precipitates a reduction in urine formation.
A muscle that is being regularly contracted during exercise will attract blood flow by dilating arterioles. Which of these factors would contribute to the effect?--an increase in sympathetic tone -heat loss from the muscle -increased levels of carbon dioxide -increased levels of oxygen
increased levels of carbon dioxide
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
Site where the blood pressure is greatest
large arteries
Site where the velocity of blood flow is fastest
large arteries
Site where blood pressure is lowest
large veins
Site where the blood volume is greatest
large veins
Which of the following is characteristic of veins but not arteries?
larger internal diameter
A person suddenly gaining significant amounts of adipose tissue can expect all of the following physiological changes except one. Which of the following is least likely to occur with a sudden and significant gain in adipose tissue? -higher peripheral resistance and higher blood pressure -increased risk of developing atherosclerosis -lower heart rate and reduced blood flow -increased angiogenesis and higher peripheral resistance
lower heart rate and reduced blood flow
What type of vessel has a relatively large amount of smooth muscle compared to its elastic tissue?
muscular artery
tunica externa
outer layer of a blood vessel which connects it to surrounding tissues composed mostly of loose collagen fibers
what has fluence on blood pressure?
peripheral resistance cardiac output blood volume
osmotic pressure
pressure that must be applied to prevent osmotic movement across a selectively permeable membrane
Which of the following would NOT move by diffusion across a capillary endothelium to or from the surrounding interstitial fluid and tissues? oxygen proteins lipid-soluble substances carbon dioxide
proteins
blood vessels can
pulsate, constrict, dilate, and proliferate
tunica media
regulated by sympathetic nervous system. controls vasoconstriction and vasodilation. Important in maintaining blood pressure and continuous blood circulation (flow). Has Elastin
Which of the following is involved in long-term regulation of blood pressure? -adrenal epinephrine release -chemoreceptor reflexes -renal mechanisms -carotid sinus baroreceptors
renal mechanisms
Which of the following would take the longest time to regulate blood pressure? -renal regulation -chemoreceptor-initiated reflexes -hormonal control of peripheral resistance -baroreceptor-initiated reflexes
renal regulation
In red bone marrow newly formed blood cells enter the circulation. You would expect to see many ________ type of capillaries in red bone marrow.
sinusoid capillaries
The most permeable capillaries, which contain fenestrations and large intercellular clefts, are __________.
sinusoid capillaries
The velocity of blood flow is
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?
stretch of vascular smooth muscle
Mechanisms that do not help regulate blood pressure include ________.
the dural sinus reflex
blood viscosity
the friction red blood cells encounter when moving past each other. or thickness of blood
total peripheral resistance
the total resistance to flow generated by all the capillary beds in systemic circulation
What is the relationship between fluid flow and flow tube length?
they are inversely proportional to each other
Which of the following describes why the body might need to increase vessel length?
to accommodate weight gain and height changes
Which layer of the typical blood vessel is constructed from simple squamous epithelium?
tunica intima
Which layer of the typical vessel can be regulated to constrict or dilate the lumen?
tunica media
Which tunic of an artery is most responsible for maintaining blood pressure and continuous blood circulation?
tunica media
Factors that aid venous return include all except ________. activity of skeletal muscles venous valves urinary output pressure changes in the thorax
urinary output
Normal blood volume but poor circulation due to extreme vasodilation
vascular shock
How does the body decrease the blood vessel radius?
vasoconstriction
Laminar flow of the blood is achieved through _______.
vasodilation
Which vessels carry blood toward the heart?
veins
the three major types of vessels are
Arteries, capillaries and veins
Due to the branching of arteries the type of arteries that would be most numerous would be ________.
Arterioles
.Site that is the major determinant of peripheral resistance.
Arterioles:
Arteries are divided into three groups
!. Elastic (conducting) arteries 2.Muscular (distributing) arteries 3.Arterioles (resistance) arteries
Calculate the mean arterial pressure (MAP) for a patient whose systolic blood pressure is 120 mm Hg and diastolic blood pressure is 70 mm Hg.
87 mm Hg. Mean arterial pressure (MAP) is calculated by dividing the pulse pressure by three and adding the result to the diastolic pressure. The pulse pressure is the difference between the systolic and diastolic pressures.
A pregnant patient comes into a clinic and asks about a small dark bulge that is becoming more apparent on her leg. What is it and what caused it?
A varicose vein. The growing fetus puts downward pressure on the vessels of the groin and restricts the return of blood to the heart, causing the valves in the peripheral veins to begin to fail.
How would a blow to the head that damages (disables) the vasomotor center affect blood pressure? What is the physiological basis for your answer?
Damage to the vasomotor center will cause a loss of vasomotor tone and a drop in blood pressure, because the vasomotor center is the integrating center for blood pressure control.
Decreased output from the vasomotor center allows arterioles and veins to constrict. True or False
False Decreased output from the vasomotor center allows arterioles and veins to dilate.
When the radius of the flow tube is decreased, the _______.
fluid flow rate decreases
A patient with essential hypertension might have pressures of 200/120 mm Hg. This hypertensive state could result in all of the following changes except ________. -increased work of the left ventricle -increased damage to blood vessel endothelium -increased incidence of coronary artery disease -decreased size of the heart muscle
decreased size of the heart muscle
Reduction in the concentration of albumin in blood plasma would alter capillary exchange by ________.
decreasing colloid osmotic pressure and edema will occur
blood vessels
delivery system of dynamic structures that begins and ends at the heart
During exercise, we might expect blood vessels in the skeletal muscle to be somewhat _______________ and the blood vessels in the digestive organs to be somewhat ____________.
dilated, constricted
capillaries
direct contact with tissue cells and directly serve cellular needs
Large diameter, thick-walled arteries that are close to the heart and act as pressure reservoirs would be __________.
elastic arteries
Which type of vessel is most suited to expanding and recoiling in response to the ejection of blood from the heart?
elastic artery
Arteriolar blood pressure increases in response to all but which of the following? -falling blood volume -increasing stroke volume -rising blood volume -increasing heart rate
falling blood volume
The thick-walled arteries close to the heart are called muscular arteries.
false
Vasodilation is a widening of the lumen due to smooth muscle contraction. true or false?
false
