What is the outermost layer of the blood vessel wall for an artery or vein?

tunica externa

The aorta is an example of a(n) __________.

elastic artery

Which tunic of an artery is most responsible for maintaining blood pressure and continuous blood circulation?

tunica media

Histologically, the ________ is squamous epithelium supported by a sparse connective tissue layer.

tunica intima

Vasodilation is a widening of the lumen due to smooth muscle contraction.

F

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

F

The outermost layer of a blood vessel is the tunica intima.

F

Which type of vessel contains elastin in all three tunics to allow the vessel to expand and recoil as the heart ejects blood?

elastic artery

What type of vessel has relatively more smooth muscle and less elastic tissue?

muscular artery

Gas and nutrient exchanges between the blood and tissues take place at the __________.

capillaries

What type of tissue is found in the walls of the arteries that leave the heart but not in the walls of the large veins that enter the heart?

elastic tissue

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 statement best describes arteries?

All carry blood away from the heart.

The arteries that directly feed into the capillary beds are called ________.

arterioles

The arteries that are also called distributing arteries are the ________.

muscular arteries

The thick-walled arteries close to the heart are called muscular arteries.

F

Leaky capillaries found in the bone marrow are called __________.

sinusoidal capillaries

Which of the following is true about veins?

Veins have valves; arteries do not.

Which capillaries are the most common in the body?

continuous capillaries

Which of the following is not true regarding fenestrated capillaries?

Fenestrated capillaries form the blood-brain barrier.

Modified capillaries that are lined with phagocytes are called ________.

sinusoids

The most common type of blood capillary is the ________.

continuous capillary

Permitting the exchange of nutrients and gases between the blood and tissue cells is the primary function of ________.

capillaries

A precapillary sphincter is a cuff of smooth muscle that regulates the flow of blood into the capillaries.

T

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)?

vein

__________ is the pressure that propels blood to the tissues.

Mean arterial pressure

Varicose veins seen in the superficial veins of the legs are unsightly and often treated by surgically removing them. However, even without these veins being present, the return of all blood toward the heart from the legs is not diminished primarily because ______.

blood can still return via the deep veins

Which of the following is true about veins?

Veins are called capacitance vessels or blood reservoirs.

The pancreas is an example of an organ with arteries that do not anastomose.

F

Arteries supplying the same territory are often merged with one another, forming arterial anastomoses.

T

Which of the following will lower blood pressure?

atrial natriuretic peptide (ANP)

Which of the following is NOT an important source of resistance to blood flow?

total blood volume

Peripheral resistance ________.

increases as blood viscosity increases

The influence of blood vessel diameter on peripheral resistance is ________.

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

Which of the following is the most significant source of blood flow resistance?

blood vessel diameter

Select the correct statement about blood flow.

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

An increase in blood viscosity will cause an increase in peripheral resistance.

T

Calculate mean arterial pressure (MAP) if systolic blood pressure is 120 mm Hg and diastolic blood pressure is 70 mm Hg.

87 mm Hg

What blood vessel experiences the steepest drop in blood pressure?

arterioles

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

capillaries

Which of the following is involved in long-term blood pressure regulation?

renal mechanisms

Why is it important that blood pressure drop to lower levels as it reaches the capillary beds?

Because capillaries are fragile and extremely permeable.

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.

Factors that aid venous return include all except ________.

urinary output

Select the correct statement about factors that influence blood pressure.

Excess red cell production would cause a blood pressure increase.

Arteriolar blood pressure increases in response to all but which of the following?

falling blood volume

The pulse pressure is ________.

systolic pressure minus diastolic pressure

Where are the sensors for the arterial baroreceptor reflex located?

carotid sinus and aortic arch

If blood pressure is increased at the arterial baroreceptors, what would happen with the activity level of the parasympathetic nervous system (PNS) and sympathetic nervous system (SNS)?

increased PNS and SNS activity

Which of the following would cause vasodilation of arterioles?

decreased activity of the sympathetic nervous system

Stimulation of the adrenal medulla would result in which of the following?

an increase in heart rate and contractility

A decrease in blood pressure at the arterial baroreceptors would result in which of the following?

an increase in heart contractility

Which action of the indirect renal mechanism promotes sodium reabsorption by the kidneys to increase mean arterial pressure?

aldosterone

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 promotes vasodilation that decreases peripheral resistance.

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

Which of the following would experience a decreased blood flow during exercise?

kidneys

Which of the following would NOT move by diffusion across a capillary endothelium to or from the surrounding interstitial fluid and tissues?

proteins

Which of the following is a stimulus in local autoregulation of blood flow?

nitric oxide

Which of the following is a long-term mechanism for maintaining blood pressure?

renal regulation

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.

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 total extracellular fluid volume.

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.

How would an attack by a mugger effect blood pressure? What is the physiological basis for your answer?

Blood pressure would increase due to sympathetic nervous system stimulation.

Mr. Wilson is a 45-year-old stockbroker with essential hypertension. He is African American, obese, and he smokes 2-3 packs of cigarettes daily. What risk factors for hypertension are typified by Mr. Wilson? What complications are likely if corrective steps are not taken?

The risk factors are obesity, race, a high-stress job, and smoking. Complications could include atherosclerosis, heart failure, renal failure, and stroke.

Which of the following is not one of the three main factors influencing blood pressure?

emotional state

Which of the following processes provides a long-term response to changes in blood pressure?

renal regulation

Which of the following chemicals does not help regulate blood pressure?

nitric acid

Which of the following do not influence arterial pulse rate?

the vessel selected to palpate

Which of the following blood pressure readings would be indicative of hypertension?

170/96 in a 50-year-old man

Mechanisms that do not help regulate blood pressure include ________.

the dural sinus reflex

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 ________.

decreased size of the heart muscle

The short-term controls of blood pressure, mediated by the nervous system and bloodborne chemicals, primarily operate via all but which of the following?

altering blood volume

Secondary hypertension can be caused by ________.

arteriosclerosis

The baroreceptors in the carotid sinus and aortic arch are sensitive to which of the following?

changes in arterial pressure

Aldosterone will ________.

promote an increase in blood pressure

Hypotension is generally considered systolic blood pressure that is below 100 mm Hg.

T

The carotid sinus reflex protects the blood supply to the brain, whereas the aortic reflex is more concerned with maintaining adequate blood pressure in the systemic circuit as a whole.

T

During exercise, cardiac output may increase by more than 170% to meet the body’s increased O2demands. This increase in cardiac output increases blood pressure. But the accompanying increase in arterial pressure is relatively small—only about 40%. What limits this increase in blood pressure so that it doesn’t reach dangerously high levels during exercise?

Vasodilation causes arterial diameter to increase in the exercising skeletal muscle.

Blood pressure would INCREASE as a result of a DECREASE in __________.

blood vessel diameter

Which of the following changes would produce the greatest change in total peripheral resistance?

10% change in vessel diameter

In the capillaries, hydrostatic pressure (HP) is exerted by __________.

blood pressure

The net hydrostatic pressure (HP) is the hydrostatic pressure in the __________ minus hydrostatic pressure in the __________.

capillary; interstitial fluid

Which of the following would reflect the typical net hydrostatic pressure (HP) at the arterial end of the capillary?

34 mm Hg

The colloid osmotic pressure in the capillary is caused by __________.

proteins in the blood

Which net pressure draws fluid into the capillary?

net osmotic pressure

Reabsorption of fluid into the capillary takes place at the arterial end or venous end of the capillary?

venous

Which of the following is a metabolic factor that influences blood flow?

low oxygen levels

Which of the following promotes vasodilation?

nitric oxide

Which of the following intrinsic mechanisms (autoregulation) for controlling arteriolar smooth muscle diameter promotes vasoconstriction?

endothelins

What pressure is responsible for reabsorption and for pulling fluids into the venous end of capillaries?

osmotic pressure in capillary (OP_c)

What is the value for the net filtration pressure (NFP) at the arteriolar end of the capillary?

10 mm Hg

Assume a person is experiencing a hemorrhage and the HP_c 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.

-2 mm Hg

Which of the following would be a result of anaphylaxis (a systemic allergic reaction)?

vascular shock

Blood from the lower limbs is returned to the heart via the __________.

inferior vena cava

The inferior vena cava carries blood __________ the __________ of the heart.

to; right atrium

Substances absorbed in the intestines would be routed to the liver via the __________.

hepatic portal vein

Vasodilation will result in increased blood flow to a given tissue.

T

All capillary beds are continuously perfused with blood.

F

Which of the following would decrease peripheral resistance to blood flow?

anemia

Which organ's blood flow pattern results in low oxygen levels causing vasoconstriction and high oxygen levels causing vasodilation?

lungs

Which of the following is NOT a capillary transport mechanism?

bulk flow

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 signs of hypovolemic shock is a relatively late sign?

rapidly falling blood pressure

Which of the following is likely during vigorous exercise?

Capillaries of the active muscles will be engorged with blood.

Brain blood flow autoregulation ________.

is abolished when abnormally high CO₂ levels persist

Blood flow to the skin ________.

increases when environmental temperature rises

Which of the choices below reflects the balance (or imbalance) between the direction and amount of fluid that flows across the capillary walls?

hydrostatic and osmotic pressure

Which of the following is a type of circulatory shock?

vascular, due to extreme vasodilation as a result of loss of vasomotor tone

The form of circulatory shock known as hypovolemic shock is ________.

shock that results from large-scale loss of blood volume, or after severe vomiting or diarrhea

In the dynamics of blood flow through capillaries, hydrostatic pressure ________.

is the same as capillary blood pressure

Which of the choices below does not involve tissue perfusion?

blood clotting

The velocity of blood flow is ________.

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

Cerebral blood flow is regulated by ________.

intrinsic autoregulatory mechanisms

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

lungs

If blood pressure is almost normal in a person who has lost blood, does that mean the tissues are receiving adequate blood flow?

not necessarily

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

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

T

Every minute, about 1.5 ml of fluid leaks out of the capillaries.

T

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.

T

Examine the lower left figure of Focus Figure 19.17. Assume you have a U-tube with a semipermeable membrane separating the solutions on either side. Predict what will occur to the water level if large nondiffusible solutes are added only to the left arm of the tube.

The water level on the left side of the U-tube will rise.

Assume you have a U-tube with a semipermeable capillary membrane made of simple squamous epithelium separating the solutions on either side. Blood will be on the left side of the tube, and watery extracellular fluid (ECF) will be on the right side of the tube. Predict what will occur to the water levels by hydrostatic pressure, the pressure of watery fluid pushing on a boundary.

A pump pushing down on the left arm of the U-tube containing blood will increase ECF fluid levels on the right side.

Which of the following represents a correct statement about pressures at the arteriolar side of the capillary bed?

The pressures directed into the blood at the arteriolar end are OPc and HPif.

Mr. Orange has hypertension (HTN) and other vessel disorders, and his brachial blood pressure is ~160/100. Assume his HPc is ~44 mm and other pressures are unaffected. What is his NFPa?

NFPa = (44 + 1) - (0 + 26) = +19 mm

Using the same client, Mr. Orange, with the same pressures, what is the client's NFP at the venous end, NFPv?

= (22 + 1) - (26 + 0)= -3 mm

Which vessel leaves the right ventricle of the heart to take oxygen-poor, dark red blood into pulmonary circulation?

pulmonary trunk

Which vessel(s) return(s) oxygenated blood to the left atrium of the heart to complete the pulmonary circuit?

pulmonary vein

Which vessel(s) of the pulmonary circuit transport(s) oxygen-rich blood?

pulmonary veins

Mrs. Gray, a 50-year-old mother of seven children, is complaining of dull, aching pains in her legs. She reports that the pain has been getting progressively worse since the birth of her last child. During her physical examination, numerous varicosities are seen in both legs. What pathologic changes have occurred in these veins?

The veins have become tortuous and dilated because of incompetent valves that allow the blood to pool, stretching the vein walls.

A sustained blood pressure of 140/90 or greater indicates hypertension in the patient.

T

When albumin levels in the blood are below normal, fluid absorption from the tissues into the bloodstream increases.

F

Veins carry only oxygen deficient blood.

F

Which of the following are involved directly in pulmonary circulation?

right ventricle, pulmonary artery, and left atrium

A thrombus (blood clot) in the first branch of the arch of the aorta would affect the flow of blood to the ________.

right side of the head and neck and right upper arm

The pulmonary circulation does not directly serve the metabolic needs of body tissues.

T

Arterial pressure in the pulmonary circulation is much higher than in the systemic circulation because of its proximity to the heart.

F

The cerebral arterial circle (circle of Willis) is an arterial anastomosis.

T