Chapter 19: The Cardiovascular System: Blood Vessels, Mastering A & P

Is the following 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.

Correct

How does inflating a blood pressure cuff affect brachial artery blood flow?

It restricts local circulation.

The pressure of nondiffusible molecules pulling water to them is called colloid _____________________.

Osmotic pressure

What type of vessel is capable of allowing the passage of gases and nutrients though its walls to nourish surrounding tissue?

The thin walls of capillaries allow gases and nutrients to be exchange freely with surrounding cells.

Cardiac Output

The volume of blood pumped out by one ventricle each minute

Assume you have a U-tube with a semipermeable membrane (boundary) 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-tibe will rise. Remember that only nondiffusible solutes will affect the water level, because the solute concentration will increase on the left side, creating osmotic pull. In the blood, nondiffusible solutes are large plasma proteins pulling or drawing fluid into the blood

What is the result and what type of pressure is the following? If water pressure is constant ______________

There is no change in fluid movement Hydrostatic pressure

What is the function of the Tunica Media

Tunica Media- Plays an active role in regulating the diameter of blood vessels/ alters peripheral resisitance / blood pressure

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

capillary; interstitial fluid Yes, the capillary hydrostatic pressure (HPC; caused by blood pressure) is much higher than the interstitial hydrostatic pressure (HPI). The interstitial fluid is forced out of the capillaries.

Where are the sensors for the arterial baroreceptor reflex located?

carotid sinus and aortic arch

Arteries

carry blood away from heart; oxygenated except for pulmonary circulation and umbilical vessels of fetus

Veins

carry deoxygenated blood toward heart except for pulmonary circulation and umbilical vessels;s of fetus

Which of the following would cause vasodilation of arterioles? A)decreased activity of the sympathetic nervous system B)increased activity of the parasympathetic nervous system C)decreased activity of the parasympathetic nervous system D)increased activity of the sympathetic nervous system

decreased activity of the sympathetic nervous system Yes, a decrease in the activity of the sympathetic nervous system would result in decreased activity of vasomotor fibers, resulting in vasodilation.

What is the result and what type of pressure is the following? If the barrier becomes more permeable for solutes

decreased fluid is pulled through boundary Osmotic pressure

What is the result and what type of pressure is the following? If water pressure decreases__________________

decreased fluid is pushed through boundary Hydrostatic pressure

Blood vessels

delivery system of dynamic structure that begin and end at heart

capillaries

direct contact with tissue cells, directly serve cellular needs

capillaries consist of

endothelium and basal lamina

What are some activities or body conditions affect blood pressure by changing Total Peripheral Resistance?

growth, smoking, high altitude living, increased sympathetic activity

What are some physiological changes either increase blood pressure?

increase total peripheral resistance, increase blood viscosity, increase blood volume, increase cardiac output, increase blood vessel length

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 activity and decreased SNS activity

What are some physiological changes either decrease blood pressure?

increased blood vessel diameter

What would NOT be an expected response to a drop in mean arterial pressure?

increased filtration by the kidneys A drop in blood pressure tends to decrease filtration by the kidneys, which precipitates a reduction in urine formation.

What is the result and what type of pressure is the following? If non-diffusible solute concentration increases_________________.

increased fluid is pulled through boundary Osmotic pressure

What is the result and what type of pressure is the following? IF water pressure increases_________________.

increased fluid is pushed through boundary Hydrostatic pressure

Vasoconstrition

is the decrease in the diameter of a Lumen (vessel)

Other than the brain and heart, what organ would hypertension affect the most?

kidney

Which net pressure draws fluid into the capillary?

net osmotic pressure Yes, the proteins exert colloid osmotic pressure, which draws fluid into the capillary.

Blood flow into a capillary bed is regulated by the ________________ sphincter.

precapillary

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

proteins in the blood Yes, the non-diffusible proteins in the plasma exert the colloid osmotic pressure, which pulls fluid into the capillary.

Tunica media is composed of

smooth muscle and elastic fibers

Which of the following would not normally be a direct cause of edema?

tachycardia Edema is an abnormal accumulation of fluid in the interstitial space. It results not from rapid heart rate, but from an increase in outward pressures promoting the movement of fluid out of the capillaries, or from a decrease in pressures drawing fluid back into the venous end of capillary beds.

Total Peripheral resistance

the amount of friction blood encounters during flow through blood vessels

The ______________ or inner-most layer of blood vessels, is made of endothelial tissue.

tunica intima

What are the three layers of blood vessels?

tunica intima, tunica media, tunica externa

What is the bulkiest layer in arteries?

tunica media

Reduction in the diameter of a blood vessel is called _____________, and typically results in an increase in blood pressure.

vasoconstriction

vasdilation

widening of diameter of Lumen (blood vessels)

Tunica media has ________ nerve fibers that innervate is that help control the diameter of the lumen

Sympathetic

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

blood pressure blood pressure is the driving force for filtration.

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

blood vessel diameter

Under normal circumstances,What type of blood vessels are not capable of collapsing?

Arteries

Small arteries that are dilated or constricted to control peripheral resistance, and thus blood pressure, are

Arterioles

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

10% change in vessel diameter

How many walls do all blood vessels except capillaries have?

3

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

34 mm Hg Yes, HPc (35 mm Hg) - HPI (1 mm Hg) = 34 mm Hg, which is the net hydrostatic pressure at the arterial end. The hydrostatic pressure of the blood is much higher at the arterial end of the capillary, thus favoring filtration.

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 levels of fluids 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. Remember that the pushing by water, or hydrostatic pressure, against a boundary can force watery fluid through a semipermeable membrane, from higher to lower pressure.

What are some activities or body conditions affect blood pressure by changing blood volume?

Blood donation and excessive sweating

Which of the following is NOT correct regarding the relationship between pressure, flow, and resistance in the cardiovascular system?

Blood flow (F) is inversely proportional to the pressure gradient (ΔP) in the blood vessels Blood flow (F) is directly proportional to the difference in blood pressure (ΔP) between two points in the circulation-that is, the blood pressure, or hydrostatic pressure, gradient. Consequently, when ΔP increases, blood flow increases, and when ΔP decreases, blood flow declines. On the other hand, blood flow is inversely proportional to the total peripheral resistance (TPR) in the systemic circulation; if TPR increases, blood flow decreases.

Captain Fallowell's drop in blood pressure when standing up is most likely due to:

Decreased cardiac output due to low stroke volume. His heart rate is elevated and his blood vessels are vasoconstricting, yet his blood pressure is low; stroke volume must be the factor that has decreased.

What is the result and what type of pressure is the following? If non-diffusible solute concentration decreases__________________.

Decreased fluid is pulled through boundary Osmotic pressure

Which of these features is found only in arteries? A)valves B)elastic membranes C)vasa vasorum D)lumen

Elastic membranes (internal and external) are found in arteries to help absorb the shock of the heartbeat and return the vessel to its natural size.

All vessels consist of a ________, central blood-containing space, surrounded by a wall

Lumen

When the patient stood up, his heart rate increased. This was most likely caused by which of the following?

The baroreceptor reflex activated by blood pooling in his lower body due to gravity An incompetent aortic valve will interfere with the left ventricle's job of moving blood from the lungs to the body. Blood will accumulate in the lungs, leading to pulmonary congestion.

Blood pressure

The force of the blood against the wall

Blood viscosity

The friction red blood encounter when moving past each other

Tunica initma

The innermost layer that consists of simple squamous epithelium and lines the lume

What is one thing that is found in veins but not arteries?

Valves

During exercise, cardiac output may increase by more than 170% to meet the body's increased O2 demands. 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.

A decrease in blood pressure at the arterial baroreceptors would result in which of the following? A)an increase in heart contractility B)vasodilation of arteriolesa C)decrease in cardiac output D)a decrease in heart rate

an increase in heart contractility Yes, sympathetic nervous system activity would be increased because of the low blood pressure. Sympathetic fibers go to the ventricles of the heart and increase their contractility. An increase in contractility would increase stroke volume which would lead to an increase in cardiac output and blood pressure.

Stimulation of the adrenal medulla would result in which of the following? A)a decrease in cardiac output B)vasodilation of arteriesa C)decrease in blood pressure D)an increase in heart rate and contractility

an increase in heart rate and contractility Yes, epinephrine and norepinephrine are released from the adrenal medulla and act as part of the sympathetic nervous system, increasing heart rate and contractility. Epinephrine and norepinephrine have other effects that would also increase blood pressure.

Tunica Media

middle layer of artery; made up of smooth muscle fibers and thick layer of elastic connective tissue

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

osmotic pressure in capillary (OPc) Osmotic pressure is based on the concentration of dissolved materials that attract water across a membrane. The osmotic pressure in a capillary (OPc) is the force drawing fluid into the blood at the venous end.

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? A)osmotic pressure in the capillary (OPc) drops B)net filtration pressure drops C)interstitial hydrostatic pressure does not play a significant role in capillary pressures D)blood hydrostatic pressure (HPc) drops

osmotic pressure in the capillary (OPc) drops Osmotic pressure remains fairly constant as blood moves from the arteriole to the venous end of the capillary.

The Tunica media is responsible for

vasodilation or vasoconstriction, Which helps maintain good flow blood pressure

Venules unite to form

veins

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

venous Yes, because the hydrostatic pressure of blood (which favors filtration out of the capillary) is lowest in the venous end of the capillary.