112 terms

Blood Vessels

The innermost layer (or tunic) of the blood vessel wall is called the:
tunica intima.
Which layer (or tunic) of the blood vessel wall is composed of smooth muscle and elastin?
Tunica media
Which of the following vessels has the largest lumen and a thin tunica media?
Of the three groups of arteries, which has more smooth muscle, but less elastin, and delivers blood to specific organs?
Muscular arteries
Of the three groups of arteries, which provides the greatest resistance to flow?
To increase blood flow through the true capillaries, which of the following would occur?
Precapillary sphincters would dilate.
Exchange of materials (such as oxygen) between the blood and tissue cells takes place in:
true capillaries.
Blood pressure is lowest in which of the following vessels?
What special adaptation in veins prevents the backflow of blood as it travels toward the heart?
Venous one-way valves
Which type of blood vessel consists of only a thin tunica intima?
Applying norepinephrine to a blood vessel would alter which of the three sources of peripheral resistance?
Vessel diameter
Increasing hematocrit would alter which of the three sources of peripheral resistance?
An increase in fatty tissue in the body would affect which of the three sources of peripheral resistance?
Vessel length
Arteriosclerosis will alter which of the following factors, thus increasing blood pressure?
Vessel diameter
If there is a decrease in blood volume, what would be the effect on blood pressure (BP)?
BP would decrease.
Increased salt intake could lead to an alteration in blood volume, which would do what to blood pressure (BP)?
BP would increase.
Sympathetic stimulation to the heart would alter heart rate, thus __________ cardiac output.
How would stimulation of the vagus nerve alter cardiac output (CO)?
Decrease in CO caused by decreased heart rate
How would increasing stroke volume (SV) alter cardiac output (CO) and blood pressure (BP)?
Increased CO and increased BP
Administering angiotensin II to your patient would __________ the patient's blood pressure.
The maximum pressure reached in the arteries is called:
systolic pressure (SP).
The dicrotic notch represents the brief interruption of smooth blood flow caused by the backflow of blood that closes which valve?
Aortic semilunar
Which of the following pressures is usually 80 mm Hg?
Diastolic pressure
The difference between systolic pressure and diastolic pressure is called:
pulse pressure.
The calculated "average" pressure in the arteries is called the:
mean arterial pressure.
When the pressure in the blood pressure cuff is greater than in the artery, what sounds, if any, would you hear?
No sounds
The first sound you hear through the stethoscope as pressure in the cuff is released is recorded as:
systolic pressure.
What is the correct formula for calculating mean arterial pressure (MAP)?
DP + PP/3
Calculate pulse pressure, given SP = 110 mm Hg and DP = 70 mm Hg.
40 mm Hg
Calculate MAP, given SP = 130 mm Hg and DP = 70 mm Hg.
90 mm Hg
The long-term mechanism for regulation of blood pressure involves regulating which of the following?
Blood volume
The aortic arch and the carotid sinus contain nerve endings that monitor blood pressure by the degree of stretch on the vessel wall. These sensors are called:
arterial baroreceptors.
A change in blood pressure that increases the impulses to the cardiovascular center results in increased impulses from which branch of the autonomic nervous system? What would be the effect on blood pressure (BP)?
Parasympathetic; decreased BP
A change in blood pressure that decreases the impulses to the cardiovascular center results in increased impulses from which branch of the autonomic nervous system? What would be the effect on blood pressure (BP)?
Sympathetic; increased BP
Increased activity of the vagus nerve would cause the heart rate to __________.
Increased sympathetic nerve activity at the heart would cause:
an increase in both heart rate and contractility.
The sympathetic nervous system also stimulates the release of epinephrine and norepinephrine from what gland?
Adrenal gland
What cells in the kidney monitor blood pressure, releasing renin when blood pressure is low?
Juxtaglomerular cells
How does angiotensin II raise blood pressure?
Directly by increasing vasoconstriction and indirectly by stimulating aldosterone release
An increase in plasma osmolarity stimulates release of what hormone from the posterior pituitary?
Antidiuretic hormone (ADH)
What regulates the flow of blood into true capillaries?
Precapillary sphincters
Which of the following combinations would increase blood flow in capillaries the most?
Low O2 and high CO2
Which of the following combinations would increase blood flow in capillaries the most?
Decreased nutrients and fever
Oxygen and carbon dioxide move through the blood vessel wall primarily by which of the following mechanisms?
Water soluble solutes, such as amino acids, move through the blood vessel walls by which of the following mechanisms?
Clefts or fenestrations
Bulk fluid flow causes ____________ at the arterial end and ______________ at the venous end of the capillary.
filtration; reabsorption
Hydrostatic pressure in the capillary (that is, blood pressure) forces fluid _____ the capillary.
out of
Calculate the net hydrostatic pressure at the arterial end of the capillary if the hydrostatic pressure of the blood is 35 mm Hg and the hydrostatic pressure of the interstitial fluid is 1 mm Hg.
34 mm Hg
The osmotic pressure of blood (that is, the plasma proteins) in the capillary forces fluid _____ the capillary.
If net hydrostatic pressure is higher than net osmotic pressure, will fluid enter or leave the capillary?
During pulmonary circulation blood leaves the:
right ventricle and moves to the lungs.
During systemic circulation blood leaves the:
left ventricle and goes directly to the aorta.
The endothelium is composed of:
simple squamous epithelium.
The inferior vena cava brings blood from the lower regions of the body and empties into the:
right atrium.
Which is the correct sequence of layers in the vessel wall from outside to inside?
Tunica externa, tunica media, tunica interna
The major long-term mechanism of blood pressure control is provided by the:
The kidneys act both directly and indirectly to regulate arterial pressure and provide the major long-term mechanism of blood pressure control.
Exchange of gases and nutrients occurs by diffusion between the:
capillaries and tissue cells.
Any condition in which blood vessels are inadequately filled and blood cannot circulate normally is called:
circulatory shock.
Reduction in lumen diameter of a blood vessel as the smooth muscle contracts is known as:
The only vessels that provide direct access to nearly every cell in the body are the:
Which of the following regulates blood flow at the entrance to each true capillary?
Precapillary sphincter
Loss of vasomotor tone resulting in a huge drop in peripheral resistance is known as:
vascular shock.
Which of the following arteries branches to form the common hepatic artery, left gastric artery, and splenic artery?
Celiac trunk
Which of the following veins is the longest in the body?
Great saphenous vein
The great saphenous vein is the longest in the body, running from the sole of the foot up to the inguinal region (without changing names).
Which of the layers of an artery wall is regulated by the sympathetic nervous system and many hormones?
Middle layer
Which of the following types of blood vessels have the thickest tunica media of all vessels?
Distributing arteries
What can compete with plasminogen but cannot dissolve clots and may contribute to the formation of atherosclerotic plaques?
Lipoprotein (a)
The minute-to-minute blood flow through the capillary beds is determined by the:
diameter of arterioles.
The presence of ___________ stabilizes the wall of capillaries.
All but which of the following blood vessels contain intercellular clefts?
The flow of blood from an arteriole to a venule is called the:
A metarteriole is a vessel that:
intermediate between the arteriole and the capillary bed.
Which of the following conditions would NOT increase the chances of developing varicose veins?
Running in place
Up to 65% of the body's blood supply is found in:
All of the following are examples of sinuses, except:
capillary sinuses.
Most neural controls of blood pressure involve input from baroreceptors, which are sensitive to:
to changes in blood pressure.
An elastic lamina on both sides of the tunica media is a characteristic of:
muscular arteries.
Which of the following blood vessels is the most susceptible to atherosclerosis?
The aorta
Which of the following is the major force generating blood flow?
Pumping action of the heart
Blood enters the myocardium of the heart by coronary vessels that originate from the:
T/F - The superior vena cava, inferior vena cava, and the coronary sinus empty into the left atrium.

The superior vena cava, inferior vena cava, and the coronary sinus bring blood from all over the body and empty into the right atrium.
T/F - Blood pressure in capillaries is lower than in arterioles.

By the time blood reaches the capillaries, blood pressure has dropped.
T/F - Hypotension is commonly called high blood pressure.

High blood pressure is called hypertension.
T/F - The heart produces a hormone called atrial natriuretic peptide that causes blood volume and blood pressure to decline.

ANP antagonizes aldosterone and prods the kidneys to excrete more sodium and water from the body.
T/F - Orthostatic hypotension causes blood pressure to rise by increasing effects of ADH.

Orthostatic hypotension is temporary low blood pressure when rising from a reclining or sitting position due to pooling of blood in the lower limbs, which reduces blood flow to the brain.
T/F - Atherosclerosis begins in youth but seldom causes noticeable problems until middle to old age.

From middle to old age, atherosclerosis may precipitate a myocardial infarct or stroke.
T/F - The most important factor in regulation of blood pressure is peripheral resistance.

Because peripheral resistance is the most quickly changed variable in blood pressure, it is the most important for regulation.
T/F - The vertebral artery supplies the brain with blood.

Together with the internal carotid artery, the vertebral artery contributes to the Circle of Willis, an arterial anastomosis for the brain.
The vessel layer that has a direct role in vasoconstriction is the:
tunica media.
Blood flows directly from _____ into capillary beds.
The vessels that exhibit the lowest level of permeability are the:
continuous capillaries.
When would the capillary beds surrounding the gastrointestinal organs be open?
During a meal
T/F - Baroreceptors are effective in long-term regulation of blood pressure.
Short-term blood pressure regulation involves both neural and hormonal controls. Neural control is regulated by higher order brain centers, chemoreceptors, and baroreceptors. Long-term control of blood pressure is achieved through direct and indirect renal (kidney) control mechanisms.
Which of the following is true when comparing arteries and veins?
Arteries carry blood away from the heart; veins carry blood to the heart.
Blood flow would be increased by:
increasing cardiac output.
Systolic pressure
Peak of aortic pressure
Systolic pressure is the peak pressure achieved as the heart ejects blood into the aorta, averaging about 120 mm Hg in healthy adults.
Diastolic pressure
Lowest level of aortic pressure
Diastolic pressure is the lowest aortic pressure, approximately 70-80 mm Hg in healthy adults.
Pulse pressure
The difference between systolic and diastolic pressure
Mean arterial pressure
Pressure that propels blood to the tissues
Which of the following acts on the kidneys to raise blood pressure?
Antidiuretic hormone
Hypertension is defined physiologically as a condition of sustained arterial pressure of ______ or higher.
T/F - If the net filtration pressure (NFP) is positive, then fluid is reabsorbed into the blood.
A positive net filtration pressure (NFP) would force fluid out of the blood. A negative NFP would result in reabsorption.
Which of the following would experience increased blood flow during exercise?
Fluids would be likely to leave or filter out of the capillary if:
net hydrostatic pressure (HP) is greater than net osmotic pressure (OP).

A positive net filtration pressure (NFP) would result in filtration. A negative NFP would result in reabsorption. NFP is affected by net hydrostatic pressure (HP) and net osmotic pressure (OP). If net HP is greater than net OP, filtration results. If net HP is less than net OP, reabsorption occurs. This is easier to remember if you think of HP as a filtration force and OP as a reabsorption force.
Cardiogenic shock is most likely to result from:
multiple heart attacks.
Vascular shock occurs when blood volume is normal but vasomotor tone is suddenly lost, causing extreme vasodilation. The massive vasodilation event leads to a drastic and dangerous drop in blood pressure. Vascular shock can be triggered by anaphylaxis, septic shock, and by certain bacterial toxins. Hypovolemic shock is a result of large-scale blood loss; it is the most common form of circulatory shock. Cardiogenic shock is a result of heart failure or damage; it can result from multiple myocardial infarcts (heart attacks).
Blood flows from the lungs to the _________ via the ___________.
left atrium; pulmonary veins
Blood from the brain is returned to the heart via the:
superior vena cava.
The hepatic portal system collects blood from the ______ and then routes it to the ______.
GI tract; liver
Nitric oxide
Metabolic control of blood flow
Stretch of vascular smooth muscle
Myogenic control of blood flow
Sympathetic impulses
Nervous system control of blood flow
Angiotensin II
Hormonal control of blood flow