chap 19 Blood vessels
The aorta is an example of a(n) __________.
elastic artery
Which type of vessel contains elastin in all three tunics to allow the vessel to expand and recoil as the heart ejects blood? (pic)
elastic artery
What type of tissue is found in the walls of the arteries but not in the walls of capillaries and venules?
elastic tissue
Which of the following is not one of the three main factors influencing blood pressure?
emotional state
Which of the following intrinsic mechanisms (autoregulation) for controlling arteriolar smooth muscle diameter promotes vasoconstriction? (Pic)
endothelins
Arteriolar blood pressure increases in response to all but which of the following?
falling blood volume
Substances absorbed in the intestines would be routed to the liver via the __________.
hepatic portal vein
Which vein carries nutrient rich blood from the digestive system to the liver?
hepatic portal vein
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
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
Peripheral resistance ________.
increases as blood viscosity increases
Blood flow to the skin ________.
increases when environmental temperature rises
Blood from the lower limbs is returned to the heart via the __________.
inferior vena cava
Cerebral blood flow is regulated by ________.
intrinsic autoregulatory mechanisms
Brain blood flow autoregulation ________.
is abolished when abnormally high CO2 levels persist
In the dynamics of blood flow through capillaries, hydrostatic pressure ________.
is the same as capillary blood pressure
Which of the following would experience a decreased blood flow during exercise?
kidneys
What do the ductus arteriosus and the foramen ovale become at birth?
ligamentum arteriosum; fossa ovalis
Which of the following is a metabolic factor that influences blood flow? (pic)
low oxygen levels
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
Where in the body would you find low oxygen levels causing vasoconstriction and high levels causing vasodilation?
lungs
Which organ's blood flow pattern results in low oxygen levels causing vasoconstriction and high oxygen levels causing vasodilation?
lungs
Assume a person is experiencing a hemorrhage and the HPc 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. (pic)
-2 mm Hg
What is the value for the net filtration pressure (NFP) at the arteriolar end of the capillary? (pic)
10 mm Hg
The arteries that are also called distributing arteries are the ________.
muscular arteries
What type of vessel has relatively more smooth muscle and less elastic tissue? (pic)
muscular artery
Which net pressure draws fluid into the capillary?
net osmotic pressure
Which of the following chemicals does not help regulate blood pressure?
nitric acid
Which of the following is a stimulus in local autoregulation of blood flow?
nitric oxide
Which of the following blood pressure readings would be indicative of hypertension?
170/96 in a 50-year-old man
Which of the following promotes vasodilation? (Pic)
nitric oxide
Which of the following would reflect the typical net hydrostatic pressure (HP) at the arterial end of the capillary?
34 mm Hg
Calculate mean arterial pressure (MAP) if systolic blood pressure is 120 mm Hg and diastolic blood pressure is 70 mm Hg. (pic)
87 mm Hg
Normal average blood pressure for a newborn baby is ________.
90/55
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
What pressure is responsible for reabsorption and for pulling fluids into the venous end of capillaries? (pic)
osmotic pressure in capillary (OPc)
Which artery branches into the common hepatic artery, splenic artery, and left gastric artery? Select from letters A-D. (pic)
A
Which artery branches off the subclavian arteries? Select from letters A-D. (pic)
A
Which vein becomes the external iliac vein as it enters the pelvis? Select from letters A-D. (pic)
A
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.
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.
Which statement best describes arteries?
All carry blood away from the heart.
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? (pic)
Angiotensin II promotes vasodilation that decreases peripheral resistance.
Aldosterone will ________.
promote an increase in blood pressure
Which of the following would NOT move by diffusion across a capillary endothelium to or from the surrounding interstitial fluid and tissues?
proteins
The colloid osmotic pressure in the capillary is caused by __________.
proteins in the blood
Which vein is the longest in the body and empties into the femoral vein? Select from letters A-D. (pic)
B
Why is it important that blood pressure drop to lower levels as it reaches the capillary beds?
Because capillaries are fragile and extremely permeable.
Select the correct statement about blood flow.
Blood flow through the entire vascular system is equivalent to cardiac output.
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.
Which arteries carry deoxygenated blood?
pulmonary arteries
Which vessel leaves the right ventricle of the heart to take oxygen-poor, dark red blood into pulmonary circulation? (pic)
pulmonary trunk
Which vessel(s) return(s) oxygenated blood to the left atrium of the heart to complete the pulmonary circuit? (pic)
pulmonary vein
Which vessel(s) of the pulmonary circuit transport(s) oxygen-rich blood? (pic)
pulmonary veins
Which of the following signs of hypovolemic shock is a relatively late sign?
rapidly falling blood pressure
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.
What vein is formed from the union of the anterior tibial vein and posterior tibial vein? Select from letters A-D. (pic)
C
Which artery serves nearly all of the small intestine via the intestinal arteries and most of the large intestine via the ileocolic, middle colic, and right colic arteries? Select from letters A-D. (pic)
C
Which vessel sends branches to the thyroid, larynx, tongue, skin, and muscles of the anterior face and posterior scalp? Select from letters A-D. (pic)
C
Which of the following is likely during vigorous exercise?
Capillaries of the active muscles will be engorged with blood.
Which artery serves the distal part of the large intestine via its left colic, sigmoidal, and superior rectal branches? Select from letters A-D. (pic)
D
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.
Select the correct statement about factors that influence blood pressure.
Excess red cell production would cause a blood pressure increase.
All capillary beds are continuously perfused with blood.
False
Arterial pressure in the pulmonary circulation is much higher than in the systemic circulation because of its proximity to the heart.
False
Osmotic pressure is created by the presence in a fluid of small diffusible molecules that easily move through the capillary membrane.
False
The outermost layer of a blood vessel is the tunica intima.
False
The pancreas is an example of an organ with arteries that do not anastomose.
False
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.
False
Veins carry only oxygen deficient blood.
False
When albumin levels in the blood are below normal, fluid absorption from the tissues into the bloodstream increases.
False
Which of the following is involved in long-term blood pressure regulation?
renal mechanisms
Which of the following is a long-term mechanism for maintaining blood pressure?
renal regulation
Which of the following processes provides a long-term response to changes in blood pressure?
renal regulation
Which of the following is not true regarding fenestrated capillaries?
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?
Increased blood pressure. This is due to increased sodium in the blood, increasing the total extracellular fluid volume.
Which of the following statements regarding the hepatic portal system is false?
It branches off of the inferior vena cava.
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.
__________ is the pressure that propels blood to the tissues.
Mean arterial pressure
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.
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.
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 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
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.
A precapillary sphincter is a cuff of smooth muscle that regulates the flow of blood into the capillaries.
True
A sustained blood pressure of 140/90 or greater indicates hypertension in the patient.
True
An increase in blood viscosity will cause an increase in peripheral resistance.
True
An obstruction in the superior vena cava would decrease the flow of blood from the head and neck to the heart.
True
Arteries supplying the same territory are often merged with one another, forming arterial anastomoses.
True
Every minute, about 1.5 ml of fluid leaks out of the capillaries.
True
Hypotension is generally considered systolic blood pressure that is below 100 mm Hg.
True
The adjustment of blood flow to each tissue in proportion to its requirements at any point in time is termed autoregulation.
True
The azygos vein originates in the abdomen.
True
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.
True
The cerebral arterial circle (circle of Willis) is an arterial anastomosis.
True
The pulmonary circulation does not directly serve the metabolic needs of body tissues.
True
Vasodilation will result in increased blood flow to a given tissue.
True
Which of the following are involved directly in pulmonary circulation?
right ventricle, pulmonary artery, and left atrium
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
Which of the following is true about veins?
Veins are called capacitance vessels or blood reservoirs.
Which of the following is true about veins?
Veins have valves; arteries do not.
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 term ductus venosus refers to ________.
a special fetal vessel that allows umbilical blood to bypass the liver
Which hormone of the indirect renal mechanism promotes sodium reabsorption by the kidneys to increase mean arterial pressure? (pic)
aldosterone
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
A decrease in blood pressure at the arterial baroreceptors would result in which of the following?
an increase in heart contractility
Stimulation of the adrenal medulla would result in which of the following?
an increase in heart rate and contractility
Which of the following would decrease peripheral resistance to blood flow?
anemia
Which vessels carry blood away from the heart?
arteries
The arteries that directly feed into the capillary beds are called ________.
arterioles
What blood vessel experiences the steepest drop in blood pressure? (pic)
arterioles
Secondary hypertension can be caused by ________.
arteriosclerosis
Which of the following will lower blood pressure?
atrial natriuretic peptide (ANP)
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 choices below does not involve tissue perfusion?
blood clotting
In the capillaries, hydrostatic pressure (HP) is exerted by __________.
blood pressure
Which of the following is the most significant source of blood flow resistance?
blood vessel diameter
From what artery does the right common carotid artery arise? (pic)
brachiocephalic trunk
Which of the following is NOT a capillary transport mechanism?
bulk flow
Gas and nutrient exchanges between the blood and tissues take place at the __________.
capillaries
Permitting the exchange of nutrients and gases between the blood and tissue cells is the primary function of ________.
capillaries
What vessels sustain a drop in pressure from approximately 35 mm Hg to around 17 mm Hg? (pic)
capillaries
The net hydrostatic pressure (HP) is the hydrostatic pressure in the __________ minus hydrostatic pressure in the __________.
capillary; interstitial fluid
Where are the sensors for the arterial baroreceptor reflex located?
carotid sinus and aortic arch
The baroreceptors in the carotid sinus and aortic arch are sensitive to which of the following?
changes in arterial pressure
Which capillaries are the most common in the body?
continuous capillaries
The most common type of blood capillary is the ________.
continuous capillary
Which of the following would be interrupted in the indirect renal mechanism if angiotensin converting enzyme (ACE) is blocked from performing its job? (pic)
conversion of angiotensin I into angiotensin II
Which of the following would cause vasodilation of arterioles?
decreased activity of the sympathetic nervous system
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 influence of blood vessel diameter on peripheral resistance is ________.
significant because resistance is inversely proportional to the fourth power of the vessel radius
Leaky capillaries found in the bone marrow are called __________.
sinusoidal capillaries
Modified capillaries that are lined with phagocytes are called ________.
sinusoids
The velocity of blood flow is ________.
slowest in the capillaries because the total cross-sectional area is the greatest
The pulse pressure is ________.
systolic pressure minus diastolic pressure
Mechanisms that do not help regulate blood pressure include ________.
the dural sinus reflex
Which of the following do not influence arterial pulse rate?
the vessel selected to palpate
The inferior vena cava carries blood __________ the __________ of the heart.
to; right atrium
Which of the following is NOT an important source of resistance to blood flow?
total blood volume
What is the outermost layer of the blood vessel wall for an artery or vein? (pic)
tunica externa
Histologically, the ________ is squamous epithelium supported by a sparse connective tissue layer.
tunica intima
Which layer of the typical blood vessel is constructed from simple squamous epithelium? (pic)
tunica intima
Which layer of the typical vessel can be regulated via vasoconstriction or vasodilation? (pic)
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 ________.
urinary output
Which of the following would be a result of anaphylaxis (a systemic allergic reaction)?
vascular shock
Which of the following is a type of circulatory shock?
vascular, due to extreme vasodilation as a result of loss of vasomotor tone
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)? (pic)
vein
Reabsorption of fluid into the capillary takes place at the arterial end or venous end of the capillary?
venous