Phys 17 Flashcards

During exercise, coronary and skeletal-muscle perfusion increase primarily because most tissues regulate local blood flow in proportion to:

A. Metabolic needs
B. Venous pressure
C. Lymphatic drainage
D. Arterial viscosity

In a febrile patient, increased blood flow to which tissue most directly increases heat loss?

A. Liver
B. Skin
C. Spleen
D. Bone

Which statement best describes blood flow to inactive skeletal muscle at rest?

A. Very high, due to mass
B. Moderate, due to tone
C. Very low, despite size
D. Equal to skin flow

Although skeletal muscle makes up roughly 30–40% of body mass, blood flow to inactive muscle is usually:

A. Markedly elevated
B. Very low
C. Highly pulsatile only
D. Fixed by hormones

Under usual conditions, tissue blood flow is regulated near the:

A. Maximal reserve level
B. Random average level
C. Minimal adequate level
D. Highest oxygen level

Maintaining tissue perfusion at the minimal adequate level chiefly helps reduce workload on the:

A. Heart
B. Lung
C. Kidney
D. Liver

Local blood-flow regulation is classically divided into:

A. Neural and endocrine
B. Acute and long term
C. Arterial and venous
D. Pressure and volume

Acute local blood-flow control is produced mainly by:

A. New vessel growth
B. Protein synthesis
C. Rapid vasomotor changes
D. Hormonal receptor upregulation

Acute control acts predominantly at which vascular sites?

A. Veins and venules
B. Aorta and vena cava
C. Lymphatics and capillaries
D. Arterioles and metarterioles

Long-term local blood-flow control refers to changes occurring over:

A. Seconds to minutes
B. Minutes to hours
C. Days to months
D. Single cardiac cycles

Which condition decreases oxygen availability to tissues?

A. Hyperventilation alone
B. Carbon monoxide poisoning
C. Polycythemia vera
D. Hyperbaric oxygen

Which additional condition can reduce tissue oxygen availability?

A. Pneumonia
B. Hypothyroidism
C. Nephrotic syndrome
D. Mitral stenosis

A climber at very high altitude develops local compensatory vasodilation. The initiating problem is reduced tissue availability of:

A. Sodium
B. Oxygen
C. Calcium
D. Albumin

Which substance is a local vasodilator?

A. Histamine
B. Endothelin
C. Thromboxane
D. Serotonin only

Which combination contains only vasodilator substances listed in your material?

A. Potassium, hydrogen, adenosine
B. Calcium, sodium, angiotensin
C. Endothelin, norepinephrine, ADH
D. Thromboxane, serotonin, renin

Local vasodilator substances are often released in response to:

A. Oxygen deficiency
B. Glucose excess
C. Increased oncotic pressure
D. High arterial pressure

According to the oxygen-demand theory, absence of oxygen causes vessels to:

A. Spasm intermittently
B. Dilate
C. Fibrose
D. Thrombose

At the origin of the capillary lies the:

A. Metarteriole shunt
B. Postcapillary venule
C. Precapillary sphincter
D. Arteriovenous anastomosis

The cyclical opening and closing of precapillary sphincters is called:

A. Vasospasm
B. Vasomotion
C. Vasculogenesis
D. Autoperfusion

Increasing local oxygen concentration tends to increase the ______ of precapillary and metarteriole sphincter contraction.

A. Duration
B. Strength
C. Frequency
D. Velocity

Lack of glucose in perfusing blood most directly causes local tissue:

A. Vasodilation
B. Venoconstriction
C. Lymphatic collapse
D. Capillary rupture

A malnourished patient with thiamine deficiency develops warm extremities and low peripheral resistance. This vasodilation is most characteristic of:

A. Scurvy
B. Pellagra
C. Beriberi
D. Kwashiorkor

In beriberi, peripheral vascular blood flow is typically:

A. Unchanged
B. Halved
C. Tripled to quadrupled
D. Increased two- to threefold

Reactive hyperemia occurs after:

A. Increased metabolism
B. Temporary arterial occlusion
C. Venous thrombosis
D. Chronic hypertension

A forearm cuff is inflated for several minutes, then released. The transient overshoot in flow that follows is:

A. Active hyperemia
B. Venous pooling
C. Reactive hyperemia
D. Myogenic escape

Active hyperemia most directly follows increased tissue:

A. Metabolic activity
B. Fibrotic remodeling
C. Venous return
D. Colloid pressure

Once previously increased local blood flow falls back toward normal, this return is termed:

A. Vasomotion
B. Autoregulation
C. Capillary recruitment
D. Sympathetic escape

Which pair lists the two main acute autoregulatory theories?

A. Metabolic and myogenic
B. Neural and endocrine
C. Osmotic and oncotic
D. Cardiac and venous

In the myogenic theory of acute autoregulation, stretch of small blood vessels causes:

A. Endothelial apoptosis
B. Immediate dilation
C. Contraction
D. Valve closure

Which vignette best illustrates active rather than reactive hyperemia?

A. Flow rises after cuff release
B. Flow rises after exercise
C. Flow rises after hemorrhage
D. Flow rises after standing

A patient’s arterioles constrict when arterial pressure suddenly rises, helping protect the vessel wall. This myogenic mechanism is most important for preventing excessive:

A. oxygen extraction
B. metabolic demand
C. stretching
D. vascular sprouting

Renal blood-flow autoregulation is classically controlled by:

A. tubuloglomerular feedback
B. baroreceptor discharge
C. venous capacitance
D. lymphatic drainage

Increased NaCl delivery to the macula densa causes afferent arteriolar constriction primarily to normalize:

A. renal vein pressure
B. filtration fraction
C. medullary osmolarity
D. GFR

The level of excitability of the brain depends importantly on control of:

A. sodium and chloride
B. carbon dioxide and hydrogen
C. calcium and magnesium
D. glucose and phosphate

Nitric oxide released in the vasculature is produced mainly by:

A. endothelial cells
B. platelets
C. smooth muscle cells
D. neutrophils

Endothelial nitric oxide is synthesized from which substrates by eNOS?

A. citrulline and carbon dioxide
B. ornithine and nitrogen
C. arginine and glucose
D. arginine and oxygen

Nitric oxide has a blood half-life of only a few seconds, so its effects are mainly:

A. endocrine
B. systemic
C. genomic
D. local

Increased blood flow stimulates endothelial nitric oxide release mainly through:

A. shear stress
B. low oncotic pressure
C. venous collapse
D. platelet adhesion

Which vasoconstrictor can paradoxically stimulate endothelial nitric oxide release to limit excessive constriction?

A. norepinephrine
B. endothelin
C. angiotensin II
D. thromboxane A2

The most important vasoconstrictor released by endothelial cells is:

A. prostacyclin
B. endothelin
C. bradykinin
D. histamine

The usual stimulus for endothelin release is:

A. endothelium injury
B. low glucose delivery
C. high venous pressure
D. lymphatic obstruction

Endothelin-receptor blockers are used clinically to treat:

A. essential hypertension
B. portal hypertension
C. malignant edema
D. pulmonary hypertension

A key mechanism for long-term local blood-flow regulation is changing tissue:

A. viscosity
B. vascularity
C. oxygen affinity
D. contractility

A tissue with chronically increased metabolism develops more microvessels over weeks. This process is called:

A. vasomotion
B. autoregulation
C. angiogenesis
D. myogenic escape

A neonatal retinal vascular overgrowth syndrome associated with blindness is called:

A. cataracta brunescens
B. papilledema
C. diabetic retinopathy
D. retrolental fibroplasia

Which set contains only factors that increase growth of new blood vessels?

A. VEGF, PDGF, angiogenin, FGF
B. endothelin, renin, ADH, serotonin
C. histamine, bradykinin, NO, cortisol
D. thromboxane, aldosterone, ANP, dopamine

Angiogenesis begins with new vessels ______ from existing small vessels.

A. looping
B. fusing
C. sprouting
D. collapsing

Steroid hormones and angiostatin act ______ angiogenesis.

A. opposite to
B. synergistically with
C. independently of
D. downstream from

Small vessels chronically exposed to higher pressure may reorganize around a smaller lumen diameter. This is called:

A. outward hypertrophic remodeling
B. inward eutrophic remodeling
C. concentric hyperplasia
D. fixed vasomotion

In chronic pressure loading, large arteries that fail to constrict to rising pressure respond with:

A. Vasomotion
B. Inward remodeling
C. Hypertrophic remodeling
D. Capillary sprouting

The hallmark of chronic hypertension is:

A. Stiffer blood vessels
B. Dilated venules
C. Lower shear stress
D. Thin arterial walls

A vessel exposed to chronically high flow and shear stress enlarges its lumen while wall thickness stays the same. This is:

A. Inward eutrophic remodeling
B. Outward hypertrophy
C. Hypertrophic remodeling
D. Outward remodeling

On the venous side of an arteriovenous fistula, increased pressure and flow most directly cause:

A. Inward remodeling
B. Outward hypertrophic remodeling
C. Pure vasospasm
D. Capillary rarefaction

During increased cardiac activity, epinephrine may produce vasodilation in the:

A. Coronary arteries
B. Renal arteries
C. Cutaneous arterioles
D. Splanchnic veins

Which listed substance is a vasodilator?

A. Vasopressin
B. Norepinephrine
C. Bradykinin
D. Angiotensin II

Which listed substance is a vasoconstrictor?

A. Histamine
B. Vasopressin
C. Bradykinin
D. Kallidin

The kinins are small polypeptides cleaved by proteolytic enzymes from:

A. Albumins
B. Gamma globulins
C. Beta globulins
D. Alpha2-globulins

Bradykinin is inactivated by which enzyme?

A. Renin
B. Kallikrein
C. Elastase
D. Converting enzyme

Activated kallikrein is destroyed by a:

A. Histamine esterase
B. Kallikrein inhibitor
C. Cyclooxygenase
D. Bradykininase

Bradykinin causes powerful arteriolar dilation and increased:

A. Capillary permeability
B. Venous compliance
C. Lymphatic tone
D. RBC deformability

In damaged tissues, histamine is derived mainly from:

A. Basophils
B. Platelets
C. Mast cells
D. Neutrophils

In the blood, histamine is derived from:

A. Eosinophils
B. Monocytes
C. Basophils
D. Platelets

Histamine-induced arteriolar dilation and increased capillary porosity can cause marked:

A. Edema
B. Cyanosis
C. Thrombosis
D. Vasospasm

Which ion most strongly favors vasoconstriction?

A. Potassium
B. Hydrogen
C. Magnesium
D. Calcium

Which ion most strongly favors vasodilation?

A. Calcium
B. Potassium
C. Sodium
D. Phosphate

Which ion is also associated with vasodilation?

A. Magnesium
B. Calcium
C. Chloride
D. Iron

Increased tissue carbon dioxide causes vasodilation especially in the:

A. Kidney
B. Liver
C. Skin
D. Brain

Which sequence ranks blood flow highest to lowest?

A. Kidney > liver > muscles > thyroid
B. Liver > thyroid > kidney > muscles
C. Kidney > liver > thyroid > muscles
D. Liver > kidney > thyroid/adrenal > muscles

In outward remodeling driven by high flow and shear stress, wall thickness is usually:

A. Increased
B. Unchanged
C. Decreased
D. Fibrotic

Which peptide is named as the immediate precursor converted to bradykinin?

A. Histamine
B. Angiotensin
C. Kallikrein
D. Kallidin

Which pair are both listed vasodilators?

A. Bradykinin and histamine
B. Epinephrine and ADH
C. Norepinephrine and ADH
D. Angiotensin and epinephrine

Which enzyme besides converting enzyme inactivates bradykinin?

A. Renin
B. Trypsin
C. Carboxypeptidase
D. Cyclase

A coronary artery transiently underperfuses working myocardium. Which local metabolite is especially important for restoring coronary blood flow?

A. Adenosine
B. Endothelin
C. Angiotensin II
D. Vasopressin

Increased cardiac activity most directly causes which change inside heart muscle cells?

A. Increased intracellular oxygen
B. Decreased ATP breakdown
C. Decreased adenosine release
D. Decreased oxygen concentration

In the heart, increased metabolic activity causes which paired change?

A. Increased oxygen, less adenosine
B. More ATP degradation, more adenosine
C. Less ATP degradation, less flow
D. More oxygen, less vasodilation

The number of open precapillary sphincters is most proportional to tissue:

A. Nutritional requirement
B. Venous pressure
C. Sympathetic tone
D. Capillary hydrostatic pressure

The duration of precapillary sphincter opening is most proportional to tissue need for:

A. Sodium
B. Amino acids
C. Oxygen
D. Chloride

The strength of vascular smooth-muscle contraction is most proportional to local concentration of:

A. Glucose
B. Potassium
C. Adenosine
D. Oxygen

Rising local oxygen concentration most directly causes precapillary sphincters to:

A. Open wider
B. Constrict more strongly
C. Lose smooth muscle tone
D. Become pressure-insensitive

Which vitamin-deficiency pattern is most associated with beriberi-related vasodilation in your notes?

A. A, D, E
B. Thiamine, niacin, riboflavin
C. B12, folate, biotin
D. C, K, niacin

Autoregulation is especially precise in which two organs?

A. Liver and skin
B. Kidney and spleen
C. Lungs and intestine
D. Brain and heart

Which statement best describes the myogenic theory of acute autoregulation?

A. Excess flow creates more vasodilators
B. Sudden vessel stretch triggers contraction
C. High pressure relaxes arterioles directly
D. Low pressure causes immediate constriction

Which juxtaglomerular apparatus structure detects increased tubular flow at the distal convoluted tubule and helps restore filtration toward normal?

A. Extraglomerular mesangium
B. Macula densa
C. Proximal convoluted tubule
D. Collecting duct principal cells

When the macula densa senses excessive distal tubular flow from increased renal blood flow, the immediate corrective response is usually:

A. Afferent arteriolar constriction
B. Efferent arteriolar dilation
C. Renin release from JG cells
D. Mesangial relaxation only

A patient with hypercapnia develops a compensatory cerebrovascular response. Increased brain CO2 and H+ most directly cause:

A. Cerebral vasoconstriction
B. Reduced cerebral flow
C. Cerebral vasodilation
D. Blood-brain barrier closure

The major purpose of cerebral vasodilation in response to elevated brain CO2 or H+ is to:

A. Increase CSF formation
B. Wash out excess CO2 and H+
C. Lower neuronal metabolism
D. Increase venous resistance

Which statement best describes control of cutaneous and subcutaneous blood flow?

A. It is mainly fixed locally
B. It is regulated by sympathetic nerves
C. It depends only on venous tone
D. It is independent of CNS input

During environmental heat exposure, rising body temperature normally causes skin blood flow to:

A. Decrease sharply
B. Remain unchanged
C. Increase
D. Become pressure-passive

During cold exposure, the usual thermoregulatory response in skin is:

A. Vasodilation to lose heat
B. Decreased skin blood flow
C. Increased capillary permeability
D. Loss of sympathetic tone

Even during marked cutaneous vasoconstriction, some skin flow is still maintained primarily to meet:

A. Lymphatic demand
B. Hair-follicle cycling
C. Sweat-gland reserve
D. Skin metabolic needs

Chronic hypertension and atherosclerosis damage endothelium. Reduced nitric oxide release in that setting most strongly promotes:

A. Excessive vasoconstriction
B. Excessive vasodilation
C. Capillary rupture
D. Venous pooling

PDE-5 normally promotes vasoconstriction mainly by:

A. Blocking guanylate cyclase
B. Degrading cAMP
C. Degrading cGMP
D. Inhibiting eNOS directly

A PDE-5 inhibitor prolongs nitric oxide–mediated vasodilation primarily by:

A. Increasing endothelin release
B. Preventing cGMP breakdown
C. Blocking arginine uptake
D. Lowering shear stress

One physiologic role of endothelin is to:

A. Promote angiogenesis
B. Increase cGMP
C. Dilate cerebral arterioles
D. Limit arterial bleeding

If tissue metabolism remains elevated for a prolonged period, tissue vascularity generally:

A. Increases
B. Decreases
C. Oscillates rapidly
D. Becomes pressure-fixed

If tissue metabolism remains low for a prolonged period, tissue vascularity generally:

A. Becomes unchanged
B. Decreases
C. Increases
D. Doubles abruptly

In premature infants, excess oxygen initially causes retinal vessels to:

A. Overgrow immediately
B. Arterialize rapidly
C. Stop growing and regress
D. Dilate but remain intact

When the infant is removed from excess oxygen, the subsequent retinal vessel overgrowth is driven mainly by:

A. Sudden glucose excess
B. Sudden oxygen deficiency
C. High venous pressure
D. Endothelin excess

The first listed step of angiogenesis is:

A. Capillary loop perfusion
B. Tube-to-tube fusion
C. Basement membrane dissolution
D. Smooth muscle hypertrophy

After sprouting begins, endothelial cells next:

A. Reproduce and stream outward
B. Undergo apoptosis
C. Secrete endothelin
D. Constrict donor vessels

During angiogenesis, the endothelial cords then:

A. Become lymphatics
B. Fold into tubes
C. Undergo fibrosis
D. Form arterioles first

A later step in angiogenesis occurs when a new tube:

A. Undergoes thrombosis
B. Loses its lumen
C. Regresses completely
D. Connects with another tube

The final listed result of angiogenesis is:

A. A perfused capillary loop
B. Arterial wall calcification
C. Venous valve formation
D. Immediate vasoconstriction

Which substance is a plasminogen fragment that inhibits angiogenesis?

A. Endothelin
B. Angiogenin
C. Angiostatin
D. Histamine

Endostatin is best described as an:

A. Endothelial vasodilator
B. Anti-angiogenic peptide
C. Adrenergic cotransmitter
D. Platelet growth factor

Vascularity is primarily determined by the tissue’s:

A. Resting venous pressure
B. Lowest oxygen tension
C. Mean capillary density
D. Maximum flow requirement

After exercise-induced vascularity has developed, the extra vessels not currently needed usually:

A. Remain vasoconstricted
B. Thrombose permanently
C. Regress within minutes
D. Stay maximally open

A patient develops gradual reperfusion of ischemic tissue after an arterial occlusion because preexisting vascular connections enlarge and later new channels grow. This process is called:

A. Active hyperemia
B. Collateral circulation
C. Vasomotion
D. Reactive vasospasm

Immediately after a vessel becomes blocked, the first stage of collateral development consists primarily of:

A. New capillary sprouting
B. Fibrotic wall thickening
C. Dilation of small vascular loops
D. Venous arterialization

The earliest dilation of preexisting collateral loops after arterial blockage is driven mainly by:

A. Sympathetic discharge
B. Metabolic factors
C. Endothelin release
D. Fibroblast activation

In the second stage of collateral development over hours to days, which change predominates?

A. Vessel calcification
B. Greater vessel opening
C. Wall fibrosis only
D. Capillary regression

Over months after an occlusion, collateral vessels typically:

A. Undergo thrombosis
B. Remain minimally dilated
C. Form multiple channels
D. Lose smooth muscle

In most tissues, small arteries and arterioles respond within seconds to increased arterial pressure by:

A. Vasodilation
B. Capillary recruitment
C. Venous pooling
D. Vasoconstriction

The rapid vasoconstrictor response of small resistance vessels to increased pressure primarily serves to:

A. Increase lymph formation
B. Autoregulate tissue blood flow
C. Promote angiogenesis
D. Raise venous return

Inward eutrophic remodeling is best defined as:

A. Wall thickening with lumen gain
B. Cell rearrangement around smaller lumen
C. Medial hypertrophy with fibrosis
D. Endothelial loss with dilation

Which statement best describes inward eutrophic remodeling?

A. Wall area stays unchanged
B. Collagen markedly increases
C. Lumen enlarges progressively
D. Media becomes hypertrophic

Large vessels that do not constrict when pressure rises are most likely to undergo:

A. Inward eutrophic remodeling
B. Outward remodeling
C. Hypertrophic remodeling
D. Reactive hyperemia

Which change is characteristic of hypertrophic remodeling?

A. Smaller wall cross-sectional area
B. Increased wall cross-sectional area
C. Loss of vascular smooth muscle
D. Decreased collagen synthesis

Hypertrophic remodeling helps vessels adapt to high blood pressure mainly by:

A. Increasing vessel compliance
B. Reinforcing wall strength
C. Lowering shear stress
D. Dilating the lumen widely

Which vein is commonly harvested for coronary artery bypass grafting?

A. Basilic vein
B. Saphenous vein
C. Femoral vein
D. Cephalic vein

A direct connection between a large artery and a large vein that bypasses resistance vessels and capillaries is called a:

A. Sinusoid
B. Collateral loop
C. Anastomotic plexus
D. Fistula

On the arterial side of an arteriovenous fistula, the expected vascular response is:

A. Outward remodeling
B. Inward remodeling
C. Hypertrophic constriction
D. Capillary rarefaction

On the venous side of an arteriovenous fistula, the expected remodeling pattern is:

A. Inward eutrophic remodeling
B. Outward hypertrophic remodeling
C. Pure vasoconstrictive remodeling
D. No remodeling occurs

Between epinephrine and norepinephrine, which is the more potent vasoconstrictor?

A. Epinephrine
B. They are equal
C. Norepinephrine
D. Depends on calcium only

Which statement about epinephrine’s vascular effect is most accurate?

A. It is always stronger than NE
B. It may cause slight vasodilation
C. It only constricts veins
D. It blocks alpha receptors

A patient with severe hypotension develops a hormone-mediated rise in total peripheral resistance along with decreased renal sodium and water excretion. Which mediator best fits?

A. Bradykinin
B. Histamine
C. Angiotensin II
D. Kallidin

The direct vascular effect of angiotensin II is primarily:

A. Small-arteriole venodilation
B. Small-arteriole vasoconstriction
C. Capillary leak
D. Endothelial NO release

Which mediator is most associated with arteriolar dilation and increased capillary permeability that may produce edema?

A. Angiotensin II
B. Bradykinin
C. Vasopressin
D. Endothelin

Regulation of blood flow in skin, salivary glands, and GI glands is especially associated with:

A. Bradykinin
B. Angiotensin II
C. Vasopressin
D. Norepinephrine

In inflamed tissue, kinins mainly regulate:

A. Conduction velocity and capillary leakage
B. Blood flow and capillary leakage
C. Platelet count and capillary leakage
D. Hemoglobin affinity and capillary leakage

Which acid-base state is most associated with arteriolar vasoconstriction?

A. Acidosis
B. Alkalosis
C. Hypercapnia
D. Lacticemia

Which group contains anions specifically noted to cause vasodilation?

A. Sulfate and phosphate
B. Bicarbonate and chloride
C. Acetate and citrate
D. Lactate and pyruvate