Phys 24 Flashcards

What does circulatory shock mean?

A) Localized excess perfusion

B) Generalized inadequate tissue blood flow

C) Isolated hypertension crisis

D) Venous obstruction only

Tissue damage in circulatory shock occurs mainly because too little what reaches cells?

A) Oxygen and nutrients

B) Carbon dioxide and wastes

C) Lymph and proteins

D) Hormones and enzymes

Two major categories can severely reduce cardiac output. One is cardiac abnormalities that:

A) Increase afterload only

B) Decrease pumping ability

C) Improve venous tone

D) Raise arterial oxygen

The other major category lowering cardiac output is factors that decrease:

A) Coronary pressure

B) Arterial compliance

C) Venous return

D) Pulmonary diffusion

Why does reduced venous return lower cardiac output?

A) The heart cannot pump absent inflow

B) Arteries constrict too rapidly

C) Ventricles stop depolarizing

D) Capillaries become impermeable

The most common cause of decreased venous return is reduced:

A) Blood volume

B) Heart rate

C) Blood viscosity

D) Hematocrit

Venous return can fall because of decreased vascular:

A) Resistance

B) Elasticity

C) Tone

D) Frequency

Loss of venous tone is especially important in which vascular compartment?

A) Pulmonary capillaries

B) Venous reservoirs

C) Coronary arteries

D) Cerebral arterioles

Another major cause of reduced venous return is:

A) Excess lymph flow

B) Valve calcification

C) Obstruction to flow

D) Elevated plasma proteins

Obstruction causing shock is especially dangerous when it lies in the pathway of venous return to the:

A) Kidneys

B) Brain

C) Heart

D) Lungs

A patient may be in shock despite normal or increased cardiac output if metabolic rate is:

A) Excessively low

B) Excessively high

C) Completely absent

D) Equal to resting

Normal or high cardiac output can still be inadequate in shock if tissue perfusion patterns are:

A) Abnormally distributed

B) Fully autoregulated

C) Excessively venous

D) Entirely coronary

In distributive perfusion failure, much of the cardiac output passes through vessels that do not:

A) Return blood to veins

B) Remove clot burden

C) Supply local tissue nutrition

D) Contain smooth muscle

All cases of shock lead to inadequate delivery of what to critical tissues?

A) Nutrients

B) Catecholamines

C) Bicarbonate

D) Platelets

Shock also impairs removal of cellular:

A) Hormones

B) Waste products

C) Growth factors

D) Clotting factors

A patient may be in severe shock and still have nearly normal arterial pressure because of powerful:

A) Renal hormones

B) Nervous reflexes

C) Plasma proteins

D) Coronary shunts

In most types of shock, especially severe blood loss, arterial pressure usually:

A) Rises as output falls

B) Falls with cardiac output

C) Stays fully unchanged

D) Exceeds baseline markedly

During hemorrhagic shock, arterial pressure usually decreases:

A) More than cardiac output

B) Less than cardiac output

C) Before blood loss begins

D) Only after therapy

Once shock reaches a critical severity, the shock itself tends to produce:

A) Automatic recovery

B) More shock

C) Isolated hypertension

D) Pure bradycardia

The earliest major stage of shock is the:

A) Irreversible stage

B) Progressive stage

C) Nonprogressive stage

D) Terminal fibrillation

The nonprogressive stage of shock is also called the:

A) Compensated stage

B) Decompensated stage

C) Obstructive stage

D) Cardiogenic stage

In compensated shock, normal compensatory mechanisms can eventually produce:

A) Renal failure

B) Full recovery

C) Pulmonary edema

D) Irreversible ischemia

The second major stage of shock is the:

A) Compensated stage

B) Progressive stage

C) Reversible stage

D) Hypertrophic stage

Without what does progressive shock steadily worsen toward death?

A) Sleep

B) Therapy

C) Nutrition

D) Ventilation

The final major stage of shock is the:

A) Hyperdynamic stage

B) Irreversible stage

C) Prodromal stage

D) Vasodilated stage

The most common cause of hypovolemic shock is:

A) Burns

B) Diarrhea

C) Hemorrhage

D) Sepsis

Hemorrhage lowers venous return primarily by decreasing the circulatory:

A) Filling mean systemic filling pressure

B) Arterial oxygen content

C) Ventricular compliance

D) Coronary resistance

After hemorrhage, both cardiac output and arterial pressure generally:

A) Increase together

B) Decrease together

C) Remain unchanged

D) Diverge opposite ways

The fall in arterial pressure after hemorrhage, along with reduced thoracic vascular pressures, triggers strong:

A) Parasympathetic reflexes

B) Sympathetic reflexes

C) Metabolic reflexes

D) Cushing reflexes

Which pairing is correct for shock with normal cardiac output?

A) High output plus perfect nutrition

B) High metabolism or maldistributed perfusion

C) Low metabolism and high preload

D) Bradycardia and hypertension

Which factor below is a venous-return problem rather than a primary pump problem?

A) Myocardial infarction

B) Cardiac tamponade

C) Diminished blood volume

D) Ventricular fibrillation

After hemorrhage, sympathetic reflexes increase total peripheral resistance primarily by causing systemic arterioles to:

A) Dilate widely

B) Constrict

C) Collapse completely

D) Lose tone

The major hemodynamic result of widespread arteriolar constriction during hemorrhage is:

A) Decreased venous return

B) Increased total peripheral resistance

C) Decreased arterial pressure

D) Increased capillary filtration

A second major sympathetic response to blood loss is constriction of the:

A) Coronary arteries only

B) Pulmonary capillaries

C) Veins and venous reservoirs

D) Cerebral arterioles

Why is venoconstriction especially important during hemorrhage?

A) It lowers arterial stiffness

B) It preserves venous return

C) It abolishes afterload

D) It reduces heart rate

The third major effect of sympathetic reflex activation in hemorrhage is a marked increase in:

A) Lymphatic flow

B) Heart activity

C) Coronary sinus pressure

D) Atrial compliance

Sympathetic reflexes during hemorrhage are geared more toward maintaining:

A) Cardiac output

B) Arterial pressure

C) Plasma osmolarity

D) Coronary flow

Which compensatory change most directly helps keep cardiac output from falling too much after blood loss?

A) Arteriolar constriction

B) Venous constriction

C) Capillary filtration

D) Bradycardia

Recovery from moderate shock depends largely on circulatory negative feedback mechanisms that attempt to restore:

A) Coronary flow and preload

B) Heart rate and renin

C) Cardiac output and arterial pressure

D) Capillary pressure and hematocrit

Which reflex is an early negative feedback mechanism that strongly stimulates the sympathetic circulation after hemorrhage?

A) Bainbridge reflex

B) Baroreceptor reflex

C) Cushing reflex

D) Bezold-Jarisch reflex

The baroreceptor reflex helps recovery from shock mainly by producing:

A) Parasympathetic withdrawal

B) Powerful sympathetic stimulation

C) Coronary venodilation

D) Decreased vascular tone

Compared with the baroreceptor reflex, the CNS ischemic response produces:

A) Less sympathetic output

B) No vascular effect

C) Even more powerful sympathetic stimulation

D) Pure vagal discharge

The CNS ischemic response is usually not activated significantly until:

A) Cardiac output doubles

B) Arterial pressure is very low

C) Venous tone is normal

D) Renin secretion ceases

Reverse stress-relaxation helps recover from blood loss by causing vessels to:

A) Dilate around low volume

B) Contract around low volume

C) Lose smooth muscle tone

D) Open capillary beds widely

The functional purpose of reverse stress-relaxation in shock is to allow the available blood volume to:

A) More adequately fill the circulation

B) Preferentially enter the lungs

C) Bypass venous reservoirs

D) Increase tissue edema

A renal compensatory response in hemorrhagic shock is increased secretion of:

A) Nitric Oxide

B) ANP

C) Renin

D) Erythropoietin

Increased renin secretion during shock promotes formation of:

A) Bradykinin

B) Angiotensin II

C) Nitric oxide

D) Endothelin

Angiotensin II helps compensate for shock primarily by:

A) Dilating peripheral arterioles

B) Constricting peripheral arterioles

C) Lowering venous tone

D) Increasing capillary leak

A second major benefit of angiotensin II in shock is that it promotes:

A) Increased renal water and salt loss

B) Decreased renal water and salt output

C) Immediate plasma protein synthesis

D) Pulmonary vasodilation

Compensation prioritizes:

A) Cardiac output over pressure

B) Pressure over cardiac output

C) Coronary flow over pressure

D) Oxygen extraction over tone

Which statement best explains why arterial pressure can be preserved despite substantial blood loss?

A) Sympathetic reflexes strongly defend pressure

B) Coronary arteries autoregulate fully

C) Blood viscosity rises immediately

D) The kidneys replace volume instantly

Which of the following is not one of the three immediate major effects of sympathetic reflexes in hemorrhage?

A) Arteriolar constriction

B) Venous constriction

C) Marked tachycardia

D) Capillary protein synthesis

Which posterior pituitary hormone helps compensate for shock?

A) Oxytocin

B) Vasopressin

C) Aldosterone

D) Renin

Vasopressin helps restore circulation in shock mainly by:

A) Dilating arteries only

B) Constricting veins only

C) Constricting arterioles and veins

D) Lowering renal water reabsorption

A major renal effect of vasopressin in shock is:

A) Increased water retention

B) Increased sodium wasting

C) Increased bicarbonate loss

D) Decreased thirst

In shock, increased secretion of epinephrine and norepinephrine comes primarily from the:

A) Adrenal cortex

B) Adrenal medullae

C) Posterior pituitary

D) Juxtaglomerular cells

Adrenal medullary catecholamines help compensate for shock by causing peripheral vessels to:

A) Dilate and pool blood

B) Constrict and support pressure

C) Collapse and clot

D) Leak and swell

A second major compensatory effect of adrenal medullary catecholamine release in shock is increased:

A) Heart rate

B) Capillary permeability

C) Plasma potassium

D) Coronary thrombosis

Which is a mechanism that helps restore blood volume during shock?

A) Decreased thirst

B) Intestinal fluid absorption

C) Increased urine output

D) Reduced salt appetite

Shock compensation includes movement of fluid into the blood from the:

A) Alveoli

B) Interstitial spaces

C) Lymph nodes

D) Pericardium

Behavioral compensation for shock includes increased:

A) Thirst and salt appetite

B) Hunger for sugar

C) Need for sleep

D) Sweating and urination

Which of the following is not part of blood-volume restoration in shock?

A) Intestinal absorption

B) Fluid shift into capillaries

C) Renal conservation

D) Coronary vasospasm

When arterial pressure falls sufficiently low in shock, nutrition of the myocardium becomes inadequate because:

A) Cerebral flow rises too high

B) Coronary blood flow falls

C) Pulmonary veins collapse first

D) Aortic oxygen content doubles

A major feature of progressive shock, regardless of cause, is progressive:

A) Cardiac improvement

B) Cardiac deterioration

C) Renal hypertrophy

D) Arterial dilation

After about 10 to 15 minutes of markedly diminished brain blood flow, the vasomotor center becomes:

A) Hyperactive

B) Depressed

C) Hypertrophied

D) Insensitive to CO2

Once the vasomotor center is severely depressed in shock, there is:

A) More sympathetic discharge

B) No further sympathetic evidence

C) Selective vagal arrest

D) Immediate recovery

As progressive shock continues, many very small vessels develop:

A) Aneurysms

B) Blockage

C) Vasodilation

D) Elastic recoil

Local tissue metabolism during low-flow shock causes accumulation of which two major acids?

A) Sulfuric and phosphoric

B) Carbonic and lactic

C) Uric and hydrochloric

D) Acetic and pyruvic

The rising local acidity in shock is mainly due to ongoing tissue metabolism despite:

A) High blood flow

B) Low blood flow

C) Hyperoxia

D) High pH

Acid buildup and ischemic breakdown products promote local blood:

A) Hemolysis

B) Agglutination

C) Oxygenation

D) Dilution

Local blood agglutination in shock leads directly to formation of:

A) Large emboli

B) Minute clots

C) Coronary aneurysms

D) Lymphatic plugs

The term for blood that becomes difficult to move through the microvasculature because cells stick together is:

A) Foamy blood

B) Sludged blood

C) Deoxygenated blood

D) Viscous plasma

After many hours of capillary hypoxia, capillary permeability typically:

A) Decreases

B) Increases

C) Normalizes

D) Oscillates unpredictably

In late shock, increased capillary permeability causes fluid to:

A) Enter arteries

B) Transude into tissues

C) Remain intravascular

D) Enter lymph only

Shock may trigger release of toxic mediators such as histamine, serotonin, and:

A) Tissue enzymes

B) Platelet factor IV

C) Immunoglobulins

D) Bile acids

A toxic factor released from dead gram-negative bacteria in the intestines is:

A) Exotoxin

B) Endotoxin

C) Enteropeptidase

D) Hemolysin

Circulating endotoxin in shock causes cellular metabolism to:

A) Decrease appropriately

B) Increase despite poor nutrition

C) Stop completely

D) Shift only to fat oxidation

A particularly important effect of endotoxin in shock is:

A) Coronary dilation

B) Cardiac depression

C) Increased renal filtration

D) Decreased lactate production

As shock becomes severe, generalized cellular deterioration is especially prominent in the:

A) Liver

B) Spleen

C) Thyroid

D) Pancreas

In severe shock, which ions accumulate inside cells?

A) Potassium and bicarbonate

B) Sodium and chloride

C) Calcium and magnesium

D) Hydrogen and phosphate

During cellular deterioration in shock, which ion is lost from cells?

A) Sodium

B) Chloride

C) Potassium

D) Calcium

The ionic shifts of shock cause cells to:

A) Shrink

B) Swell

C) Divide

D) Calcify

In shock, which organelle’s activity becomes severely depressed in liver cells and many other tissues? This organelle doesn't rupture, however:

A) Ribosomal

B) Golgi

C) Lysosomal

D) Mitochondrial

Widespread intracellular deterioration in shock is worsened when which organelles rupture?

A) Peroxisomes

B) Lysosomes

C) Nuclei

D) Centrioles

When lysosomes break open in shock, they release intracellular:

A) Hydrolases

B) Catecholamines

C) Lipoproteins

D) Hemoglobin

Which process best explains progression of shock despite initial compensation?

A) Positive feedback worsening perfusion

B) Complete restoration of preload

C) Permanent baroreceptor activation

D) Selective cerebral vasodilation

Which event most directly links severe hypotension to later myocardial failure in progressive shock?

A) Increased coronary flow

B) Decreased coronary nutrition

C) Renal sodium excretion

D) Increased AV nodal firing

In the last stages of shock, cellular metabolism of which nutrient becomes greatly depressed?

A) Lactate

B) Glucose

C) Ketones

D) Creatine

Around which end of capillaries does the greatest nutritive deficiency occur in shock?

A) Arterial end

B) Venous end

C) Midcapillary zone

D) Lymphatic end

Progressive pulmonary deterioration after shock causing respiratory distress days later is called:

A) COPD

B) Shock lung syndrome

C) Blue bloater lung

D) Flash edema

In irreversible shock, essentially all cellular stores of what high-energy compound are depleted?

A) Creatine phosphate

B) Glycogen

C) NADH

D) Lactate

In irreversible shock, ATP is progressively degraded to ADP, AMP, and eventually:

A) Inosine

B) Creatine

C) Adenosine

D) Pyruvate

Why are depleted cellular high-energy phosphate stores hard to restore in irreversible shock?

A) New adenosine is slow to make

B) Mitochondria overproduce acids

C) Cells lose all glucose

D) Kidneys waste all phosphate

Intestinal obstruction can cause severe shock mainly by reducing:

A) Cardiac contractility

B) Plasma volume

C) Coronary flow

D) Arterial compliance

In intestinal obstruction, bowel distention partly blocks venous flow in the intestinal:

A) Lumen

B) Walls

C) Arteries

D) Lymphatics

Venous blockage in intestinal obstruction increases intestinal capillary:

A) Blood filtration

B) Pressure

C) Osmolality

D) Filtration fraction

Elevated intestinal capillary pressure causes fluid to leak into the intestinal walls and the:

A) Pleural cavity

B) Intestinal lumen

C) Pericardium

D) Portal vein

Because leaked intestinal fluid is protein-rich, intestinal obstruction reduces total plasma:

A) Sodium

B) Bicarbonate

C) Protein

D) Chloride

The protein-rich fluid loss of intestinal obstruction ultimately reduces plasma:

A) Osmolarity

B) Volume

C) Potassium

D) Glucose

Severe burns can precipitate hypovolemic shock chiefly by causing loss of:

A) Whole blood

B) Plasma through skin

C) Lymph through nodes

D) CSF through wounds

Compared with hemorrhagic shock, hypovolemic shock is especially characterized by increased blood:

A) Oxygen content

B) Viscosity

C) Sodium

D) pH

The increased blood viscosity of hypovolemic shock results mainly from increased red cell:

A) Production

B) Destruction

C) Concentration

D) Deformability

Shock from dehydration can result from excessive:

A) Sweating

B) Hemolysis

C) Insulin

D) Salivation

Shock from dehydration can result from severe diarrhea or:

A) Constipation

B) Vomiting

C) Aspiration

D) Flatulence

Shock from dehydration can also result from excess fluid loss by the:

A) Skin

B) Kidneys

C) Lungs

D) Spleen

Inadequate intake of fluid and what else can lead to dehydration shock?

A) Proteins

B) Electrolytes

C) Lipids

D) Vitamins

Destruction of the adrenal cortices predisposes to dehydration shock because of loss of:

A) Cortisol

B) Aldosterone

C) Epinephrine

D) ADH

Sudden loss of vasomotor tone causing massive venous dilation is called:

A) Cardiogenic shock

B) Neurogenic shock

C) Septic shock

D) Obstructive shock

Which can cause neurogenic shock by loss of vasomotor tone?

A) Deep general anesthesia

B) Hyperthyroidism

C) Mitral stenosis

D) Polycythemia

Which can cause neurogenic shock by interrupting sympathetic tone?

A) Portal hypertension

B) Spinal anesthesia

C) Asthma

D) Renal failure

Which central cause may precipitate neurogenic shock?

A) Brain damage

B) Liver rupture

C) Pleural fibrosis

D) GI bleeding

In severe allergic reactions, which mediator can sharply reduce venous return and cause rapid shock?

A) Bradykinin

B) Histamine

C) Dopamine

D) Acetylcholine

Bacterial infection spread through the bloodstream to many tissues causing extensive damage is called:

A) Neurogenic shock

B) Septic shock

C) Cardiogenic shock

D) Anaphylactic shock

Most cases of septic shock are caused first by Gram-___ organisms.

A) Negative

B) Positive

C) Variable

D) Neutral

After Gram-positive bacteria, septic shock is commonly caused by endotoxin-producing Gram-___ bacteria.

A) Positive

B) Negative

C) Variable

D) Acid-fast

A classic cause of septic shock is peritonitis from spread of infection from the uterus and:

A) Ovaries

B) Fallopian tubes

C) Cervix

D) Vagina

Peritonitis leading to septic shock may follow rupture of the:

A) Gastrointestinal system

B) Pulmonary tree

C) Coronary sinus

D) Biliary duct

Generalized septic shock may arise from spread of which type of peripheral infection?

A) Skin infection

B) Joint infection

C) Retinal infection

D) Thyroid infection

A common skin-source organism leading to septic shock is:

A) Candida or staph

B) Strep or staph

C) E. histolytica

D) Mycoplasma

Generalized gangrenous infection causing septic shock is classically due to:

A) Tetanus bacilli

B) Gas gangrene bacilli

C) Tubercle bacilli

D) Diphtheria bacilli

Gas gangrene infection spreads first through peripheral tissues and then to internal organs, especially the:

A) Pancreas

B) Liver

C) Brain

D) Spleen

Another important source of septic shock is infection entering the blood from the:

A) kidney or urinary tract

B) liver or upper airway

C) kidney or bone marrow

D) liver or small bowel

Infection spreading from the urinary tract and causing septic shock is often due to:

A) Pneumococcus

B) Colon bacilli

C) Staphylococci

D) Clostridia

Which mechanism best explains hypovolemia in intestinal obstruction?

A) Fluid shifts into bowel

B) Myocardial depression

C) Arterial rupture

D) Renal vasodilation

The best therapy for shock caused by hemorrhage is usually:

A) Plasma

B) Electrolyte solution

C) Whole blood transfusion

D) Dextran

If shock is caused primarily by plasma loss, the best therapy is administration of:

A) Whole blood

B) Plasma

C) Heparin

D) Streptokinase

When dehydration is the cause of shock, the most appropriate treatment is an:

A) Appropriate electrolyte solution

B) Immediate plasma exchange

C) Whole blood transfusion

D) Pure glucose infusion

If cardiac output remains adequate, the body can usually tolerate a hematocrit decrease to about:

A) Three fourths normal

B) Half normal

C) One fourth normal

D) One tenth normal

A plasma substitute must contain molecules large enough to exert:

A) Hydrostatic pressure

B) Colloid osmotic pressure

C) Pulse pressure

D) Filtration pressure

Why are dextrans useful as plasma substitutes?

A) They increase hematocrit and provide colloid osmotic effect

B) They remain intravascular and provide colloid osmotic effect

C) They stimulate erythropoiesis and provide colloid osmotic effect

D) They directly constrict arterioles and provide colloid osmotic effect

Dextrans can replace plasma proteins mainly because they do not pass through:

A) Glomerular slits

B) AV valves

C) Capillary pores

D) Coronary sinuses

Sympathomimetic drugs such as epinephrine and norepinephrine are most useful in which two shock states?

A) Hemorrhagic and cardiogenic

B) Septic and hypovolemic

C) Neurogenic and anaphylactic

D) Obstructive and cardiogenic

You should put patients in a head-down position beacuse it improves shock by increasing:

A) Coronary resistance

B) Venous return

C) Capillary leakage

D) Pulmonary pressure

The first essential maneuver in treatment of many types of shock is the:

A) Upright position

B) Head-down position

C) Left lateral position

D) Reverse Trendelenburg

Glucocorticoids are often given in severe shock because they may increase late-stage cardiac:

A) Compliance

B) Strength

C) Automaticity

D) Oxygen extraction

A second reason glucocorticoids are used in severe shock is that they stabilize:

A) Mitochondria

B) Ribosomes

C) Lysosomes

D) Nuclei

By stabilizing lysosomes, glucocorticoids help prevent further cellular:

A) Deterioration

B) Hypertrophy

C) Vasodilation

D) Oxygenation

A third proposed benefit of glucocorticoids in severe shock is support of cellular metabolism of:

A) Ketones

B) Glucose

C) Lactate

D) Creatine

Administration of what anticoagulant before cardiac arrest has been shown to increase brain survivability?

A) Warfarin

B) Heparin

C) Aspirin

D) Clopidogrel

Which fibrinolytic agent, if given before cardiac arrest, may also prolong brain survivability?

A) Alteplase

B) Urokinase

C) Tenecteplase

D) Streptokinase

Why is an adequate cardiac output important when hematocrit falls?

A) It compensates for lower oxygen carrying capacity

B) It prevents capillary protein loss

C) It raises colloid osmotic pressure

D) It eliminates need for plasma

Which statement about early septic shock is most accurate?

A) Collapse is always immediate

B) Infection signs may predominate first

C) Hemorrhage is the cause

D) Bradycardia is universal

Which agent class is especially useful for anaphylactic shock?

A) Sympathomimetics

B) Plasma substitutes

C) Anticoagulants

D) Pure crystalloids only

Which outcome is most feared after prolonged total circulatory arrest?

A) Aortic stenosis

B) Permanent brain damage

C) Mitral regurgitation

D) Polycythemia

______ fibrillation can cause circulatory arrest

Local accumulation of carbonic/lactic acid is present in circulatory shock, meaning there is _____ pH

A patient with severe hemorrhagic shock receives a blood transfusion. When is restoration of circulation most likely to reverse the shock?

A. After irreversible myocardial injury
B. Before irreversible cardiac changes
C. After ATP stores disappear
D. After prolonged circulatory arrest

Head-down positioning is especially useful for improving venous return in which two forms of shock?

A. Cardiogenic and septic
B. Septic and anaphylactic
C. Hemorrhagic and neurogenic
D. Cardiogenic and obstructive

During irreversible shock, ATP is degraded to adenosine, which can ultimately be converted into:

A. Creatinine
B. Bilirubin
C. Uric acid
D. Lactate

Which finding most strongly suggests septic rather than uncomplicated hypovolemic shock?

A. High fever
B. Reduced venous return
C. Low tissue perfusion
D. Metabolic acidosis