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Physiology 101-200 Flashcards

1
Q

which of the following processes will account for the excessive uncontrolled muscle rigidity seen in Malignant Hyperthermia ?
A. Increase activity of the SERCa pump
B. Delayed closure of the ryanodine receptors in the skeletal muscle
C. decrease level of voltage gated Na and K channels in the Transverse tubules
D. decrease activity of the DHPR
E. none of the above

A

B
prolonged opening of the ryanodine receptors will promote excessive Calcium entry in the sarcoplasm leading to stimulation of sarcoplasmic reticulum to release excessive amounts of ca for muscular contraction leadin to rigidity. The other choices will lead to decrease ca level in the sarcoplasm. Guyton 11th ed p 89-91

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2
Q 
what kind of transport process used by non exercising skeletal muscles for glucose uptake ? 
A. Simple diffusion 
B. Secondary active transport 
C. Counter or exchange transport 
D. Facilitated diffusion 
E. None of the above
A

D
in the presence of insulin, glut 4 receptors are translocated in to sarcoplasmic membrane to promote glucose uptake via facilitated diffusion. Guyton 11th ed p 50

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3
Q

which of the following scenario will result to tetanic contraction of the cardiac muscle ?
A. Increased extracellular calcium ions
B. Extreme hyperthermia
C. Increase catecholamine surge
D. Increase extracellular potassium ions
E. All of the above

A

A
heart muscle is dependent on extracellular calcium ions for its contraction. Increasing the latter in an high proportion will lead to tetanic contraction of the heart or ventricular fibrillation. Guyton 11 th ed p 114-115

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4
Q

A 45 y/o male, hypertensive an diabetic went for general check up. PE was unremarkable. 12L ECG was done showing normal sinus rhythm however there were occasional inverted P waves noted after the QRS complex. What is the most likely reason for this tracing abnormality?
A. atrial fibrillation
B. supra AV nodal Premature contraction
C. premature contraction coming from the his bundle
D. atrial premature contraction
E. all of the above

A

C
if the origin of cardiac impulse is below the AV node, the action potential will travel towards the atria as well as to the ventricles. Since there would be much delay travelling towards the AV node than to the ventricles, inverted P waves will be seen after the QRS complex. atrial fibrillation leads to no discernible p waves with an irregularly irregular pattern of QRS complex. Supranodal premature contraction will have inverted p waves prior to QRS. Know how to read ECG and the basis of each deflections. guyton 11th ed p 150- 153

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5
Q

increasing the reynolds number or the turbulence in an arteriole will result in the following consequence?
A. Induction of Nitric oxide synthase
B. Decrease prostacylin release
C. Increase renin and angiotensin levels
D. Decrease cGMP
E. none of the above

A

A
turbulence or shear stress is one of the potent stimulus for release of Nitric oxide ( formerly known as EDRF) this is made through upregulation of NOS and increase levels of cGMP. Guyton 11th ed p 199-200

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6
Q 
the main determinant of blood flow in a non exercising skeletal muscle is? 
A. Arginine vasopressin 
B. Angiotensin II 
C. Local Metabolic rate 
D. Autonomic nervous system 
E. adenosine
A

C
the local metabolic needs of skeletal muscle, cardiac and nervous system is the main determinant of its blood flow level Guyton 11th ed p 195-196

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7
Q 
in which level in the vascular system wherein there is largest dissipation of arterial pressure during systole? 
A. Aorta 
B. Capillary venule junction 
C. arterioles 
D. Capillary level 
E. Medium size capillaries
A

C
arterioles are the primary determinant of arterial pressure gradient (particulary the arteriole -capillary junction). Guyton 11th ed p 162-163

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8
Q

which of the following scenario will lead to increased peritubular capillary fluid reabsorption?
A. Increase systolic blood pressure
B. Increase renal blood flow
C. Decrease filtration fraction
D. Intake of enalapril
E. Increase efferent arteriolar constriction

A

E
increasing the efferent arteriole resistance will consequently lead to decrease peritubular hydrostatic pressure resulting to increase in net fluid reabsorption. Use of ACEI will decrease the efferent arteriole constriction. Increase in BP will lead to increase in the glomerular pressure and peritubular capillary pressure. decreased filtration fraction increases the peritubular hydrostatic pressure leading to decrease reabsorption. guyton 11th ed 339-340

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9
Q

During Diabetic ketoacidosis, hydrogen ions actively secreted by the proximal tubule are associated with which physiologic process?
A. Excretion of ammonium ions
B. Reabsorption of bicarbonate
C. Reabsorption of potassium ions
D. reabsorption of phosphae ions E. all of the above

A

B
part of the compensatory response of the kidney during acidosis is to remove hydrogen ions and consequently reabsorb bicarbonate ions in the proxima tubule. ( SIMILAR TO PREVIOUS BOARD EXAM CONCEPT/PRINCIPLE) guyton 11th ed page 306-307

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10
Q 
which of the following scenario will promote urinary calcium excretion? 
A. Metabolic acidosis 
B. Increase plasma phosphate levels 
C. Intravascular Volume expansion 
D. Squamous cell carcinoma of the lungs 
E. None of the above
A

C
calcium reabsorption is directly proportional to water and sodium reabsorption. Therefore, increase in intravascular volume will lead to a decrease in Na,Ca and H20 reabsorption. Guyton 11th ed p 372

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11
Q 
deficiency in FXIII in the serum will lead to which of the following ? 
A. Prolonged PTT 
B. Prolonged PT 
C. Increase clotting time 
D. Decrease clot stability 
E. None of the above
A

D
polymerization of fibrin to form a clot requires the presence of fibrin stabilizing factor (FXIII). The latter is not required in the intrinsic and extrinsic pathway. Guyton 11th ed 467- 468

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12
Q

The increase in the alveolar ventilation during strenous aerobic exercise such as marathon is primarily due to which of the following changes?
A. cortical collateral impulses to the DRG (dorsal respiratory group)
B. Decrease in arterial pH
C. Decrease in arterial PO2
D. Decrease in venous PO2
E. All of the above

A

A
during prolonged aerobic exercise, the changes in the mean arterial PO2, PCO2 and pH are negligible. Venous system does not contain any pH or O2 sensors that could might affect the respiratory drive. Guyton 11th ed page 519-520

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13
Q 
Which of the following regions in the brain uses serotonin for suppression of pain pathways? 
A. Ventral tegmental area of tsai 
B. Nucleus raphes magnus 
C. Periaqueductal gray region 
D. Inferior olivary nucleus 
E. None of the above
A

B

A- dopaminergic neurons, Cenkephalin producing neurons, Dolivary nucleus nonspecific, related to auditory system.

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14
Q 
which is a correct pair of neurotransmitters used in fastpain and slow pain respectively at the dorsal horn synapse ? 
A. Glutamate/ substance P 
B. Acetycholine/substance P 
C. Acetylcholine/cGRP 
D. Serotonin/cGRP 
E. None of the above
A

A

refer to Guyton 11th ed p 600-601

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15
Q

Which of the followng occurs in rods/cones during phototransduction of light ?
A. Decrease phoshodiesterase activity
B. Increase cGMP hydrolysis
C. Decrease levels of transducin
D. Increase fraction of active voltage gated calcium channels
E. increase fraction of open voltage gated sodium channels

A

B
during phototransduction of light, there is an increase in the hydrolysis of cGMP leading to closure of Na channel. Failure of the Na to enter the rods leads to hyperpolarization. Guyton 11th ed page 630-631

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16
Q 
which of the following is not part of limbic cortex? 
A. Orbitofrontal gyrus 
B. Parahippocampal gyrus 
C. Paracentral lobule 
D. Cingulate gyrus 
E. None of the above
A

C
the components of limbic cortex are the following: orbitofrontal gyrus, cingulate gyrus, parahippocampal gyrus, and subcallosal gyrus

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17
Q 
damage to which of the following brain region leads to retrograde amnesia ? 
A. amygdala 
B. Dentate gyrus 
C. Hippocampus 
D. Subcallosal gyrus 
E. Thalamus
A

E

Guyton 11th ed p 726

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18
Q

Which of the following ions will increase in concentration when salivary secretion is maximally stimulated?
A. sodium
B. potassium
C. bicarbonate
D. Chloride
E. Ionic levels are constant regardless of secretion rate

A

A
during maximal salivary secretion, the rapid transit of saliva in the duct does not allow sufficient time for Na to be reabsorbed. Guyton 11th ed p 794

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19
Q 
how many hours it usually takes for a body to float secondary to drowning ? 
A. 16 hours 
B. 18 hours 
C. 22 hours 
D. 24 hours 
E. 48 hours
A

C
TAG upon reconstitution inside the intestinal epithelial cells will be transported to lacteals as a chylomicron. It will then travel to lymphatic system towards the thoracic duct entering the systemic circulation via the subclavian vein. Guyton 11th ed 815-816

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20
Q 
feeling of satiety after eating a high fat meal is secondary to which of the following changes? 
A. Increased cholecystokinin 
B. Increased ghrelin 
C. Decreased leptin 
D. Decreased peptide YY 
E. A and C
A

A
promotes sateity- increase levels of cholecystokinin, peptide YY and leptin. Promotes appetite - increase ghrelin and neuropeptide Y. Guyton11th ed p 868-870.

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21
Q

This statement describes the mean arterial pressure:
A. one-third of the sum of diastolic and systolic pressures
B. average of systolic and diastolic pressures
C. determined about 40% by diastolic and 60% by systolic pressure
D. average of arterial pressures measured millisecond by millisecond over a period of time

A

D
MAP = 1/3(S+2D). MAP is determined 40% by systolic and 60% by diastolic pressure. Guyton Medical Physiology 11th edition p.176

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22
Q

The following are consistent with acute control of local blood flow, except:
A. adenosine accumulation affecting blood flow regulation
B. effect of an increase in concentration of CO2 and H+ on cerebral vessels
C. stretch-induced vascular depolarization, causing vasoconstriction
D. tubuloglomerular feedback
E. development of collateral circulation

A

E
Collateral circulation development is a phenomenon of long-term (not acute) local blood flow regulation. Guyton Medical Physiology 11th edition pp.198-200

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23
Q

True regarding the baroreceptor reflex:
A. Signals from carotid baroreceptors are trasmitted through the vagus nerves.
B. Signals from aortic baroreceptors are transmitted to the tractus solitarius of the medulla.
C. The carotic baroreceptors are stimulated by pressures 0-50/60 mmHg.
D. The baroreceptors respond much more to a stationary pressure.
E. When signals have reached the brainstem, secondary signals stimulate the vasoconstrictor center

A

B
Signals from the carotid baroreceptors are transmitted through the Hering’s nerves to glossopharyngeal nerves. Signals from both carotic and aortic baroreceptors are transmitted to the tractus solitarius of the medulla. The carotid baroreceptors are not stimulated at all by pressures 0-50/60, as they respond progressively more rapidly above these levels and reach a max of 180 mmHg. The baroreceptors respond much more to a rapidly changing pressure. When signals have reached the brainstem, secondary signals inhibit the vasocontrictor center. Guyton Medical Physiology 11th edition pp.209-210

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24
Q

What causes the 4th heart sound?
A. inrush of blood into ventricles after atrial contraction
B. closure of the AV valves
C. closure of the semilunar valves
D. inrush of blood into the great valves after ventricular contraction
E. inrush of blood through stenosed valves

A

A

B refers to S1. C refers to S2. Guyton Medical Physiology 11th edition p.270

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25
Q

True of heart sounds:
A. S2 is slightly longer in duration than S1
B. S2 has a lower frequency than S1
C. S1 is caused by closure of the aortic valve
D. S2 is caused by oscillation of blood between walls of ventricles
E. AV valves are more taut than semilunar valves.

A

A
S2 has a higher frequency than S1, due to the more taut semilunar valves, and the great elastic coefficient of taut arterial walls. S2 is slightly longer in duration than S1. Guyton Medical Physiology 11th edition p.270

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26
Q 
Which valve is the second most seriously damaged in rheumatic fever? 
A. mitral 
B. tricuspid 
C. aortic 
D. pulmonic
A

A
Mitral valve is the most seriously damaged valve in rheumatic fever, followed by aortic valve. Guyton Medical Physiology 11th edition p.271

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27
Q

Not true regarding the glomerular capillary membrane?
A. It is composed of 3 major layers.
B. Albumin is an example of a substance with a filterability of 1.
C. The capillary endothelium is endowed with fenestrae.
D. It is much thicker than other capillaries’.
E. Both basement membrane and podocytes have negative charges.

A

B
Water, sodium, glucose, and inulin are examples of substances with a filterability of 1. Guyton Medical Physiology 11th edition p.316-317

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28
Q

Raises GFR, except:
A. modest efferent constriction
B. increased glomerular capillary filtration coefficient
C. increased arterial pressure
D. decreased resistance of the afferent arterioles
E. none of the above

A

E

Guyton Medical Physiology 11th edition pp.318-320

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29
Q

True of intrinsic pathway for initiating clotting:
A. begins with a traumatized vascular wall
B. begins with extravascular tissues that come into contact with blood
C. begins with trauma to the blood
D. B & C
E. all of the above

A

C
A & B refer to the extrinsic pathway for initiating clotting. Intrinsic pathway may also be initiated by the exposure of blood to collagen from traumatized vessel wall. Guyton Medical Physiology 11th edition p.462

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30
Q

Not true of the sneeze reflex:
A. afferent impulses pass through CNX
B. initiating stimulus is irritation in nasal passageways
C. uvula is depressed, as opposed to the cough reflex
D. none of the above
E. all of the above

A

A

Afferent impulses in the sneeze reflex pass through CNV. Guyton Medical Physiology 11th edition p.480

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31
Q

True regarding the Haldane effect:
A. quantitatively more important in promoting CO2 transport than is Bohr’s effect in promoting O2 transport
B. increased delivery of oxygen to tissues occurs when CO2 and H+ shifts the curve
C. CO2 diffuses to the lungs, decreasing the blood PCO2 and H+ concentration, shifting the curve to the left
D. CO2 in blood increases H2CO3, shifting the curve to the right
E. When CO2 binds with hemoglobin, O2 is released.

A

A

The other statements are regarding Bohr’s effect. Guyton Medical Physiology 11th edition p.511

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32
Q

True of the ventral respiratory group of neurons:
A. participate in the basic rhythmical oscillation that controls respiration
B. functions in both inspiration and expiration
C. active during normal quiet respiration
D. A & B
E. B & C

A

B
It is the dorsal respiratory group of neurons that participate in the basic rhythmical oscillation that controls respiration. The ventral respiratory group is inactive during quiet respiration. Guyton Medical Physiology 11th edition p.515

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33
Q 
The phase that contributes the most to gastric secretion: 
A. cephalic 
B. gastric 
C. esophageal 
D. intestina
A

B
There is no esophageal phase in gastric secretion. Cephalic phase contributes 20%, while the gastric phase is responsible for 70% of total gastric secretion. Guyton Medical Physiology 11th edition p.798

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34
Q 
Primary bile acids are combined with what to form conjugated bile acids? 
A. glutamate 
B. glutamine 
C. glycine 
D. threonine
A

C

Bile acids are conjugated with glycine and taurine. Guyton Medical Physiology 11th edition p.804

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35
Q 
The most potent stimulus for causing gallbladder contractions is: 
A. cholecystokinin 
B. secretin 
C. gastrin 
D. acetylcholine 
E. histamine
A

A

Guyton Medical Physiology 11th edition p.803

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36
Q

Source/s of flatus:
A. swallowed air
B. as a result of bacterial action in gut
C. diffusion from the blood into the GIT
D. A & B
E. all of the above

A

E

Guyton Medical Physiology 11th edition p.825

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37
Q 
The most numerous cells of the islets of langerhans? 
A. alpha cells 
B. beta cells 
C. gamma cells 
D. pp cell
A

B

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38
Q 
The following is/are factor/s that increase insulin secretion: 
A. leptin 
B. fasting 
C. somatostatin 
D. obesity 
E. alpha-adrenergic activity
A

D

Guyton Medical Physiology 11th edition p.968

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39
Q 
True of the prostate gland: 
A. secretes fructose 
B. contributes the bulk of the semen 
C. secretes a slightly alkaline fluid 
D. secretion is mucoid
A

C
The seminal vesicle secretes fructose, and contributes the bulk of the semen. Prostate gland secretion is thin and milky.

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40
Q

The only really effective mechanism to prevent body heat control breakdown in severely cold environments is:
A. panting
B. neuronal effector mechanisms
C. behavioral control of body temperature
D. sweating
E. Piloerection

A

C

Guyton Medical Physiology 11th edition p.895

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41
Q 
At resting membrane potential, the sodium channel must have this configuration: 
A. m gate open and h gate closed 
B. m gate open and h gate open 
C. m gate closed and h gate open 
D. m gate closed and h gate closed
A

C
The m gate is also known as the activation gate, and the h gate is the inactivation gate. In the resting state, the activation (m) gate is closed, and the inactivation gate (h) is open.

42
Q

Binding of epinephrine to a beta adrenergic receptor leads to generation of cAMP from ATP in the presence of adenylyl cyclase. One of the following statements is correct:
A. Epinephrine is the first messenger but is not considered as a ligand
B. ATP is the effector protein
C. Adenylyl cyclase is an enzyme, hence, can?t be considered as an effector protein
D. cAMP serves as a chemical relay from the plasma membrane to the cell?s biochemical machinery

A

D
Epinephrine is both a first messenger and a ligand. ATP is not the effector protein, but the substrate from which cAMP is produced. Adenylyl cyclase is considered an effector protein.

43
Q

A 64 year old male was diagnosed to have heart failure. To increase the heart?s force of contraction, you should give a medication that would:
A. Inhibit the sodium ATPase pump and thereby inhibiting the sodium-calcium pump
B. Lower ECF calcium
C. Inhibit both dihydropiridine and ryanodine receptors
D. Stimulate the active calcium pump

A

A
Inhibition of the Na-K ATPase increases intracellular Na, thereby decreasing the action of the Na-Ca exchange which serves to pump Ca out in exchange for Na. This results in increased intracellular Ca, thereby increasing contractility. This is the mechanism of action of cardiac glycosides given for heart failure.

44
Q 
In smooth muscle contraction, calcium initially binds with: 
A. Troponin C 
B. Ryanodine receptor 
C. Calmodulin 
D. Dihydropiridine receptor
A

C

45
Q

Drugs that increase acetylcholine transmission, such as antiacetylcholinesterases, promote sympathetic as well as parasympathetic responses because:
A. Ach receptors are located in all effector organs that receive autonomic innervation
B. Ach is the transmitter at all sympathetic and parasympathetic postganglionic synapses
C. Ach is the transmitter at all autonomic ganglionic synapses
D. Ach is the sole neurotransmitter in the peripheral nervous system

A

C

46
Q

After appendectomy, a patient was unable to void. To relieve his urinary retention, the surgeon should give:
A. Alpha-1 agonist to contract the urinary sphincter
B. M3 antagonist to relax the bladder wall and contract the urinary sphincter
C. Beta-1 agonist to relax the detrusor muscle
D. M3 agonist to contract the bladder wall and relax the urinary sphincter

A

D

47
Q 
An increase in one of the following parameters will result to a decrease in stroke volume: 
A. Preload 
B. Afterload 
C. Contractility
 D. Venous return
A

B

Increasing all of the other choices would result in increased stroke volume.

48
Q 
Jugular venous pulsation in a patient with tricuspid regurgitation will have an increase in: 
A. a wave 
B. c wave 
C. v wave 
D. x wave
A

C
a wave - corresponds to right atrial contraction c wave - corresponds to right ventricular contraction, causing the closed tricuspid valve to bulge into the right atrium v wave - corresponds to the filling of the right atrium during late systole or early diastole during which the tricuspid valve should still be closed. Tricuspid insufficiency would cause increase in v waves, or in more severe cases, a c-v wave.

49
Q 
During inspiration, this change is expected in right-sided cardiac events: 
A. Increase in preload 
B. Decrease in afterload 
C. Increase in stroke volume 
D. Decrease in contractility
A

A

During inspiration, the fall in intrathoracic pressure causes an increase in venous return or preload.

50
Q

During exercise, one of the following occurs:
A. Sympathetic stimulation will decrease arteriolar constriction
B. Afterload increases
C. Total peripheral resistance decreases
D. Posterior pituitary releases vasopressin

A

C
Sympathetic innervation is the primary regulator of blood flow to the skeletal muscle at rest. However, during exercise, local metabolic mechanisms override sympathetic influence, causing local vasodilation to increase the supply of O2 to the active muscle. The vasodilation in the skeletal muscles contributes to the decrease in total peripheral resistance. Reference: BRS Physiology, 5th ed. p. 95

51
Q 
The binding of oxygen with hemoglobin tends to displace carbon dioxide in the lungs. This is known as the: 
A. Dalton?s law 
B. Bohr effect 
C. Haldane effect 
D. Charles law
A

C
Haldane effect refers to the property of hemoglobin wherein deoxyhemoglobin freely takes up and transports CO2, whereas oxygenated hemoglobin has reduced affinity for CO2. The Bohr effect, on the other hand, states that an increase in blood CO2, which in turn decreases blood pH, promotes unloading of oxygen or decreased affinity of oxygen for hemoglobin.

52
Q 
A diuretic administered to a patient is an aldosterone antagonist that blocks the activity of Na channels found in which cells of the distal tubule and cortical collecting tubule? 
A. Intercalated 
B. Principal 
C. Mesangial 
D. Juxtaglomerular
A

B
The distal tubule has 2 types of cell: the principal and the intercalated cell. The principal cell is responsible for reabsorbing Na and secreting K, and is the site of action of the hormone aldosterone. The intercalated cell functions in acidbase homeostasis and has a H-K ATPase

53
Q

A 65 year old hypertensive patient was noted to have dyspnea, crackles on both lung fields and bipedal edema. The edema is due to:
A. Decreased interstitial colloid oncotic pressure
B. Increased capillary hydrostatic pressure
C. Increased capillary colloid oncotic pressure
D. Unchanged intersitial hydrostatic pressure

A

B

54
Q 
The kidneys regulate acid-base balance by each of the following mechanisms except: 
A. Reabsorbs filtered HCO3 
B. Active reabsorption of H+ 
C. Excreting titratable acid 
D. Acidifying the urine via H+ secretion
A

B
The kidneys do not reabsorb H+ in cases of alkalosis, rather, they increase the excretion of HCO3 by decreasing its reabsorption along the nephron. Reference: Berne, Levy. Physiology, 5th ed. p. 713

55
Q

The rate of aldosterone secretion would decrease in response to a:
A. Fall in renin secretion by the kidney
B. Decrease in tubule fluid sodium concentration at the macula densa
C. Fall in blood pressure
D. Rise in serum potassium

A

A

56
Q 
A 50 year old male underwent craniotomy. At the recovery room, he was noted to have voluminous urine. You assume that he has a deficiency in: 
A. Oxytocin 
B. ACTH 
C. TSH 
D. ADH
A

D

57
Q

The most important factor in influencing the closure of the ductus arteriosus is:
A. Decrease in adenosine levels
B. Increase in O2 tension
C. Increase in plasma catecholamine levels
D. Decrease in prostaglandin levels

A

B

Reference: Berne, Levy. Physiology, 5th ed. p. 431

58
Q 
An athlete?s muscle is composed predominantly of type 1 motor fibers. In which event will he most likely be a winner? 
A. 100 meter race 
B. Weight lifting 
C. Boxing 
D. Marathon
A

D
Type I, or slow twitch fibers, have the capacity for oxidative phosphorylation, fatigue more slowly, and are therefore suited for sustained activities and exercises requiring endurance.

59
Q 
The major urinary buffer excreted during metabolic acidosis is: 
A. Phosphate 
B. Ammonia 
C. Bicarbonate 
D. Protein
A

B

60
Q

True of the third heart sound (S3):
A. Appreciated during early diastole
B. Corresponds to the dicrotic notch of the arterial waveform
C. Due to the closure of the mitral valve
D. Coincides with the P wave of the ECG

A

A

Rapid flow of blood from the atria to the ventricles during early diastole causes the third heart sound.

61
Q

Which of the following is TRUE regarding cerebrospinal fluid (CSF)?
A. CSF is produced at a rate of 21 mL/hr by the choroid plexuses
B. CSF has a lower concentration of potassium, glucose and protein compared to blood
C. CSF is reabsorbed by the arachnoid granulations into to the dural sinuses via bulk flow
D. B and C
E. All of the above

A

E
CSF is produced at a rate of 0.35mL/min or 21ml/hr. CSF has a lower concentration of K+, glucose, and protein but a greater concentration of Na+ and Cl? than blood does. Berne 6th pg 62

62
Q

Tetraethylammonium (TEA) is a poison found in the ovaries of certain species of puffer fish. Raw puffer fish is a prized delicacy in Japan and consumption of improperly prepared puffer fish sushi can be fatal. The reason behind this is that:
A. TEA blocks the sodium voltage gated channels inhibiting action potential generation
B. TEA blocks the potassium voltage gated channels inhibiting action potential generation
C. TEA blocks the calcium voltage gated channels inhibiting action potential generation
D. TEA blocks the acetylcholine release preventing conduction through the NMJ
E. None of the above

A

B

Berne 6th pg 71 A - tetradotoxin; C - ?- conotoxin; D - botulinum toxin

63
Q

A 55/M with severe crushing chest pain was rushed to the ER. On PE, patient was tachycardic, tachypneic with coarse crackles heard in all lung fields. ECG was done which showed ST elevation in leads V1-V6. The crackles can be explained by which of the following alteration/s in the Starling forces?
A. Increased capillary hydrostatic pressure
B. Increased plasma oncotic pressure
C. Decreased plasma oncotic pressure
D. Decreased capillary hydrostatic pressure
E. A and C

A

A
In left ventricular failure pulmonary capillary hydrostatic pressure may exceed plasma oncotic pressure. When this occurs, it may cause pulmonary edema Berne 6th pg 351

64
Q

Which of the following limits inspiration?
A. Activation of the Hering-Breuer reflex
B. Stretching of the smooth muscles of the airways
C. Trigerring of the pneumotaxic center which in turn causes stimulation of the apneustic center
D. A and B
E. All of the above

A

D
Hering-Breuer reflex is an inspiratory inhibitory reflex that arises from afferent stretch receptors located in the smooth muscles of the airways. Stretching of the receptors and results in early exhalation by stimulating the neurons associated with the off-switch phase of inspiratory muscle control. Berne 6th pg 470; Stimulation of the pneumotaxic center INHIBITS the apneustic center thereby limiting the time for inspiration

65
Q 
Proopiomelanocortin is cleaved to produce: 
A. MSH 
B. ACTH 
C. ?-endorphin 
D. A and B 
E. All of the above
A

E

ACTH, MSH, ? -Lipotropin and ?- endorphin Berne 6th pg 714

66
Q 
The major inhibitory signal for aldosterone release is: 
A. hyperkalemia 
B. angiotensin II 
C. hypertension 
D. ANP
E. vasopressin
A

D
Major stimuli for aldosterone production are a rise in angiotensin II and a rise in serum [K+]. The major inhibitory signal is ANP. Berne 6th pg 757

67
Q

The following are TRUE regarding cross-bridge cycling EXCEPT?
A. The binding of ATP to the myosin head reduces its affinity to actin
B. Partial hydrolysis of ATP causes the displacement of the myosin head to the positive end of actin
C. The binding of ADP to the myosin head causes an increase in its affinity to actin
D. A and C
E. No exception

A

C

Berne 6th pg 242

68
Q

Testosterone exerts a multitude of effects in the male. These include the following EXCEPT:
A. Increase in muscle mass and increased bone growth
B. Increased red cell production
C. Maintenance of libido and erectile function
D. Increase in VLDL and LDL and decrease in HDL
E. No exception

A

E

All are effects of testosterone Berne 6th pg 764

69
Q 
Which of the following is the strongest agonist for H+ secretion 
A. Gastrin 
B. Histamine 
C. Acetylcholine 
D. Secretin 
E. A and B
A

B
Both gastrin and histamine strongly stimulate secretion of acid by parietal cells Guyton 12th ed 778 but histamine is the strongest agonist of H+ secretion, whereas gastrin and acetylcholine are much weaker agonists Berne 6th pg 509

70
Q

Mucus protects the gastric epithelium from the effects of H+ and pepsins. Which of the following is/are TRUE?
A. Epithelial cells are kept at a pH of nearly neutral through the effects of mucus
B. Due to the alkaline nature of mucus, the gastric epithelium is well protected from acidity even if the secretion of bicarbonate is reduced
C. The mucus layer separates the acidic contents of the gastric lumen from the bicarbonate rich secretions of the surface epithelial cells
D. A and C
E. All of the above

A

D

Protection of the gastric epithelium depends on adequate levels of BOTH mucus and HCO3? Berne 6th pg 511

71
Q

The following are TRUE regarding G-proteins EXCEPT?
A. Activation of the receptor promotes a conformational change in G-protein and exchange of GDP for GTP
B. The beta subunit along with the bound GTP dissociates from the alpha and gamma subnits
C. The subunit associated with GTP goes on to activate various effector proteins including adenylate cyclase, phosphodiesterases and phospholipases
D. RGS proteins facilitate inactivation of signaling by hydrolysis of GTP to GDP and Pi E. No exception

A

B

alpha subunit is the one bound to GTP Berne 6th pg 42-43

72
Q

When light strikes the pigment epithelium:
A. it causes a reduction in cGMP leading to the closure of sodium channels and subsequent hyperpolarization
B. it causes an increase in cAMP leading to opening of sodium channels and subsequent depolarization
C. it causes an increase in DAG and PIP2 leading to release of calcium and subsequent depolarization
D. None of the above

A

A
When light is absorbed, the photoisomerization of rhodopsin activates a G protein called transducin which in turn, activates cGMP phosphodiesterase. This results in the, hydrolysis of cGMP to 5?-GMP, and lowers the cGMP concentration in the rod cytoplasm. The reduction in cGMP leads to closure of the cGMP-gated Na+ channels, hyperpolarization of the photoreceptor membrane, and a reduction in the release of transmitter. Berne 6th pg 128

73
Q

During the cardiac action potential, the plateau is generated by:
A. Influx of calcium into the myocytes
B. Efflux of sodium out of the myocytes
C. Efflux of potassim out of the myocytes
D. Influx of sodium into the myocytes
E. A and C

A

E
Phase 0: sodium influx, depolarization; Phase 1: Early repolarization, potassium efflux; Phase 2: Plateau, calcium influx, continuing potassium efflux; Phase 3: Final repolarization, potassium efflux > potassium influx, decreasing calcium influx; Phase 4: Restoration of ionic concentrations, potassium influx very SLIGHTLY exceed potassium efflux Berne 6th pg 294-299

74
Q 
In the cardiac cycle, the second heart sound is heard during: 
A. Isovolumic relaxation 
B. Isovolumic contraction 
C. Rapid ventricular ejection 
D. Rapid ventricular filling 
E. Atrial contraction
A

A

S1 isovolumic contraction Berne 6th pg 322

75
Q 
During the embryonic period, blood is synthesized by the 
A. Yolk sac 
B. Liver 
C. Bone marrow 
D. Lymph nodes 
E. None of the above
A

A
AGM/Yolk sac - 3rd week - 3rd month AOG; Liver (plus spleen, LN) - 3rd month AOG - birth; Bone marrow - 4th month AOG - postnatal life Topnotch Embryonic period starts from the 3rd week after ovulation and fertilization lasts 8 weeks Williams 23rd pg 79 or 24th pg 128

76
Q 
Each hormone uses a specifc signal transduction system to convey its message into the cell. Which hormone/s use/s BOTH the cAMP and the IP3/DAG pathway for signal transduction? 
A. ACTH 
B. Thyroid hormone 
C. Vasopressin 
D. CRH 
E. A and C
A

C
Vasopressin/ADH V2 cAMP, ADH V1 IP3/DAG; Angiotensin II epithelial cells cAMP, Angiotensin II vascular smooth muscles IP3/DAG; ACTH & CRH cAMP; thyroid hormone binds directly to nuclear receptors to increase transcription of specific genes Guyton 12th ed pg 889-891

77
Q 
When UVB hits the basal layers of the skin, conversion of \_\_\_\_\_\_\_\_\_ into Vitamin D3 occurs.
A. cholesterol 
B. 7-dehydrocholesterol 
C. cholecalciferol 
D. hydroxycholecalciferol 
E. Vitamin D2
A

B
Vitamin D3/cholecalciferol is synthesized via the conversion of 7- dehydrocholesterol by ultraviolet B light (UVB) in the more basal layers of the skin Berne 6th pg 699

78
Q

Which of the following is/are TRUE regarding solute transport in the nephron?
A. Glucose is absorbed in the PCT through SGLT-2
B. Sodium is actively transported in alll parts of the renal tubule
C. Majority of calcium is reabsorbed in the DCT transcellularly
D. All of the above

A

A
Na reabsorption does not occur in the descending thin limb Berne 6th pg 585 Majority of calcium is reabsorbed in the PCT via both transcellular and paracellular pathways pg 630

79
Q 
What allows calcium to be stored at high concentrations inside the sarcoplasmic reticulum? 
A. DHPR 
B. Calsequestrin 
C. RYR 
D. Troponin C 
E. None of the abov
A

B
Calsequestrin is a low-affinity calcium binding protein inside the terminal cisternae. It allows calcium to be stored at high concentration and favors a concentration gradient that facilitates the efflux of calcium from the SR into the myoplasm; DHPR dihydropyridine receptor, voltage sensor; RYR ryanodine receptor, opening causes calcium release from the SR Berne 6th pg 239

80
Q

Which of the following have the capacity to generate slow wave activity in the GI tract?
A. D cells
B. G cells
C. Enterochromaffin-like cells
D. Interstitial cells of Cajal E. Parietal cells

A

D
D cells: somatostatin; G cells: gastrin; ECL cells: histamine; Parietal cells: HCl; ICCs are ?pacemaker? cells that have the capacity to generate the basic electrical rhythm, or slow wave activity Berne 6th pg 511

81
Q 
Which layer of the cornea is responsible for maintaining its deturgescence? 
A. Epithelium 
B. Bowman's layer 
C. Stroma 
D. Descemet's membrane 
E. Endothelium
A

E

Deturgescence refers to a relative state of dehydration, which is needed to maintain the transparency of the cornea.

82
Q 
A patient presented to you with findings of hypotension, muscle weakness, weight loss, hyponatremia and hyperkalemia. On further examination, you noted hyperpigmentation of the skin, which included areas not exposed to the sun. With your diagnosis in mind, this skin finding is most likely due to increased secretion of which of the following substances? 
A. Lipotropin 
B. Melatonin 
C. Cortisol 
D. Aldosterone 
E. None of the above
A

E
Diagnosis: Addison Disease. The skin hyperpigmentation is due to increased production of melanocyte-stimulating hormone (MSH), which share the same precursor molecule as ACTH. Aldosterone is deficient in this disease. Melatonin is secreted by the pineal gland and functions in the maintenance of the biological clock.

83
Q 
Cholesterol absorption occurs in which part of the gastrointestinal tract? 
A. Stomach 
B. Duodenum 
C. Jejunum 
D. Ileum 
E. Both C and D
A

C
Fats and cholesterol are released by bile salts and reabsorbed in the jejunum. Bile salts are then reabsorbed in the ileum. Other substances that are absorbed in the ileum include vitamins A, D, E, K and B12.

84
Q 
Which of the following is not an inspiratory muscle? 
A. External intercostal muscles 
B. Innermost intercostal muscles 
C. Sternocleidomastoid 
D. Serratus posterior inferior 
E. Serratus anterior
A

D

85
Q

A marathon runner has been running for 15 minutes. At this point, which of the following sources of energy is most likely sustaining his activity?
A. Cell phosphocreatine
B. Anaerobic respiration
C. Glycogen
D. Ketone bodies
E. Amino acids being shunted to gluconeogenesis

A

C
First 8-10 seconds: phosphagen energy system. Next 1.3 to 1.6 minutes: glycogen-lactic acid system. Thereafter: aerobic system (initially glycogen stores; fats, ketones and amino acids once glycogen stores are depleted)

86
Q 
Which of the following is the most common cause of female infertility? 
A. Failure to ovulate 
B. Stress 
C. Anorexia nervosa 
D. Prolactinoma 
E. Hyperthyroidism
A

A
SIMILAR TO PREVIOUS BOARD EXAM CONCEPT/PRINCIPLE. The most common cause of female infertility is anovulation, and in which the most common cause is PCOS.

87
Q 
Which of the following anterior pituitary hormones is the most abundant in the body? 
A. Prolactin 
B. Growth hormone 
C. Adrenocorticotropic hormone 
D. Follicle-stimulating hormone 
E. Thyroid-stimulating hormone
A

B

SIMILAR TO PREVIOUS BOARD EXAM CONCEPT/PRINCIPLE.

88
Q 
ST segment elevation in leads II, III and aVF represents myocardial infarction in which wall of the heart? 
A. Inferior wall 
B. Anterior wall 
C. Septal wall 
D. Anteroseptal wall 
E. Lateral wall
A

A

II, III, aVF –> inferior wall. V1, V2 –> septal wall. V3, V4 –> anterior wall. V5, V6 –> lateral wall.

89
Q 
Which of the following substances is known as the most potent naturally occurring vasocontrictor in the body? 
A. Endothelin 
B. Bradykinin 
C. Vasopressin 
D. Serotonin 
E. Prostaglandin F
A

C

90
Q 
In which of the following organs is blood flow mainly regulated by the sympathetic nervous system? 
A. Skin 
B. Brain 
C. Heart 
D. Exercising muscles 
E. Kidneys
A

A
Blood flow in the skin and resting muscles is mainly controlled by the sympathetic nervous system. In contrast, blood flow in the brain, heart, kidneys and exercising muscles is mainly under autoregulation and local control.

91
Q

A 19-year old male was caught in a gang war and was hit in the epigastric area with strong direct punch. He suddenly developed hypotension, bradycardia and weak pulses. Which of the following best explains these findings?
A. Gastric perforation and pneumoperitoneum
B. Rupture of the abdominal aorta
C. Hepatic contusion and subcapsular hematoma
D. Vaso-vagal reflex stimulation
E. Development of an intraperitoneal hematoma

A

D

SIMILAR TO PREVIOUS BOARD EXAM CONCEPT/PRINCIPLE.

92
Q 
One mechanism by which PTH increases the body's blood calcium level is by stimulating the kidney to increase calcium reabsorption. At which portion of the renal tubular system does PTH act? 
A. Proximal convoluted tubule 
B. Ascending limb of the loop of Henle 
C. Early distal tubule 
D. Late distal tubule 
E. Collecting duct
A

C
Calcium reabsorption in the loop of Henle occurs via the paracellular route. Calcium reabsorption in the early distal tubule occurs via luminal calcium channels and basolateral Na/Ca exchangers. PTH regulates calcium reabsorption through these channels.

93
Q 
The intrinsic and extrinsic pathways of the coagulation cascade converge at which of the following clotting factors? 
A. Labile factor 
B. Stable factor 
C. Stuart factor 
D. Tissue factor E. Hageman factor
A

C
Common pathway: factor X (Stuart factor) –> factor V (Labile factor) –> factor II (prothrombin) –> factor XIII (fibrin-stabilizing factor). *Mnemonic: 10 + 5 - 2 = 13. Factor VII (Stable factor) and factor III (tissue factor) are from the extrinsic pathway. Factor XII (Hageman factor) is from the intrinsic pathway

94
Q 
Which of the following parameters is increased in COPD? 
A. Forced vital capacity 
B. Forced expiratory volume 
C. Functional residual capacity 
D. Expiratory reserve volume 
E. None of the above
A

C

The rest of the parameters mentioned are decreased in COPD.

95
Q 
In type III hypersensitivity reactions, deposition of antibody-antigen complexes in basement membranes can elicit inflammation through which of the following mechanisms? 
A. Alternative complement pathway 
B. Classical complement pathway 
C. Cytotoxic T cell activation 
D. Induced cell apoptosis 
E. Eosinophilic degranulation
A

B

SIMILAR TO PREVIOUS BOARD EXAM CONCEPT/PRINCIPLE

96
Q

Performing a carotid sinus massage would produce all of the following effects except:
A. Decreased heart rate
B. Decreased aortic blood pressure
C. Increased activity and discharge from carotid baroreceptors
D. Activation of the reninangiotensin-aldosterone system
E. None of the above

A

D

97
Q 
Which of the following is a known complication of rapid correction of hypernatremia? 
A. Cerebral edema 
B. Central pontine myelinolysis 
C. Hypotension 
D. Rhabdomyolysis 
E. All of the above
A

A
Overcorrection of hypernatremia causes cerebral edema. Overcorrection of hyponatremia causes central pontine myelinolysis

98
Q

A 60-year old stage IV breast cancer patient is in her 18th hospital day when she was referred for dyspnea and tachypnea. Chest radiograph was requested and you noted a new-onset focal area of oligemia in the right lower lung field. If ABG were be performed on her, what would be your expected finding?
A. Respiratory acidosis
B. Respiratory alkalosis
C. Metabolic acidosis with high anion gap
D. Metabolic acidosis with normal anion gap
E. Metabolic alkalosis

A

B
Diagnosis: pulmonary embolism. Chest radiograph describes the Westermark sign. Respiratory alkalosis secondary to hyperventilation (tachypnea) would be expected.

99
Q

Which of the following statements is least accurate in describing the events occurring during muscle contraction?
A. The H-band and I-zone in the sarcomere shorten during contraction.
B. Calcium is the main ion that facilitates actinmyosin cross-bridge cycling.
C. The hydrolysis of an ATP molecule attached to the myosin head drives the “power stroke”.
D. Sodium influx and potassium efflux both contribute to the depolarization of the motor endplate following stimulation by acetylcholine.
E. All of the above statements are true

A

C

The power stroke is driven by the released of hydrolyzed ATP (now in the form of ADP and Pi) from the myosin head.

100
Q

The transport of calcium ions back to the sarcoplasmic reticulum during muscle relaxation is achieved through which of the following mechanisms?
A. Simple diffusion
B. Facilitated diffusion
C. Primary active transport
D. Secondary active transport via symport
E. Secondary active transport via antiport

A

C

This process is achieved through CAATPase pumps in the sarcoplasmic reticulum (known as SERCA).

Physiology (6 decks)

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