Physiology 301-400 Flashcards
1
Q
Which of the following coincides with the second heart sound?
A. Closure of mitral valve and tricuspid valves
B. Closure of the aortic and pulmonic valves
C. Flow of blood during rapid ventricular filling
D. Late diastole or atrial systole (slow ventricular filling)
E. None of the above
A
B
IM platinum p42
2
Q
Which of the following correctly depicts the formula for blood pressure?
A. Blood pressure= cardiac output x heart rate
B. Blood pressure= heart rate X cardiac output
C. Blood pressure= stroke volume X total peripheral resistance X heart rate
D. Blood pressure= cardiac output x stroke volume
E. Blood pressure= total peripheral resistance x stroke volume
A
C
BP=CO x TPR; CO= HR x SV
3
Q
Continued production of this estrogen depends on the living fetus, hence is used as a marker of fetal well-being: A. Estrone B. Estradiol C. Estriol D. All of the above E. None of the above
A
C
4
Q
Which of the following statements regarding depolarization is true?
A. Depolarization is making the membrane potential less negative.
B. Depolarization is making the mambrane potential more negative.
C. Depolarization is the membrane potential in which occurrence of action potential is inevitable.
D. Depolarization is the period in which a new action potential can be elicited.
E. Depolarization is the period in which a new action potential can not be elicited.
A
A
B. Depolarization is making the mambrane potential more negative. - Hyperpolarization C. Depolarization is the membrane potential in which occurrence of action potential is inevitable. - Threshold D. Depolarization is the period in which a new action potential can be elicited. - no answer E. Depolarization is the period in which a new action potential can not be elicited. -Refractory period
5
Q
Which of the following nerve fiber type conducts action potential the fastest? A. Type A? B. Type A? C. Type B D. Type C E. None of the above
A
A
Type C- slowest, non-myelinated
6
Q
This lobe of the brain is responsible for hearing, vestibular processing, recognition of faces and storage of memory? A. Frontal lobe B. Parietal lobe C. Temporal lobe D. Occipital lobe E. None of the above
A
C
Frontal- motor, personality, calculation Parietal-Somatosensory OccipitalVision
7
Q
Lesions in this part of the brain causes loss of preexisting memories or retrograde amnesia: A. Thalamus B. Hippocampus C. Amygdala D. Hypothalamus E. None of the above
A
A
Thalamic lesions-cause retrograde amnesia Hippocampal lesions- cause anterograde amnesia
8
Q
These brain waves predominate in a person who is doing his thesis at 10am in the morning: A. Alpha waves B. Beta waves C. Theta waves D. Delta waves E. None of the above
A
B
A. Alpha waves- awake, eyes closed; relaxing person B. Beta waves- awake, eyes open; busy and alert C. Theta waves-brain disorders and degenerative brain states D. Delta waves-deep sleep and organic brain disease and infants
9
Q
This tactile receptor is an onion-like structure in the skin and deep fascia that detects highfrequency vibration: A. Pacinian corpuscle B. Ruffini's end organs C. Merkel's Disc D. Meissner's corpuscle E. Free nerve endings
A
A
B. Ruffini’s end organs- detects pressure and joint rotation C. Merkel’s Disc- for localizing touch sensation and to determine texture D. Meissner’s corpuscle-found in nonhairy skin as finger tips; for lowfrequency vibration E. Free nerve endings-found in the skin; touch and pressure
10
Q
These blood vessels are also known as capacitance vessels because of its function as reservoir of blood: A. Arterioles B. Arteries C. Veins D. Capilaries E. None of the above
A
C
Veins are easily distensible. It holds more than 60% of blood at any time.
11
Q
What does Tall T waves in contiguous leads in an ECG tracing imply? A. Hyperkalemia B. Hypercalcemia C. Hypokalemia D. Hypocalcemia E. None of the above
A
A
B. Hypercalcemia- shortened QT interval C. Hypokalemia- flat T waves D. Hypocalcemia- Prolonged QT interval
12
Q
The following are part of the Cushing reflex in response to increased intracranial pressure, except: A. Irregular respiration B. Bradycardia C. Hypotension D. All of the above E. None of the above
A
C
Cushing reflex: HPN, Bradycardia, Irregular respiration
13
Q
The following vasocative mediators are vasodilators, except: A. Serotonin B. Prostacyclin C. Nitric oxide D. Histamine E. None of the above
A
A
Serotonin- is released as a result of blood vessel damage; it causes arteriolar vasoconstriction; implicated in migraineq
14
Q
The following are true of slow-twitch or red muscles, except:
A. Smaller in size
B. Glycolytic in metabolic profile
C. Slower Calcium reuptake by sarcoplasmic reticulum
D. Has more numerous mitochondria
E. For endurance activities
A
B
fast-twitch/ white muscle=glycolytic; slow-twitch/red muscle=oxidative
15
Q
What is the function of Troponin I? A. Attaches troponin complex to tropomyosin B. Inhibits actin-myosin binding C. Inhibits calcium binding protein D. All of the above E. None of the above
A
B
SIMILAR TO PREVIOUS BOARD EXAM CONCEPT/PRINCIPLE: Troponin Tattaches troponin complex to tropomyosin; Troponin I-inhibits actinmyosin binding; Troponin C- calcium binding protein
16
Q
One of the manifestations of Decompression sickness caused by sudden formation of nitrogen bubbles that blocks blood vessels from rapid ascent is pain in the joints and muscles. What is its other name? A. Chokes B. Turns C. Bends D. Caisson's Disease E. All of the above
A
C
Chokes-dyspnea; Caisson’s-Chronic decompression sickness
17
Q
The following statements are true regarding the kidneys, except:
A. Left kidney is lower than the right kidney.
B. Glomerular capillaries are the only capillaries that lead to artetioles.
C. Kidneys produce calcitriol, renin and erythropoietin.
D. Peritubular capillaries participate in countercurrent exchange.
E. None of the above
A
A
Right is lower (because of the liver)
18
Q
This refers to the intrinsic ability of the tubules to increase their reabsorption rate in response to increased tubular load: A. Glomerulotubular balance B. Tubuloglomerular feedback C. Gradient-time transport D. Renal blood flow E. None of the above
A
A
Glomerulotubular balance- percentage of solute reabsorbed is held constant Tubuloglomerular feedback-constant sodium load delivered to distal tubule
19
Q
The following promotes entry of potassium into cells, except: A. Insulin B. Aldosterone C. Beta agonists D. Alkalosis E. None of the above
A
E
Factors that shift potassium out of cells: insulin deficiency, addison’s, Bblockers, acidosis, cell lysis, strenous exercise, increased ECF osmolality
20
Q
What is the last nucleated stage of RBC? A. Proerythroblast B. Basophilic eryhtroblast C. Polychromatophilic erythroblast D. Orthochromatic erythroblast E. Reticulocyte
A
D
Orthochromatic erythroblast-last nucleated stage
21
Q
An 87-year-old nursing home resident with dementia, Alzheimer's type, is admitted to the hospital because of progressive lethargy and decreased appetite for 3 days. She had a flu-like illness followed by a deep cough 1 week ago. Over the past 10 months, she has been hospitalized once for bacterial pneumonia. She is responsive only to painful stimuli. Her temperature is 38.6 C (101.5 F), blood pressure is 110/60 mm Hg, pulse is 123/min and regular, and respirations are 28/min. Examination shows dry mucous membranes. There is no adenopathy. Crackles are heard in the right lung base. An x-ray film of the chest shows an infiltrate at the right lung base. The remainder of the examination shows no abnormalities. Which of the following is the most likely predisposing factor for this patient's pneumonia? A ) Decreased airway elasticity B ) Decreased baroreflex C ) Decreased gag reflex D ) Decreased thyroid function
A
C
22
Q
A 72-year-old man comes to the physician because of a 7-month history of leg weakness and dry eyes and mouth. He also has had a 10.4-kg (23-lb) weight loss over the past 4 months despite no change in appetite. He has smoked one and a half packs of cigarettes daily for 50 years. He drinks 4 oz of alcohol daily. He has peptic ulcer disease and emphysema. Medications include cimetidine, theophylline, and lowdose prednisone. Examination shows mild ptosis. He has a barrelshaped chest. Breath sounds are distant. There is moderate weakness of the proximal muscles of the lower extremities. Reflexes are absent. He has difficulty rising from a chair. Sensory examination shows no abnormalities. An x-ray film shows a hyperinflated chest and a 3 x 4-cm mass in the right hilum. His neurologic findings are most likely due to a lesion involving which of the following? A) Choline acetyltransferase B) Acetylcholinesterase C) Postynaptic neuromuscular junction D) Presynaptic neuromuscular junction
A
D
23
Q
A 37-year-old woman comes to the physician because of progressive shortness of breath over the past 5 years; she now has fatigue and shortness of breath with mild exertion. She has a history of mitral stenosis secondary to rheumatic fever at the age of 15 years. She was asymptomatic until 5 years ago when she developed severe shortness of breath during pregnancy. She was treated with diuretics, low-sodium diet, and bed rest, and she was able to deliver the baby at term. Her only medication is hydrochlorothiazide. Her temperature is 37 C (98.6 F), blood pressure is 110/80 mm Hg, pulse is 100/min and regular, and respirations are 26/min. Cardiac examination shows an obvious opening snap in S2. A grade 3/6, late diastolic murmur is heard at the apex. A right ventricular lift is palpated along the left sternal border. Which of the following is most likely increased in this patient?
A) Blood flow to the lower lung fields
B) Pulmonary artery pressure
C) Left-to-right shunt of blood
D) Left ventricular enddiastolic pressure
A
B
24
Q
A 52-year-old scuba diver has a malfunctioning oxygen tank at 80 feet below sea level. Panicking about this occurrence, she made every effort to immediately resurface. Upon reaching the surface, she had severe difficulty of breathing. Which among the following explains why this happened to her?
A) Nitrogen microbubbles plugging the pulmonary capillaries
B) Swallowing excess amounts of sea water
C) Nitrogen narcosis in the central nervous system
D) Free radical damage to the pulmonary vasculature
A
A
25
```
A newborn infant is born with 5-alpha reductase deficiency. Examination of his blood would reveal decreased levels of which among the following compounds?
A) Androstenedione
B) Dihydrotestosterone
C) Estradiol
D) Pregnenolone
```
B
26
```
Which among the following physiologic principles pertains to iodine-induced hyperthyroidism, typically presenting in a patient with endemic goiter who relocates to an iodine-abundant geographical area?
A) Wolff-Chaikoff effect
B) Frank-Starling mechanism
C) Jod-Basedow phenomenon
D) Bainbridge reflex
```
C
27
```
Aldosterone synthase is only present in one portion of the adrenal gland. This explains why this is the only portion capable of producing aldosterone, a mineralocorticoid hormone that is essential for life. Which among the following is the site of aldosterone production?
A) Zona glomerulosa
B) Zona fasciculate
C) Zona reticularis
D) Adrenal cortex
```
A
28
```
Without a countercurrent exchanger, the solutes pumped into the renal medulla by the countercurrent multiplier system would be rapidly dissipated. Which among the following structures is responsible for this phenomenon in human nephrons?
A) Loop of Henle
B) Proximal convoluted tubule
C) Vasa recta
D) Distal convoluted tubule
```
C
29
```
Which of the following refers to the intrinsic ability of tubules to increase their reabsorption rate in response to increased tubular load?
A) Tubuloglomerular Feedback
B) Glomerulotubular Balance
C) Countercurrent Multiplication
D) Local Autoregulation
```
B
30
A 45-year-old man who underwent bowel surgery developed pernicious anemia as a consequence. Which among the following will most likely be observed in this patient?
A) Low dietary intake of ferrous sulfate
B) Hypertrophy of gastric mucosa
C) Excess levels of pyridoxine in the blood
D) Decreased production of hydrochloric acid by gastric parietal cells
D
31
A 34-year-old man is suffering from gastrointestinal complications. On examination of his gastrointestinal fluids, gastric fluids were noted to have increased [H+], bile had decreased [HCO3] and pancreatic fluids had decreased [HCO3]. Which among the following GIT hormones is most likely deficient in this patient?
A) Cholecystokinin
B) Gastrin
C) Glucose-dependent insulinotropic peptide (GIP)
D) Secretin
D
32
```
Respiratory distress developed in a neonate born at 30 weeks age of gestation. On chest radiograph, areas of atelectasis were seen. Which among the following represents the dominant component of the deficient pulmonary surfactant in this patient?
A) Phosphatidylcholine
B) Phosphatidylserine
C) Phosphatidylinositol
D) Phosphatidylpalmitate
```
A
33
```
The affinity of oxygen for hemoglobin increases in which of the following situations?
A) Hypothermia
B) Metabolic acidosis
C) Exercise
D) Chronic hypoxemia
```
A
34
Following a sympathectomy, a 66- year-old man experiences orthostatic hypotension. Which among the following may explain this occurrence?
A) An exaggerated response of the reninangiotensin-aldosterone system
B) A suppressed response of the renin-angiotensinaldosterone system
C) A suppressed response of the baroreceptor mechanism
D) An exaggerated response of the baroreceptor mechanism
C
35
```
A 65-year-old female who had a traumatic brain injury seems to be able to understand the written and spoken word but cannot create the correct sounds to be able to speak a word that is recognizable. She most likely has damage to which area of the brain?
A) Wernicke’s area
B) Broca’s area
C) Angular gyrus
D) Arcuate fasciculus
```
A
36
The myelin sheath of nerves is produced by supportive cells like oligodendrocytes in the central nervous system and Schwann cells in the peripheral nervous system. The following are consequences of myelination of nerve fibers EXCEPT?
A) Decrease in nonselective diffusion of ions across the axonal membrane
B) Increase in energy required to maintain ion gradients across the membrane
C) Increase in the velocity of nerve impulses along
the axon
D) Generation of action potentials only at nodes of Ranvier
B
37
```
Which among the following transport mechanisms is limited by a saturable transport maxima?
A) Facilitated diffusion
B) Simple diffusion
C) Osmosis
D) Filtration
```
A
38
```
Skeletal muscle contraction will cease and relaxation will commence when calcium ions are pumped back into which of the following structures?
A) Endoplasmic reticulum
B) Transverse tubules
C) Neuromuscular junction
D) Sarcoplasmic reticulum
```
D
39
```
A 22-year-old man is brought to the emergency room after a traffic accident causing a traumatic brain injury. Within several hours he begins eating objects such as paper, is unable to maintain attention, and displays increased sexual activity. A diagnostic MRI reveals bilateral amygdala lesions. Which among the following best explains this patient's condition?
A) Parkinson's disease
B) Kluver-Bucy syndrome
C) Gerstmann's syndrome
D) Brown-Sequard syndrome
```
B
40
Why is atrial repolarization not visible in a normal ECG tracing?
A) Because it is buried in the concurrent QRS complex
B) Because it is isoelectric and hence cannot be seen
C) Because it is of too low voltage to be detected by the ECG
D) Because it occurs together with ventricular repolarization
A
41
A 26 year primigravid patient is about to deliver her baby. During your labor watch you notice that the uterine contractions occur at >20 minute interval. You decided to do nipple massage to stimulate the release of a hormone which would improve uterine contrations. Which of the following stuctures/areas in the hypothalamus releases this hormone?
A. Gigantocellular Cells in Paraventricular Nuclei
B. Magnocellular Cells in Paraventricular Nuclei
C. Magnocellular cells in the Supraoptic Nuclei
D. Gigantocellular cells in the supraoptic nuclei
E. None of the Above
B
| Oxytocin is produced in the magnocellular cells of the paraventricular nuclei
42
Which of the following CORRECTLY describes the function of vasopressin in the following organ systems?
A. Kidney: increases the water permeability in the proximal tubule and collecting duct which allows reabsorption and excretion of a more concentrated urine
B. Kidney: decreases the permeability of the inner medullary portion of the collecting duct to urea
C. Central Nervous System: implicated in motor movements
D. Cardiovascular: increases peripheral vascular resistence therefore increasing blood pressure
E. All of the above
D
| A - distal tubule B- increases the permeability to urea
43
```
A young soccer player had an accidental collision with his opponent during the game. After the collision, the player suddenly dropped down dead due to a fatal arrythmia. This condition is triggered by a a blunt trauma to the heart during the susceptible phase of the heart. This MOST COMMONLY occurs if the blunt trauma occurs:
A. before the peak of the p wave
B. before the peak of the r wave
C. before the start of the qrs complex
D. before the peak of the t wave
E. before the peak of the u wave
```
D
| commotio cordis - v fib blunt trauma just before the peak of t wave
44
```
An average individual has a respiratory rate of 16 breaths per minute. His measured tidat volume is 500ml. What is the alveolar ventilation of this patient?
A. 7L
B. 6.5L
C. 6L
D. 5.5L
E. 5L
```
D
| Va = RR x (VT-VD)
45
```
Hypoventilation causes the oxy-hemoglobin curve to shift to the:
A. Right
B. Left
C. Upward
D. Downward
E. Change
```
A
46
```
Which of the following decreases Cobalamin (vitamin b12) in the body?
A. Vitamin A
B. Vitamin D
C. Vitamin C
D. Vitamin E
E. Vitamin K
```
C
| Ascorbic acid decreases the absorption of cobalamin
47
```
Which of the following describes the effect on hyperkalemia on a patient's electrocardiogram?
A. Reduction of size of the P wave
B. Development of peaked T waves
C. Widening of the QRS complex
D. Evolution to a sinusoidal shape
E. All of the above
```
E
| All of the above are ECG findings in hyperkalemia
48
A patient with congestive heart failure with EF
D
| Spironolactone - inhibits Na absorption and K excretion by inhibiting aldosterone
49
A 23 year old male is suffering from a large tumor located at the cauda equina. Which of the following describes the effect of a compressive tumor to the bladder?
A. The bladder becomes initially flaccid and distended
B. The bladder may become active and expels urine
C. The bladder may be shrunked
D. The bladder may hypertrophy
E. All of the above
E
When the afferent and efferent nerves are both destroyed, as they may be by tumors of the cauda equina or filum terminale, the bladder is flaccid and distended for a while. Gradually, however, the muscle of the "decentralized bladder" becomes active, with many contraction waves that expel dribbles of urine out of the urethra. The bladder becomes shrunken and the bladder wall hypertrophied.
50
```
An individual was brought into the emergency department following a motorbike collision. He was conscious and reports no loss of consciousness after the incident. There is no physical evidence of any head trauma. However, upon examination of this individual, the following sensory deficits are noted: loss of fine touch and vibration sense in both the left arm and leg including the hand and foot, loss of pain and temperature sense in the right arm and leg including the hand and foot. In the description above, one can RULE OUT a lesion in which of the following areas of the nervous system?
A. Midbrain
B. Medulla
C. Brainstem
D. Cortex
E. Peripheral nerves
```
D
51
A 24 year old female presents with inappropriate eating and she puts everything in her mouth. Patient also has difficulty in recognizing individuals. You are suspecting a bilateral lesion in one of the structures of the limbic system. The structure involved in this case is also important in?
A. Comprehension of auditory and visual function
B. Transfer of information between 2 hemisphere
C. Consolidation of memory
D. Recognizing severe pain and fear
E. None of the above
D
52
```
The human brain has the ability to determine which stimulus is important and should always be recognized and which stimulus can be ignored. A perfect example is that after wearing your clothes for quite sometime, your body do recognize the "feel" of your clothes to your skin. This process is best explained by which of the following concepts?
A. Habituation
B. Sensitization
C. Classical conditioning
D. Operant conditioning
E. Learning
```
A
53
```
Circadian rhythms are highly influenced by the external environment. It is mainly regulated by a hormone which is stimulated by darkness. From which of the following amino acids is this hormone synthesized from?
A. Tyrosine
B. Serotonin
C. Melanin
D. Glycine
E. Tryptophan
```
E
| Tryptophan
54
```
The stucture of the limbic system which receives neuronal signals from all portions of the cortices is involved in which of the following functions?
A. Tranquility
B. Voluntary Muscle movement
C. Severe Pain
D. Rewards Center
E. None of the above
```
C
55
```
Fast pain, usually described as sharp and localized, is carried by which of the following?
A. small, unmyelinated C fibers
B. small, myelinated Adelta fibers
C. small, unmyelinated C fibers
D. large, myelinated Abeta fibers
E. large, unmyelinated C fibers
```
B
56
```
43 year old patient who presents with malar rash, anemia, chronic kidney disease and positive ANA presented is being treated with prednisone. Which of the following is/are known potential problem/s of chronic prednisone/steroid use?
A. Hypertension
B. Hyperkalemia
C. Thickening of the skin
D. Bone formation
E. Hypercalcemia
```
A
| Cushing's syndrome
57
```
A 73 year old diabetic came in at the E.R. For decrease in sensorium. Initial CBG revealed "Hi." The E.R. Physician suspected a possible diabetic emergency in this case. On History, it was noted that the patient had severe diarrhea for the past few days. Which of the following Blood Gas is consistent with the patient's condition?
A. pH 7.32 pCO2 18 HCO3 12
B. pH 7.32 pCO2 80 HCO3 32
C. pH 7.36 pCO2 35 HCO3 20
D. pH 7.47 pCO2 25 HCO3 28
E. pH 7.40 pCO2 40 HCO3 22
```
C
| HHS
58
Growth hormone will DECREASE which of the following:
A. Uptake of glucose into the cell
B. Mobilization of fat from adipose tissue
C. Amino acid transport into the cell
D. Transcription of DNA to RNA
E. All of the above
A
59
Which of the following is a physiologic action of progesterone:
A. Promote proliferative changes in the endometrium
B. Increased frequency and intensity of uterine contraction
C. Stimulate the development of lobules and alveoli in the breast
D. Increased osteoblastic activity
E. None of the above
C
60
A 36 year old male was diagnosed with AML. He is admitted for blood transfusion due to low hemoglobin. The NOD called your attention because the patient is suffering from fever. Transfusion was immediately stopped. Upon attending to the patient and looking at the chart, you noted that the patient has a blood type "O neg". You then checked the blood transfused and you noted that it was type "O neg" as well. Which among the following best explains the incident?
A. Preformed antibodies against donor RBCs
B. undetected allo-Abs against minor antigens
C. Abs againts donor WBCs and cytokines released in blood product
D. IgA deficiency with IgA abs
E. Rh incompatibility
C
61
```
When molecules or ions move uphill against a concentration gradient, the process is called
A. simple diffusion
B. facilitated diffusion
C. osmosis
D. active transport
```
D
| Active transport is the process of moving substances uphill against concentration gradient
62
Parkinson’s disease results from loss of
A. cell bodies of GABAsecreting neurons in the caudate nucleus
B. Ach-secreting neurons in the many parts of the brain
C. dopamine due to destruction of substantia nigra
D. serotonin due to destruction of the brainstem
C
| Dopamine deficiency in the basal ganglia characterize Parkinsons disease
63
```
Causes of true visceral pain include:
A. Ischemia
B. Spasm of hollow viscus
C. Chemical stimuli
D. All of the above
```
D
| All of the above cause visceral pain
64
```
Mechanism involved when heat is lost thru electromagnetic rays is by:
A. convection
B. radiation
C. evaporation
D. conduction
```
B
| Radiation is the mechanism of loss of heat through noncontiguous surfaces
65
```
The attraction of the white blood cells to the site of injury is called
A. diapedesis
B. margination
C. chemotaxis
D. phagocytosis
```
C
66
```
The process of gas exchange in the lungs is by
A. simple diffusion
B. facilitated diffusion
C. endocytosis
D. filtration
```
A
Answer: Simple diffusion allows the freely permeable oxygen gas to penetrate through the alveolar wall from high to low concentration gradient.
67
```
The following have direct effects on the respiratory center in the medulla
A. Carbon Dioxide
B. Oxygen
C. Hydrogen ions
D. A and C
```
D
| Both CO2 and H+ exert their effects in the Respiratory center
68
```
The heart vector extends mainly in the same direction as the axis of Lead
A. I
B. II
C. III
D. AVL
```
B
| Lead II, based on Einthoven’s triangle
69
True for Diabetics :
A. have decreased plasma amino acid concentrations
B. have low amounts of acetyl-coA
C. increases the use of free fatty acids in most tissues
D. increases protein synthesis
C
| Answer: In DM2, FFA is increased in both plasma levels and its usage. A, B, and D are not effects of insulin deficiency
70
Severe vasoconstriction of efferent arterioles will cause:
a. Increase in glomerular filtration rate
b. Decrease in tubular reabsorption
c. Decrease in glomerular filtration rate
d. Increase in renal plasma flow
C
Answer: By virtue of Gibbs-Donnan phenomenon, severe efferent arteriolar vasoconstriction causes decreases GFR. However, slight to moderate resistance increase in efferent arterioles consequently increases GFR.
71
```
The following will cause increased thirst except:
A. Increased osmolarity
B. Decreased blood volume
C. Decreased angiotensin
D. Dryness of mouth
```
C
Answer: Increase in serum osmolarity, decrease in BV, INCREASE angiotensin and dehydration all activate the thirst mechanism.
72
```
A deep sea welder sought consultation to physician because of difficulty of breathing after work. Which of the following will be the most likely cause of his symptom? Pulmonary capillaries are blocked by air bubbles primarily composed of
A. Oxygen
B. Nitrogen
C. Helium
D. Carbon Dioxide
```
B
Answer: Nitrogen comprises the majority of compressed air inhaled from the tank. It is the primary gas being dissolved at high pressures and is the one responsible for decompression sickness with rapid ascent.
73
```
Destruction of parietal cells as seen in chronic gastritis is accompanied by decreased production of HCl and
A. intrinsic factor
B. Pepsin
C. bicarbonate
D. gastrin
```
A
Answer: Instrinsic Factor is produced by the same cell that secretes HCl. Atrophy of these cells cause reduction in B12 absorption in the ileum.
74
```
Which of the following substances would have a renal clearance of 0?
A. inulin
B. para – aminohippuric acid
C. glucose
D. creatinine
```
C
| Answer: Under normal conditions, glucose is fully reabsorbed in the PCT. All the others are secreted in the urine.
75
```
In which of the following nephron segments is the tubular filtrate always hyperosmotic?
A. proximal tubule
B. descending loop of Henle
C. distal tubule
D. medullary collecting duct
```
B
In the descending loop, there is exclusivity in that only water is permeable while solutes are contained within this segment causing hyperosmotic state in the area.
76
```
This condition is LEAST likely to stimulate red cell production:
A. Pulmonary disease
B. Cardiac failure
C. End-stage renal disease
D. Hemorrhagic disease
```
C
| Answer: ESRD causes anemia secondary to reduction or total absence of EPO secretion. Anemia is universal in CKD stage 4.
77
```
An unknown red cell solution that agglutinates with the addition of antisera A and antisera B has the following phenotype:
A. Blood type O
B. Blood type A
C. Blood type B
D. Blood type AB
```
D
| Answer: The presence of both A and B antigens are responsible for reacting with both anti-A and anti-B test serum.
78
```
The following condition/s may have depressed levels of prothrombin resulting to excessive bleeding:
A. Bile duct obstruction
B. Hemophilia
C. Von Willebrand’s disease
D. Hemolytic uremic syndrome
```
A
Answer: Post-hepatic cirrhosis causes reduction in synthesis of vitamin K dependent clotting factors, with prothrombin among them.
79
```
What part of the brain is the principal source of the hormone Serotonin?
A.) Raphe nucleus
B.) Basal nuclei
C.)cerebellum
D.)pineal gland
```
A
80
In an ECG tracing, the P wave corresponds to:
A.)opening of the AV valves and ventricular contraction
B.) Atrial repolarization
C.) Blood flow from the atria to the ventricles
D.) Atrial contraction
D
Answer: Atrial depolarization is the upstroke seen in P wave associated almost immediately with mechanical contraction of the atrium
81
```
What is the main intracellular anion found in the body?
A. Cl-
B. HCO3-
C. Organic anions
D. CN-
E. Histones
```
C
| Chloride ion is the main extracellular anion, organic anions such as porteins are the main intracellular anion.
82
```
During the fasting state, the counter-regulatory hormones predominate to counter the effects of insulin, the main physiologic antagonist of insulin acts through this receptor?
A. G-protein coupled receptors
B. Intracellular receptors
C. Ion-Channel linked receptors
D. Tyrosine kinase receptors
E. Serine/Threonine kinase receptors
```
A
| Glucagon acts throught the cAMP pathway using G-protein coupled receptors.
83
At resting membrane potential both the Na activation gates and the K gates are closed while the Na inactivation gates are open. During depolarization, which gates are opened?
A. N gates closed; M gates closed; H gates open
B. N gates closed; M gates open; H gates open
C. N gates open; M gates open; H gates closed
D. N gates open; M gates closed; H gates closed
E. N gates open; M gates open; H gates open
```
B
N gate= K gates; M gate=Na activation gate; H gates=Na inactivation gates
Choice A= Resting State
Choice B= Depolarization
Choice C= Repolarization
D= Undershoot;
E = Does not exist physiologically
```
84
```
Folding a piece of paper into a paper crane uses coordinated movements that is planned by the cerebral cortex. Which part of the cortex is responsible for planning of these complex tasks?
A. Primary motor cortex
B. Premotor cortex
C. Supplementary motor cortex
D. Posterior parietal cortex
E. Somatosensory cortex
```
C
The motor cortex is responsible for movement but planning and execution of complex tasks require input from the supplementary motor cortex. The premotor cortex keeps track of the location of the trunk and limbs in relation to the task. It plays a role in the spatial guidance of movement. The posterior parietal cortex receives input from the somatosensory cortex, auditory and visual cortex to know the localization of the object and the body in space, and it sends these signals to the supplementary and premotor cortex.
85
```
In the representation known as Traquair's Island of Vision, it describes an island of vision in a sea of darkness representing the visual field of an eye. There is a dark dim pit within the island which is represented by what structure in the eye?
A. Peipheral retina
B. Macula
C. Fovea
D. Optic disk
E. Pupillary aperture
```
D
| The dark dim pit represents the eye's anatomic blindspot which is the optic disk.
86
A patient bleeding profusely was rushed to the ER. A powerful vasoconstrictor in response to the hemorrhage is being secreted by what organ?
A. Supraoptic nucleus of the hypothalamus
B. Paraventricular nucleus of the hypothalamus
C. Anterior Pituitary
D. Posterior Pituitary
E. Pineal gland
D
The question is asking where secretion occurred. ADH is produced in the Supraoptic nucleus, stored and secreted as needed by the posterior pituitary.
87
Which of the following is NOT a characteristic of Fast-twitch muscle fibers in comparison to Slowtwitch muscle fibers?
A. Higher Myosin ATPase activity
B. Extraocular muscles are examples
C. More mitochondria
D. Higher Creatine phosphate levels
E. All are correct about fast-twitch muscles
C
Fast-twitch muscles usually have less mitochondria because they rely mostly in the glycolytic rather than the oxidative pathway.
88
```
Which of the following proteins connects myosin to the Z lines?
A. Titin
B. Dystrophin
C. Actinin
D. Desmin
E. Vimentin
```
A
| Titin is the largest protein and tethers porteins to the Z lines.
89
```
Which of the following parameters should increase to decrease the blood flow?
A. Change in pressure
B. Diameter of the vessel
C. Fluid viscosity
D. Turbulent flow
E. Temperature
```
C
Poiseuille's Law states that Blood flow is directly proportional to pressure difference, radius of the vessel and inversely proportional to fliud viscosity and length of the vessel (determinants of resistance). So to decrease flow, we should increase the determinants of resistance.
90
```
In the cardiac action potential, phase 2 is predominantly attributed to which electrolyte?
A. Na+ influx
B. Na+ efflux
C. Ca+2 influx
D. K+ influx
E. K+ efflux
```
C
Phase 2 of the cardiac action potential is the plateau phase, the primary electrolyte responsible for plateauing of the action potential is Ca influx occuring together with K efflux. K efflux however, is the main electrolyte responsible for the downsloping of phase 3.
91
```
In a normal kidney, subtances are filtered, reabsorbed and secreted through the tubules. Which subtances are filtered and partially reabsorbed?
A. Glucose
B. Amino acid
C. Vitamin C
D. Sodium
E. Creatinine
```
D
Most electrolytes are filtered and partially reabsorbed. Glucose and AA are fully reabsorbed. Vitamin C is secreted. Creatinine is filtered, slightly secreted and not reabsorbed.
92
In a normal kidney, the arterioles are regulated to control the blood flow inspite of changes in blood pressure. Which mechanism of vascular regulation would increase renal blood flow at the cost of glomerular filtration rate?
A. Dilating the afferent arteriole
B. Dilating the efferent arteriole
C. Constricting the afferent arteriole
D. Constricting the efferent arteriole
E. Severe constriction of the efferent arteriole
B
| Dilating the efferent arteriole would increase RBF while decreasing GFR.
93
Acid-base regulation is important to maintain normal pH for the functioning of all enzymes with only a narrow range compatible to life. ABG is important in monitoring the acidbase balance in certain patient populations. ABG results of pH=7.46; PaO2=80 mmHg; HCO3=29 mEq/L; PaCO2=51mmHg; SaO2=95% are compatible with what abnormality?
A. Uncompensated metabolic alkalosis
B. Uncompensated respiratory alkalosis
C. Partially compensated respiratory alkalosis
D. Parially compensated metabolic alkalosis
E. Partially compensated respiratory acidosis
D
Patient has a pH of 7.46 (not between 7.35-7.45), so it is partially compensated and alkalotic. An increase in bicarbonate would mean it is metabolic while an decrease in carbon dioxide would mean it is respiratory. Pls review acid-base derangements, including if it is uncompensated, partially or fully compensated.
94
What is responsible for normal expiration?
A. The negative pressure of the lungs pushes air towards the outside.
B. The diaphragm pushes the lungs upwards initiating expiration.
C. It is an active process that is initiated by the distensibility of the lung.
D. Abdominal muscles are recruited for quiet expiration.
E. The elastic recoil of the chest wall force air out.
E
| Normal expiration is a passive process that is caused by the elastic recoil forces of the lungs and chest wall.
95
```
The central chemoreceptors of the central nervous system are located on the ventrolateral medullary surface. They are necessary in controlling ventilation, which stimulus will trigger the central chemoreceptors?
A. Hypercapnia
B. Hypoxemia
C. Hyperoxemia
D. Hyperventilation
E. Hypoosmolality
```
A
Central chemoreceptors react to increase in carbon dioxide (hypercapnia) and not to hypoxemia, which is responsible for increase firing of the peripheral chemoreceptors.
96
```
A 25 year old woman is enjoying herself to a buffet, celebrating, after having passed the board examination. She is enjoying herself to a welldeserved sumptuous meal, which of the following GI hormones are active a few minutes after having the first bite?
A. Secretin
B. Cholecystokinin
C. Pancreatic polypetide
D. Motilin
E. Histamine
```
E
Histamine and Gastrin would increase stomach acid secretion. Secretin and cholecystokinin are active only once chyme enters the duodenum. Motilin is active only during fasting and PP has no biological function.
97
What is the composition of the pancreatic fluid with regards to plasma?
A. Na+=plasma; K+=plasma; HCO3->plasma; Cl-plasma; K+plasma; Cl-plasma; K+>plasma; HCO3->plasma; Cl->plasma
D. Na+>plasma; K+=plasma; HCO3->plasma; Cl->plasma
E. Na+=plasma; K+=plasma; HCO3->plasma; Cl->plasma
A
Pancreatic fluid consist of sodium and potassium ions that is the same composition of plasma, bicarbonate higher than plasma and chloride ion lower than plasma at any flow rates. At low flow rates, the pancreas secretes an isotonic fluid consists mainly of Na and Cl, at higher flow rates, the pancreas secretes an isotonic fluid that is composed mainly of Na and HCO3-.
98
```
Patient with Graves' Disease have overactive thyroid hormone production due to activating anti-TSH receptor antibody in the cell membranes. The thyroid hormone initiates its action through the use of?
A. Transmembrane receptors
B. Tyrosine kinase receptors
C. Mitochondrial membrane receptors
D. Intracytoplasmic receptors
E. Nuclear receptors
```
E
Thyroid hormones bound to nuclear receptors. Thyroid hormone receptors regulate gene expression by binding to hormone response elements (HREs) in DNA
99
```
Which condition is characterized by increasing aldosterone levels and extracellular fluid volume, but with a decreased in renin levels. There is also no change in sodium urinary excretion?
A. Congestive heart failure
B. Ectopic ACTH secretion
C. Conn's syndrome
D. SIADH
E. Cushing's syndrome
```
C
| These are characteristics of primary aldosteronism, an example of which is Conn's syndrome.
100
In the embryological development, what factor is responsible for the normal physiological development of the female external genitalia?
A. The presence of two X chromosomes.
B. The absence of testosterone.
C. The absence of the Y chromosome
D. The presence of at least one X chromosome, in the abscence of the Y chromosome
E. The absence of the mullerian inhiibiting factor
B
The most important factor in the development of the female external genitalia is the absence of testosterone. The chromosome X and Y is responsible for the development of the gonads. The mullerian inhibiting factor is responsible for development of internal gentalia.
