Pre midterm Flashcards

1
Q
In a normal heart, what is the average direction of the vector during spread of depolarization through the ventricles?
A. -90 degrees
B. 120 degrees 
C. 59 degrees 
D. 275 degrees 
E. 90 degrees
A

C. 59 degrees

  • The vector is an arrow that points in the direction of the electrical potential generated by the current flow.
  • The left hand side of the patient is the zero degrees. As it moves clockwise it becomes positive. Counterclockwise movement makes it negative.
  • The current normally starts at the SA node and flows towards the apex.
  • The measured direction is at around +59 degrees.
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2
Q
Part of the vascular system with largest cross sectional diameter.
A. Capillaries
B. Venules 
C. Aorta 
D. IVC
E. SVC
A

Capillaries

Capillaries-2500 cm2
Venules-250 cm2
Aorta 2.5 cm2

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3
Q
Stretching of the RA has a direct effect on the heart's rhythmicity causing it to beat faster. What mechanism is being described?
A. Frank starling
B. Monroe-kelly 
C. Bainbridge
D. Treppe effect 
E. Butterky effect
A

C. Bainbridge

  • The stretched right atrium initiates a nervous reflex called the bainbridge reflex passing first to the vasomotor center of the brain and then back to the heart by way of the sympathetic nerves and vagus to increase the heart rate.
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4
Q

A patient has Chronic renal disease due to DM. What could possibly describe the effect of the condition on renal function?
A. Inc glomerular filtration coefficient thus inc GFR
B. Inc glomerular colloid osmotic pressure thus inc GFR
C. Dec glomerular filtration coefficient thus dec GFR
D. Dec glomerular capillary colloid osmotic pressure thus dec GFR

A

C. Decreased glomerular filtration coefficient thus decreasing GFR.

  • Chronic renal disease, DM and hypertension may cause a decrease in filtration coefficient thus decreasing GFR.
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5
Q

Signal that limits respiration in response to lung inflation.

A

Hering-breuer reflex

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6
Q

Beta 2 receptor stimulation effect.

A

Bladder wall relaxation

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7
Q
Dorsal column medial lemniscal system conveys what type of stimulus?
A. Vibrations
B. Pain
C. Temperature
D. Tickle
E. Sexual sensations
A

A. Vibrations

  • pain, temp,tickle and sexual sesnsations enters the anterolateral system on its way to the thalamus
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8
Q
Natural gas is usually odorless, but during gas leak from a pipeline a certain odor can be detected. What substance is responsible for the odor?
A. Sulfuric acid
B. Camphor
C. Oil of wintergreen 
D. Methylmercaptan 
E. Indole substances
A

D. Methylmercaptan

*T his substance (methylmercaptan) has a very low threshold for smell thus even the slightest level of gas leaks, (1/trillionth of a gram/mL of air mercaptan is detectable via smell) it can be detected.

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9
Q
Substance that could act as stimulus for CCK secretion.
A. Protein
B. Fat
C. Bicarbonate 
D. Insulin
E. A and B
A

E. A and B (Protein and Fat)

  • CCK secretion Is stimulated by protein, fat and acid in the Small intestines.
  • CCK in turn stimulates panc enzyme secretion, pancreatic bicarbonate secretion, galbladder contraction
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10
Q

The motor impulses from swallowing center to pharynx and upper esophagus that cause swallowing are transmitted successively by the following cranial nerves.

A

5, 9, 10, 12

  • Cranial nerves 5,9,10,12 all participate in the pharyngeal stage of swallowing. Few of the superior cervical nerves also contribute
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11
Q

What peptide hormone function to increase synthesis and release of glucose from the liver and into the body fluids?
A) Glucagon B) Cortisol
C) Aldosterone D) Leptin
E) Insulin

A

A. Glucagon

  • Cortisol is a steroid hormone with anti inflammatory function and regulates metabolism of protein, CHO and fats;
  • Aldosterone is also a steroid hormone which increases renal reabsorption of sodium, promotes potassium secretion, and hydrogen secretion;
  • Leptin- peptide hormone inhibits appetite, stimulates thermogenesis
  • Insulin promotes glucose entry into cells
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12
Q

Hormone that inhibits appetite and stimulate thermogenesis.

A

Leptin

  • Leptin- peptide hormone inhibits appetite, stimulates thermogenesis
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13
Q
If a radius of a blood vessel is doubled, what happens to the rate of blood flood? (Granting all other factors remain
constant)
A. Unchanged
B. Depends upon the pressure C. Doubled
D. Quadrupled
E. None of the above
A

E. None of the above

  • The flow is increased to 16x normal if the radius is doubled. Pouisille’s law. The rate of the flow of blood is directly proportional to the fourth power of the radius.
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14
Q

Which of the following statements is/are true regarding regulation of respiration?
A. The respiratory center is located bilaterally, solely in the medulla oblongata.
B. The pneumotaxic center primarily functions as the “switch-off” point of the inspiration.
C. A strong pneumotaxic signaling decreases the respiratory rate
D. Hering-breuer reflex refers to cough reflex
E. B and C are correct

A

B. The pneumotaxic center primarily functions as the “switch-off” point of the inspiration.

*The respiratory center is located in neurons located both in the medulla and pons; A strong pneumotaxic signal increases the RR, the Hering-breuer reflex refers to a signal that limits respiration in response to lung inflation

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15
Q
Which among the following substanes is not freely filtered by the glomerulus? 
A. Myoglobin
B. Sodium
C. Glucose
D. Inulin
E. None of the above
A

A. Myoglobin

  • Glucose, sodium and inulin are among the substances with filterability equal to that of water.
  • Myoglobin is only partially filtered (75% to that of water)
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16
Q
Majority of the filtered water by the glomerulus is reabsorbed in what renal segment?
A. Proximal convoluted tubule
B. Distal convoluted tubule 
C. Loop of henle
D. Medullary collecting duct 
E. Cortical collecting duct
A

A. Proximal convoluted tubule

*65% of filtered Sodium and Water is reabsorbed at the PCT.

17
Q

Which of the following is true regarding the medullary collecting duct?
A. The final site for urine processing
B. Reabsorbs more than 20% of the filtered water and sodium load.
C. Permeability is dependent upon oxytocin
D. This area is impermeable to urea
E. All are correct

A

A. The final site for urine processing.

*it only reabsorbs less than 10% water and sodium, permeaability is dependent upon ADH, and this segment is permeable to urea

18
Q

Which of the following accurately describes the enteric nervous system?
A. Lies entirely in the wall of the gut
B. Approximately 1 million neurons.
C. Controls the motility and doesn’t regulate secretions.
D. Composed of 2 plexuses the myenteric and the Auerbach’s plexus
E. All of the above

A

A. Lies entirely in the wall of the gut

  • ENS is composed of approx 100 million neurons, Controls motility and secretory function of the gut, composed of myenteric/auerbach and Submucosal/meissner plexus
19
Q

A 26 year old male, born in a tropical country, has recently traveled to antartica, one of the coldest places on earth. Which of the folowing is the body’s response to a sudden change in environmental temperature?
A. Skin vasoconstriction due to stimulation of anterioir hypothalamic centers
B. Piloerection caused by parasympathetic stimulation
C. Increased thermogenesis via shivering, thyroxine production D. A and C are correct
E. All of the above statements are correct

A

C. Increased thermogenesis via shivering, thyroxine production

  • Skin vasoconstriction is due to stimulation of posterior hypotalamus, piloerection is caused by symathetic stimulation.
20
Q
Which among the following hormones uses phospholipase C as secondary messenger?
A. Angiotensin II 
B. Oxytocin
C. NO
D. Transducin
E. A and B
A

E. A and B (AngII & Oxytocin)

  • Angiotensin has 2 effector cells (epithelial-uses cAMP; vascular smooth muscle-uses Phospholipase C);
  • Oxytocin also uses Phospholipase C;
  • NO and transducin uses cGMP.
21
Q
Which of the following conditions/substances stimulate growth hormone secretion?
A. Hyperglycemia 
B. Obesity
C. Somatomedin 
D. Ghrelin
E. Sedentary lifestyle
A

D. Ghrelin

  • Hypoglycemia, decreased blood Free fatty acid levels, increased blood amino acid levels, starvation or fasting, trauma, stress, excitement, exercise, testosterone/estrogen, growth hormone releasing hormone, ghrelin are among the substances that promote GH secretion.
22
Q

Thyroid hormone has an effect in growth and metabolism, which is accurate regarding its function?
A. It promotes glucose absorption in the GI tract
B. Increases fat stores in the body
C. It causesa decrease in vitamin requirement in the body
D. Maintains basal metabolic rate
E. It increases body weight

A

A. It promotes glucose absorption in the GI tract

  • Thyroid hormone promotes glycolysis, gluconeogenesis and increased glucose absorption in the body. It also increases fat mobilization in the body thus decreasing fat stores in general. With increased metabolic rate, the body also needs an increas in vitamin requirement. Increase levels of thyroid hormone decreases body weight.