Physiology Flashcards

1
Q

Which of the ff. Steps w/n the beta cell will bring about insulin secretion?

A. Opening of the K channels by sulfonylureas
B. Closing of calcium channels to prevent influx of calcium
C. Repolarization of the beta cell
D. Increase in intracellular calcium
E. None of the above

A

D

*depolarization opens calcium channels which will lead to an INCREASE IN INTRACElLULAR CALCIUM and then to secretion of insulin

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2
Q

This type of intracellular structures between cell membranes is responsible for tight intercellular adhesions:

A

Macula adherens

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3
Q

In the cardiac action potential, phase 2 is characterized by:

A

Calcium influx

  • Phase 0 - influx of Na
  • Phase 1 - transient efflux of K
  • Phase 2 - influx of Ca and Na
  • Phase 3 - efflux of K> influx of Ca and Na
  • Phase 4 - Na-K pump

*Ivabradin (Corlnor)- slows down the HR by targeting the Na (If) Channels

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4
Q

This tactile receptor receives steady-state signal for continuous touch and determines texture:

A

Merkel disc

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5
Q

These cells are output cells of the retina in which axons form the optic nerve

A

Ganglion cells

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6
Q

What cells maintains the internal geometry of the retina

A

Mueller cells

*Bipolar cells, Amacrine and horizontal cells- interneurons

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7
Q

Blood flow per grams of tissue is greatest in which organ

A

Kidney

*20% of cardiac output

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8
Q

In the atrial pressure curve, this is represented by venous blood going to the atria:

A. A wave
B. C wave
C. V wave
D. X descent
E. Y descent
A

C

  • A wave- atrial contraction
  • C wave- contraction of the ventricle (bulging of the tricuspid valve)
  • V wave- venous blood going to atria; back-pressure wave from blood filling the right atrium
  • X descent- drop in atrial pressure during ventricular systole caused by atrial relaxation
  • Y descent- caused by early ventricular filling

Tricuspid regurgitation- giant (V) waves, CV wave

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9
Q

Atrial fibrillation

A

Absent a wave

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10
Q

Heart block, prominent A waves

A

Cannon waves

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11
Q

Cushing reflex triad

A

Hypertension
Bradycardia
Irregular respirations/ bradypnea

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12
Q

Oxygen-hemoglobin dissociation curve. Shift to the right:

A
Increased P50
Acidosis/ dec PH
Increase temp
Increase PCO2
Increase 2,3-BPG bisphosphoglycerate
increase altitude

Right=Release
O2 released easily

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13
Q

Respiratory responses to high altitude

A
Dec. alveolar PO2
Dec. Arterial PO2
Inc. pulmonary vascular resistance - because of hypoxic vasoconstriction
Inc. arterial pH
Inc. respiratory rate
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14
Q

Part of the nephron most susceptible to hypoxia and toxins and is considered as the WORKHORSE of the nephron

A

Proximal convoluted tubule

*reabsorption usually happens here

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15
Q

Vomiting center in the medulla oblongata is called

A

Area postrema

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16
Q

Gastrointestinal secretion inhibited when the pH of the stomach contents is 1.0

A

Gastric secretion- by the G cells

17
Q

after a full meal, acidic contents empty into the duodenum. These Acidic contents will stimulate:

A

Pancreatic secretion

18
Q

Enzyme responsible for peripheral conversion of T4 to T3

A

D1 thyroid deiodinase

  • T4 longer halflife (as long as 7 days) - give T4 drug (e.g. Levothyroxin) for px with Hypothyroidism
  • drug that could inhibit T4–>T3 :
    1. PTU
    2. Propranolol
    3. Steroids (hydrocortisone/prednisone)

*more biologically active- T3

Hyperthyroidism
Tx: PTU, Methimazole
PTU indications:
Thyroid storm, 1st tri of pregnancy, severe allergy to Methimazole

Methimazole is more preferred but has A.E. in babies- Cutis aplasia
A.E in adult px: Agranulocytosis

19
Q

Major form of estrogen seen in post-menopausal period

A

Estrone

  • reproductive years (husband & wife) 2 persons- EstraDIol
  • pregnancy (husband, wife & baby) 3 persons- EsTRIol
20
Q

Protease that inhibits serum endoproteases

A

Alpha 2 macroglobulin

21
Q

This type of antibody is known to have the greatest avidity

A

IgM

  • avidity is the accumulated strength of multiple affinities of an antibody
  • affinity- single antigen-antibody interaction
22
Q

Structure of IgM

A

Pentameric

*biggest Ig

23
Q

Absence of H antigen in RBC is designated as what blood type?

A

Ans: Bombay blood type or Bombay blood group (hh)
NOT TYPE O!!
normal is HH/ Hh

  • persons blood type is dependent on the sugar moiety which is attached to the parent molecule
  • Blood type O has the presence of H antigen with no other attached Sugar moiety
  • H antigen- encodes for the fucosyl transferase—> Fucose
  • sugar of A antigen- N-acetylgalactosamine
  • B antigen- D-Galactose
24
Q

Vitamin K dependent factors, shortest half-life

A

Factor VII

*Vit. K dependent factor:
2, 7, 9, 10, protein C, S, Z
- they are also Calcium requiring

25
Q

Site where systolic BP is highest

A

Renal artery

*BP is higher as you go downstream, higher than in the aora