Competitive Exams: Medical Science MCQs (Practice-Test 79 of 135)

  1. To which one or the following events in the heart does the PH interval in ECG training correspond?

    1. Cardiac impulse reaching AV node

    2. Cardiac impulse generation in SA node

    3. Atrail depolarization and conduction through AV node

    4. Atrail depolarisation

  2. Respiratory centres in the brain stem show decreased sensitivity to P CO2 during

    1. Slow-wave sleep

    2. Mental concentration

    3. Physical exercise

    4. Voluntary hyperventilation

  3. Consider the following statements: AV Nodal delay

    1. allows atrial to get filled adequately

    2. allows atrial systole to be over

    3. is due to less nexi between AV Nodal fibres.

    Which of the statemtns given above are correct?

    1. 1, 2 and 3

    2. 1 and 3

    3. 2 and 3

    4. 1 and 3

  4. In a heart beating at 72 times/minute the absolute refractor period is

    1. 3 milliseconds

    2. 30 milliseconds

    3. 300 milliseconds

    4. 3 Seconds

  5. The sequence of steps in muscle relaxation is

    1. Release of Ca2 + from troponin, Ca2 + pumped back in sarcoplasmic reticulum, cessation of interaction between actin and myosin

    2. Release of Ca2 + from troponin, cessation of interaction between actin and myosin, Ca2 + pumped back in sarcoplasmic reticulum

    3. Ca2 + pumped back in sarcoplasmic reticulum, release of Ca2 + from troponin, cessation of interaction between actin and myosin

    4. Cessation of interaction between actin and myosin, release of Ca2 + from troponin, Ca2 + pumped back in sarcoplasmic reticulum

  6. Ovulation occurs

    1. immediately after LH peak

    2. nine hours after LH peak

    3. during early part of follicular phas

    4. three hours after LH peak

  7. The over-expression of a trinucleotide repeat causes

    1. Parkinsons disease

    2. Caissons disease

    3. Addisons disease

    4. Huntingtons disease

  8. Which one of the following factors is stimulant of both peripheral and central chemoreceptors causing increased ventilation?

    1. A decrease in arterial oxygen content

    2. An increase in arterial CO2 tension

    3. A decrease in arterial O2 tension

    4. An increase in arterial blood pH

  9. the excitatory signals from Pontine reticular formation are normally inhibited by

    1. vestibular nuclei

    2. cerebellar nuclei

    3. Medullary reticular formation

    4. Basal ganglia

  10. Stimulation of which one of the following can produce sleep?

    1. Posterior hypothalamus

    2. Medullary reticular formation

    3. Gracile and cuneate nuclei

    4. Occipital cortex

  11. Match List I (Sensory Receptor) with List II (Response elicited) and select the correct answer using the codes:

    List-I List-II
    1. Muscle spindle

    2. Free nerve endings

    3. Gustatory receptors

    4. Labyrinthine receptors

    1. Postural adjustment salivation

    2. Muscle contraction

    3. Muscle contraction

    4. Withdrawl response

    5. Muscle relaxation

    • A
    • B
    • C
    • D
      • 1
      • 4
      • 3
      • 2
      • 1
      • 5
      • 3
      • 2
      • 3
      • 1
      • 2
      • 4
      • 3
      • 5
      • 2
      • 1
  12. Consider the following diseases:

    1. Hymenolepis nana infection

    2. Endemic typhus

    3. Trench fever

    Which of the above is/are transmitted by rat flea?

    1. 1 and 2

    2. 2 and 3

    3. 2 only

    4. 1 and 3

  13. Consider the following kinds of substances:

    1. Adhesion molecules

    2. Chemical mediators

    3. bacterial antigens

    4. Toxic oxygen radicals

    Which of the above determine leucocyte adhesion and transmigration in inflammation?

    1. 1 only

    2. 1 and 2

    3. 2, 3 and 4

    4. 3 and 4

  14. Which one of the following is not a macrophage product?

    1. Tumour necrosis factor (TNF)

    2. Interleukin I

    3. Bradykinin

    4. Lysozyme

  15. Consider the following statements: The histologic identity of chronic inflammation constitute

    1. Infiltration of tissue by mononuclear cells

    2. Exudation of fluid in the tissue

    3. Proliferation of fluid in the tissue

    4. proliferation of fibroblasts

    Which of the statements given above are correct?

    1. 1, 2 and 3

    2. 2, 3 and 4

    3. 1, 3 and 4

    4. 1, 2 and 4