Exercise and neuromuscular physiology

48 Gulf Prometric Physiotherapist (DHA, DOH, MOH, SCFHS, QCHP) practice questions on Exercise and neuromuscular physiology, part of Anatomy and Physiology. The first 25 are below; the first 5 with answers and explanations (tap Show answer after you have chosen), the rest in Learn with a free account.

1. Question 1 · Medium

   A patient performs a sustained maximal isometric hand-grip with breath-holding. What effect on blood pressure is expected?

   1. AMarked rise in both systolic and diastolic pressure
   2. BFall in both pressures
   3. CNo change in either pressure
   4. DRise in systolic with falling diastolic

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   Answer: A · Marked rise in both systolic and diastolic pressure

   Static contraction compresses the vessels and increases peripheral resistance, and the Valsalva manoeuvre raises intrathoracic pressure, so both pressures rise disproportionately for the oxygen cost. This is why resisted breath-holding is avoided in hypertensive and cardiac patients.

   • B: A fall is not typical of static work.
   • C: Pressures change noticeably.
   • D: Systolic with falling diastolic is the pattern of dynamic exercise.

   Remember this

   Static effort with breath-holding raises both systolic and diastolic pressure sharply.

2. Question 2 · Easy

   During dynamic exercise like jogging, what happens to systolic blood pressure?

   1. AIt falls steadily
   2. BIt stays exactly at the resting value
   3. CIt falls to zero at peak effort
   4. DIt rises with intensity

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   Answer: D · It rises with intensity

   Cardiac output increases more than peripheral resistance falls, so systolic pressure rises in proportion to workload, up to about 200 mmHg or more at maximum. Diastolic pressure stays about the same or falls slightly. A fall in systolic pressure with increasing load is abnormal.

   • A: A steady fall would be abnormal and signal poor cardiac reserve.
   • B: It does not stay constant because output rises.
   • C: Zero is not compatible with life.

   Remember this

   Systolic pressure rises with dynamic workload; a fall is abnormal.

3. Question 3 · Easy

   Which nerve fibres carry the fast, sharp first pain after a pinprick?

   1. AA-delta fibres
   2. BC fibres
   3. CA-alpha fibres
   4. DA-beta fibres

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   Answer: A · A-delta fibres

   A-delta fibres are thinly myelinated and conduct at about 5-30 m/s, giving well-localised sharp pain. Slower unmyelinated C fibres give a dull, burning second pain. Both end in the dorsal horn.

   • B: C fibres carry the slow, dull second pain.
   • C: A-alpha fibres carry proprioception and motor output.
   • D: A-beta fibres carry touch and pressure.

   Remember this

   A-delta fibres carry fast sharp pain; C fibres carry slow dull pain.

4. Question 4 · Hard

   A trained 400 m runner finishes in about 50 seconds. Which statement best describes the ATP supply over the full race?

   1. AMostly fat oxidation, as the race lasts nearly a minute
   2. BAlmost entirely phosphocreatine, which lasts the whole race
   3. CMostly anaerobic (glycolysis plus phosphocreatine), with a sizeable aerobic share
   4. DAlmost entirely aerobic, with only a trivial anaerobic share

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   Answer: C · Mostly anaerobic (glycolysis plus phosphocreatine), with a sizeable aerobic share

   An all-out effort of about 50 seconds draws most of its ATP from anaerobic glycolysis, with phosphocreatine covering the first seconds. Studies place the aerobic share at roughly 30 to 45 percent, so it is substantial but not the majority. Lactate and hydrogen ion build-up drive the fatigue.

   • A: Fat oxidation is far too slow to supply ATP at this intensity.
   • B: Phosphocreatine stores fall within about 10 seconds of maximal work.
   • D: The aerobic share is substantial but below half at this duration.

   Remember this

   A 400 m race is mainly anaerobic, with a substantial aerobic contribution.

5. Question 5 · Hard

   Repeated C-fibre stimulation at about 1 Hz causes a progressive increase in dorsal horn neuron output. Which receptor is mainly involved in this wind-up?

   1. ANicotinic receptor
   2. BNMDA glutamate receptor
   3. CGABA-A receptor
   4. DMu opioid receptor

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   Answer: B · NMDA glutamate receptor

   Repeated C-fibre input releases glutamate and substance P, removes the magnesium block from the NMDA receptor, and increases the response of dorsal horn neurons. This wind-up is one mechanism of central sensitisation. NMDA antagonists such as ketamine interfere with it.

   • A: Nicotinic receptors work at the neuromuscular junction and ganglia.
   • C: GABA-A receptors are inhibitory.
   • D: Mu opioid receptors reduce pain transmission and are the target of morphine.

   Remember this

   Wind-up and central sensitisation involve NMDA receptors.

6. Question 6 · Hard

   During a treadmill test a client develops moderate angina, and the systolic pressure falls 12 mmHg below baseline as the speed increases. What should the therapist do?

   1. AContinue, as only a fall of 20 mmHg or more needs stopping
   2. BRepeat the blood pressure after the next stage before deciding
   3. CStop the test, as this is an absolute indication to terminate
   4. DIncrease the workload to confirm that the response is real

   Answer and explanation in LearnFree account

7. Question 7 · Medium

   A recreational runner in Doha has severe thigh pain two days after a downhill race. Which type of muscle contraction is the main cause?

   1. AIsotonic with no load
   2. BIsometric
   3. CConcentric
   4. DEccentric

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8. Question 8 · Medium

   Which change occurs in a regular endurance athlete's fibre composition after long training?

   1. AMuscle fibres are lost in large numbers
   2. BType I fibres convert fully into type IIx fibres
   3. CSome type IIx fibres take on type IIa properties
   4. DCapillary density falls in the trained muscle

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9. Question 9 · Easy

   Which receptor in muscle detects the rate and amount of stretch?

   1. APacinian corpuscle
   2. BFree nerve ending
   3. CGolgi tendon organ
   4. DMuscle spindle

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10. Question 10 · Medium

    Which statement about Golgi tendon organ input is correct when a muscle contracts with great tension?

    1. AIt only carries pain
    2. BIt excites the same muscle strongly
    3. CIt inhibits the contracting muscle through Ib interneurons
    4. DIt has no effect on spinal motor neurons

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11. Question 11 · Medium

    How does force production change with increasing speed of concentric contraction?

    1. AIt increases
    2. BIt stays constant
    3. CIt decreases
    4. DIt becomes maximal at the highest speed

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12. Question 12 · Easy

    Which equation correctly gives cardiac output?

    1. AHeart rate + stroke volume
    2. BMean arterial pressure x heart rate
    3. CStroke volume divided by heart rate
    4. DHeart rate x stroke volume

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13. Question 13 · Medium

    How many ATP molecules are gained net when one glucose is broken down by glycolysis without oxygen?

    1. A36 ATP
    2. B2 ATP
    3. C4 ATP net
    4. D30-32 ATP

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14. Question 14 · Medium

    What is the role of gamma motor neurons during muscle contraction?

    1. AThey cause the main force of contraction
    2. BThey keep the muscle spindle taut so it remains sensitive
    3. CThey carry pain signals
    4. DThey inhibit antagonist muscles

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15. Question 15 · Medium

    A woman with a healed ankle injury still reports pain with light pressure over a wide area of the leg. Which mechanism best explains this?

    1. ARaised pain thresholds in the central pathways
    2. BLoss of neurons in the dorsal horn of the cord
    3. CContinuing damage to the peripheral nociceptors
    4. DAmplified responses of central pain neurons to normal input

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16. Question 16 · Easy

    Which receptor detects the tension that a muscle develops at the tendon?

    1. ARuffini ending in skin
    2. BGolgi tendon organ
    3. CMeissner corpuscle
    4. DMuscle spindle

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17. Question 17 · Easy

    Which energy system supplies most of the ATP during a 60-minute walk at a comfortable pace?

    1. AAnaerobic glycolysis
    2. BAerobic system
    3. CMyokinase system only
    4. DATP-phosphocreatine system

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18. Question 18 · Medium

    Increased venous return causes the ventricle to eject more blood. Which principle explains this?

    1. AFrank-Starling mechanism
    2. BBainbridge reflex
    3. CBaroreceptor reflex
    4. DBowditch effect

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19. Question 19 · Hard

    During steady submaximal exercise, a client's respiratory exchange ratio (RER) is 0.85. What does this suggest about fuel use?

    1. AWork above the point where buffering raises CO2 output
    2. BOxidation of carbohydrate alone, with no fat use
    3. COxidation of fat alone, with no carbohydrate use
    4. DA roughly equal mix of fat and carbohydrate oxidation

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20. Question 20 · Medium

    In myasthenia gravis, antibodies reduce the receptors for which transmitter at the motor end plate?

    1. AAcetylcholine
    2. BGABA
    3. CNoradrenaline
    4. DDopamine

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21. Question 21 · Medium

    One metabolic equivalent (1 MET) is defined as an oxygen uptake of:

    1. A1 L/min
    2. B0.35 mL/kg/min
    3. C35 mL/kg/min
    4. D3.5 mL/kg/min

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22. Question 22 · Medium

    After a nerve injury, a light touch on a woman's forearm causes severe pain. How is this described?

    1. AHypoaesthesia
    2. BParaesthesia
    3. CAllodynia
    4. DHyperalgesia

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23. Question 23 · Medium

    During a graded exercise test, a young man reaches a point where blood lactate begins to rise sharply. What does this point represent?

    1. ALactate threshold
    2. BOnset of muscle hypertrophy
    3. CEnd of aerobic metabolism
    4. DMaximal heart rate

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24. Question 24 · Easy

    According to the gate control theory, which input can close the pain gate in the dorsal horn?

    1. AMotor axons of the anterior horn
    2. BSympathetic efferents
    3. CSmall unmyelinated C fibres
    4. DLarge-diameter A-beta touch fibres

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25. Question 25 · Easy

    Which muscle fibre type is slow-twitch, rich in mitochondria and resistant to fatigue?

    1. AType IIa
    2. BType I
    3. CType IIx
    4. DType IIb only

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