Module 4 - Nervous System and Muscle Flashcards

1
Q

Glial cells are important cells of the CNS. Which type of glial cell is involved in myelin formation around axons in the peripheral nervous system?

  1. Microglia
  2. Schwann cell
  3. Fibrous astrocyte
  4. Astrocyte
  5. Oligodendrocyte
A

Schwann cell

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2
Q

A patient has presented to the pre-operative clinic. He has been chronically hypocalcaemic due to kidney failure. What is the effect of hypocalcaemia (decrease in extracellular calcium) on the action potential of a nerve cell?

  1. The neuron becomes less excitable
  2. The neuron becomes more excitable
  3. The resting membrane potential is unaffected
  4. The size of the action potential is reduced
  5. The size of the action potential is increased
A

The neuron becomes more excitable

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3
Q

How is the sharp initial pain associated with injury transmitted?

  1. Through nerve fibres that move briefly through the dorsolateral fasciculus
  2. Through unmyelinated Aδ fibres
  3. By antidromic propagation
  4. Through nerve fibres that project to the anterior horn of the spinal cord
  5. Through unmyelinated C fibres
A

Through nerve fibres that move briefly through the dorsolateral fasciculus

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4
Q

All dopamine receptors are of which type?

  1. DAG linked receptors
  2. Phospholipase C coupled receptors
  3. Ligand gated ion channels
  4. Metabotropic G protein coupled receptors
  5. Enzyme-linked cell surface receptors
A

Metabotropic G protein coupled receptors

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5
Q

Which neurons in the autonomic nervous system release noradrenaline?

  1. Parasympathetic preganglionic neurons in the sweat glands
  2. Sympathetic postganglionic neurons in the sweat glands
  3. Parasympathetic preganglionic neurons in the small intestine
  4. Sympathetic preganglionic neurons in the sweat glands
  5. Sympathetic postganglionic neurons in the small intestine
A

Sympathetic postganglionic neurons in the small intestine

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6
Q

Which of the following is a sympathetic response?

  1. Relaxation of the gall bladder
  2. Contraction of the detrusor muscle of the urinary bladder
  3. Contraction of the sphincter muscle of the iris
  4. Relaxation of sphincters of the stomach and intestine
  5. Contraction of ciliary muscle of the eye
A

Relaxation of the gall bladder

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7
Q

A patient presents to the emergency department after consuming a large quantity of an unknown species of mushroom during a bushwalk. Mushroom poisoning can result in what clinical syndrome/s?

  1. Nicotinic syndrome
  2. Muscarinic poisoning and anti-muscarinic syndrome
  3. Muscarinic poisoning
  4. Muscarinic poisoning, nicotinic syndrome and anti-muscarinic syndrome
  5. Anti-muscarinic syndrome
A

Muscarinic poisoning and anti-muscarinic syndrome

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8
Q

Which of the following would terminate the action of noradrenaline?

  1. Catechol-O-methyltransferase in presynaptic noradrenergic neurons
  2. Monoamine oxidase in the nerve terminal
  3. Phenylethanolamine-N-methyltransferase in the nerve terminal
  4. Dopa decarboxylase in the nerve terminal
  5. Dopamine-β-hydroxylase in the chromaffin cells
A

Monoamine oxidase in the nerve terminal

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9
Q

Repolarization of a skeletal muscle fibre is largely due to the specific movement of what ion?

  1. K+ efflux
  2. Na+ influx
  3. Ca+ influx
  4. Ca+ efflux
  5. K+ influx
A

K+ efflux

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10
Q

What would be an expected outcome of ϒ–motor neuron discharge, in response to a noxious stimulus on the skin?

  1. Increased efferent discharge to ipsilateral flexor muscle spindles
  2. Decreased efferent discharge to flexor and extensor muscle spindles
  3. Increased efferent and afferent discharge to extensor muscle spindles
  4. Increased efferent discharge to ipsilateral extensor muscle spindles
  5. Decreased efferent discharge to ipsilateral flexor muscle spindles
A

Increased efferent discharge to ipsilateral flexor muscle spindles

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11
Q

The heat produced in muscles can be measured with thermocouples. What is the term given to the heat liberated by the metabolic processes that restore the muscle to its pre-contraction state?

  1. Resting heat
  2. Recovery heat
  3. Shortening heat
  4. Relaxation heat
  5. Activation heat
A

Recovery heat

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12
Q

Regarding electrical events in postsynaptic neurons, which ion might be responsible for mediating the IPSP (inhibitory postsynaptic potential)?

  1. H+
  2. Ca2+
  3. Na+
  4. Mg2+
  5. Cl-
A

Cl-

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13
Q

NREM sleep is divided into stages. At what stage of NREM sleep would you expect to find sleep spindles on an EEG?

  1. Stage 3
  2. Stage 5
  3. Stage 2
  4. Stage 4
  5. Stage 1
A

Stage 2

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14
Q

What is the approximate rate of CSF production in a healthy adult?

  1. 750mL/day
  2. 550mL/day
  3. 400mL/day
  4. 150mL/day
  5. 250mL/day
A

550mL/day

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15
Q

In the brain, autoregulation maintains a normal cerebral blood flow at what arterial pressures?

  1. 100-150 mmHg
  2. 65-140 mmHg
  3. 50-100 mmHg
  4. 20-50 mmHg
  5. 120-160 mmHg
A

65-140 mmHg

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16
Q

There are three classes of opioid receptors u, k and d. They differ in physiologic effects and affinity for various opioid peptides.

Match the opioid receptor with the corresponding endogenous opioid peptide affinity.

  1. Enkephalins > Endorphins and Dynorphins
  2. Endorphins > Enkephalins > Dynorphins
  3. Dynorphins >> Endorphine and Enkephalins
A
  1. Kappa
  2. Mu
  3. Delta
17
Q

Which of the following is characteristic of the blood supply for the spinal cord?

  1. The anterior spinal artery is a branch of the basilar artery
  2. The anterior spinal artery supplies the anterior one third of the spinal cord
  3. The posterior spinal artery has poor collateral supply from the radicular arteries
  4. There are two posterior spinal arteries and one anterior spinal artery
  5. The anterior spinal artery has a good collateral supply in the cervical region from the artery of Adamkiewicz
A

There are two posterior spinal arteries and one anterior spinal artery

18
Q

How is the sharp initial pain associated with injury transmitted?

  1. By antidromic propagation
  2. Through unmyelinated Aδ fibres
  3. Through unmyelinated C fibres
  4. Through nerve fibres that project to the anterior horn of the spinal cord
  5. Through nerve fibres that move briefly through the dorsolateral fasciculus
A

Through nerve fibres that move briefly through the dorsolateral fasciculus

19
Q

The cell membrane of nerve cells functions via ionic fluxes to make an action potential. What channel openings and closures bring about the absolute refractory period?

  1. Na+ channels reset and K+ channels open
  2. Na+ channels close and K+ channels open
  3. Both Na+ and K+ channels close
  4. Na+ channels open
  5. Both Na+ and K+ channels open
A

Na+ channels close and K+ channels open

20
Q

Which of the following would terminate the action of noradrenaline?

  1. Catechol-O-methyltransferase in presynaptic noradrenergic neurons
  2. Dopa decarboxylase in the nerve terminal
  3. Monoamine oxidase in the nerve terminal
  4. Dopamine-β-hydroxylase in the chromaffin cells
  5. Phenylethanolamine-N-methyltransferase in the nerve terminal
A

Monoamine oxidase in the nerve terminal

21
Q

Dopamine is synthesised from what precursor?

  1. Noradrenaline
  2. Adrenaline
  3. Tyrosine
  4. Isoprenaline
  5. Dobutamine
A

Tyrosine

22
Q

What is the function of the intrafusal fibres in skeletal muscle?

  1. Pure sensory function
  2. Small contribution to overall contractile force of the muscle
  3. Major contribution to the overall contractile force of the muscle
  4. Provide all contractile force for of the muscle
  5. Storage and release of neurotransmitters
A

Pure sensory function

23
Q

What properties (specifically myosin ATPase activity, oxidative or glycolytic capacity, and colour) does a slow twitch skeletal muscle possess?

  1. Fast, oxidative, red in colour
  2. Fast, glycolytic, white in colour
  3. Slow, oxidative, white in colour
  4. Slow, oxidative, red in colour
  5. Fast, glycolytic, red in colour
A

Slow, oxidative, red in colour

24
Q

What happens during the latch state in smooth muscle?

  1. Myosin and actin cross-bridges detach after the initial power stroke
  2. ATP consumption continues as the force of contraction is maintained
  3. Intracellular calcium levels in the smooth muscle cells rises slowly
  4. The smooth muscle cell relaxes on contact with NO (nitric oxide)
  5. Actin and myosin cross-bridges remain attached as ATP consumption declines
A

Actin and myosin cross-bridges remain attached as ATP consumption declines

25
Q

What is the location of the Golgi tendon organ?

  1. Within the muscle spindle
  2. Perpendicular to muscle fibres
  3. In series with the muscle fibres
  4. Adjacent to the muscle tendon
  5. Perpendicular with the muscle tendon
A

In series with the muscle fibres

26
Q

What happens during skeletal muscle contraction?

  1. Myosin heads cross-link with actin and swivel 90º
  2. There is an interaction between actin and tropomyosin
  3. Calcium diffuses back into the sarcoplasmic reticulum at the end of contraction
  4. Z lines move closer together during contraction
  5. Troponin C inhibits the interaction of myosin with actin
A

Z lines move closer together during contraction

27
Q

What pattern is most commonly seen on the EEG of an awake adult who is at rest with their eyes closed?

  1. Alpha rhythm
  2. Beta rhythm
  3. Gamma oscillations
  4. Theta rhythm
  5. Delta rhythm
A

Alpha rhythm

28
Q

What increases cerebral blood flow in a normal person?

  1. Movement from the supine to the head down position
  2. Increase in the mean arterial pressure from 80 to 110 mmHg
  3. Increase in the arterial PCO2 from 35 to 45 mmHg
  4. Increase in the intracranial pressure from 10 to 20 mmHg
  5. Decrease in the arterial PO2 from 80 to 60 mmHg
A

Increase in the arterial PCO2 from 35 to 45 mmHg

29
Q

Glial cells are important cells of the CNS. Which type of glial cell is involved in myelin formation around axons in the CNS?

  1. Oligodendrocyte
  2. Schwann cell
  3. Astrocyte
  4. Fibrous astrocyte
  5. Microglia
A

Oligodendrocyte

30
Q

Which of the following is usually an excitatory neurotransmitter?

  1. Glycine
  2. Dopamine
  3. GABA
  4. Glutamate
  5. Serotonin
A

Glutamate

31
Q

The flow of information that leads to smooth muscle contraction is made up of many steps. The following is an out of order list of steps that in sequence will lead to contraction of smooth muscle.

  1. Activation of calmodulin-dependent myosin light chain kinase
  2. Increased myosin ATPase activity and binding of myosin to actin
  3. Phosphorylation of myosin
  4. Increased influx of calcium Ca+ into cell

Order the above steps in the correct sequence following the binding of acetylcholine to muscarinic receptors and ending in contraction of smooth muscle.

Initial event - Binding of acetylcholine to muscarinic receptors

End result - Contraction of smooth muscle

A

Step 1 - Increased influx of calcium Ca+ into cell

Step 2 - Activation of calmodulin-dependent myosin light chain kinase

Step 3 - Phosphorylation of myosin

Step 4 - Increased myosin ATPase activity and binding of myosin to actin