Deck 9: Skeletal Muscle Relaxants

Question 1

Austin has accidently taken an overdose of atracurium,a drug belonging to the class of nondepolarizing blockers.He slips into a state of respiratory paralysis and struggles to control his breathing.On arriving at the hospital,the doctors give Austin a dose of a certain drug in an attempt to reverse his condition.Based on the information provided in this scenario,which of the following drugs have the doctors given Austin?

A) Atropine
B) Oxybutynin
C) Neostigmine
D) Scopolamine

Answer 1

Neostigmine

Question 2

Identify a difference between nondepolarizing blockers and depolarizing blockers.

A) The nondepolarizing blockers stimulate the nicotinic-muscle (Nm) receptors, whereas the depolarizing blockers do not.
B) The nondepolarizing blockers inhibit cholinergic activity by occupying the nicotinic-muscle sites so that acetylcholine (ACH) cannot bind with the receptors, whereas depolarizing blockers inhibit cholinergic activity by altering the Nm receptors so that they cannot respond to ACH stimulation.
C) The nondepolarizing blockers inhibit cholinergic activity by attaching themselves to the synaptic vesicles containing ACH and preventing ACH from being released into the synaptic cleft, whereas depolarizing blockers inhibit cholinergic activity by occupying the nicotinic-muscle sites so that acetylcholine (ACH) cannot bind with the receptors.
D) The nondepolarizing blockers combine with the Nm receptors, whereas the depolarizing blockers do not.

Answer 2

The nondepolarizing blockers inhibit cholinergic activity by occupying the nicotinic-muscle sites so that acetylcholine (ACH) cannot bind with the receptors, whereas depolarizing blockers inhibit cholinergic activity by altering the Nm receptors so that they cannot respond to ACH stimulation.

Question 3

The major toxicity associated with neuromuscular blocker overdose is:

A) respiratory muscle paralysis.
B) cardiovascular collapse.
C) hypercalcemia.
D) hyponatremia.

Answer 3

respiratory muscle paralysis.

Question 4

Neuromuscular blockers inhibit skeletal muscle contraction by interfering with the _____.

A) nicotinic-muscle receptors
B) nicotinic-neural receptors
C) muscarinic receptors
D) ganglionic receptors

Question 5

Which of the following types of drugs inhibits muscle contraction at the neuromuscular junction or within the contractile process?

A) Spasmolytics
B) Peripheral skeletal muscle relaxants
C) Parasympathomimetic drugs
D) Cholinergic drugs

Question 6

The drug dantrolene relaxes skeletal muscle by inhibiting the release of which ions from the sarcoplasmic reticulum?

A) Sodium ions
B) Chloride ions
C) Potassium ions
D) Calcium ions

Question 7

Which of the following types of skeletal muscle relaxants can be considered a cholinergic receptor antagonist?

A) A nondepolarizing drug
B) A depolarizing drug
C) A direct-acting cholinergic drug
D) An indirect-acting cholinergic drug

Question 8

The two types of receptors that can be manipulated to reduce spasticity are the:

A) alpha-1 adrenergic receptors and the GABA receptors.
B) the serotonin receptors and the GABA receptors.
C) the histamine receptors and the cholinergic receptors.
D) the alpha-2 adrenergic receptors and the GABA receptors.

Question 9

One of the ways to prolong the effects of a rapidly metabolized skeletal muscle relaxant is to administer the medication:

A) through an intravenous injection.
B) by intravenous infusion.
C) through an intramuscular injection.
D) intradermally.

Question 10

The binding of the neurotransmitter acetylcholine to the nicotinic-muscle receptors at the neuromuscular junction enables:

A) potassium ions to move into the cells.
B) sodium ions to move out of the cells.
C) sodium ions to move into the cells.
D) magnesium ions to enter the cells.

Question 11

Which of the following muscles are the first to become relaxed after the administration of a low dose of a nondepolarizing muscle relaxant?

A) The muscles of the eyes and face
B) The muscles of the limbs
C) The muscles of the trunk
D) The muscles of the diaphragm

Question 12

Ella has been taking large doses of a particular neuromuscular blocker over a very long period of time.Consequently,she has developed signs of respiratory paralysis and has severe trouble breathing.After Dr.Kurt examines her,he concludes that Ella's deteriorating health is the result of the growing concentration of the neuromuscular blocker drug in her system.He prescribes the drug neostigmine to relieve her symptoms.How will the drug neostigmine help counteract the effects of the neuromuscular blocker drug?

A) It will inhibit the enzyme acetylcholinesterase so that acetylcholine (ACH) accumulates within the synaptic junctions.
B) It will attach itself to the synaptic vesicles containing ACH and prevent ACH from being released into the synaptic cleft.
C) It will damage the nicotinic-muscle receptors, thereby altering the ability of these receptors to become stimulated.
D) It will enhance the activity of the enzyme acetylcholinesterase so that the concentration of ACH in the synaptic cleft decreases.

Question 13

Drugs that inhibit skeletal muscle contraction by blocking conduction within the spinal cord are known as _____.

A) spasmolytics
B) peripheral skeletal muscle relaxants
C) cholinergic drugs
D) parasympathomimetics

Question 14

The antidote that is administered for depolarizing neuromuscular blocker toxicity is:

A) pancuronium.
B) succinylcholine.
C) demecarium.
D) No antidote is available.

Question 15

_____ is the only available depolarizing neuromuscular blocking drug.

A) Pancuronium
B) Atracurium
C) Succinylcholine
D) Carbachol

Question 16

Which of the following statements is true of nondepolarizing blockers?

A) The nondepolarizing blockers combine with, but do not stimulate, the nicotinic-muscle (Nm) receptors.
B) The nondepolarizing blockers allow acetylcholine to combine with the Nm receptors to induce depolarization.
C) The only available nondepolarizing neuromuscular blocking drug available today is succinylcholine.
D) After binding to the Nm receptors, nondepolarizing drugs alter the receptors so that they cannot respond to endogenous ACH stimulation.

Question 17

The discontinuation of intrathecal baclofen therapy should be gradual in order to prevent:

A) severe hypotension.
B) hyperglycemia.
C) rebound spasticity.
D) hypernatremia.

Question 18

Which of the following should be taken into consideration when selecting a neuromuscular blocking drug for surgical relaxation?

A) Duration of action
B) Time of onset
C) Reversibility of the drug
D) All of these

Question 19

Which centrally acting skeletal muscle relaxant can lead to dependency upon prolonged use?

A) Baclofen
B) Methocarbamol
C) Diazepam
D) Orphenadrine

Question 20

Which factor is most likely responsible for the variation of duration of action in nondepolarizing skeletal muscle relaxants?

A) Drug excretion
B) Drug metabolism
C) Drug absorption
D) Drug distribution

Question 21

Which of the following spasmolytics is primarily used as a tranquilizer?

A) Succinylcholine
B) Pancuronium bromide
C) Dantrolene
D) Diazepam

Question 22

Identify an accurate statement about nondepolarizing blockers.

A) Nondepolarizing blockers do not stimulate the nicotinic-muscle (Nm) receptors.
B) Nondepolarizing blockers occupy the nicotinic-neural (Nn) sites and prevent acetylcholine (ACH) from combining with the Nn receptors.
C) Nondepolarizing drugs are metabolized much faster than depolarizing drugs.
D) Nondepolarizing blockers alter the Nm receptors so that they cannot respond to ACH stimulation.

Question 23

Which of the following statements is true of the mechanism of action of direct-acting skeletal muscle relaxants?

A) Direct-acting skeletal muscle relaxants facilitate skeletal muscle fiber contraction.
B) Direct-acting skeletal muscle relaxants interact with special receptors in the sarcoplasmic reticulum to block the release of calcium ions.
C) Direct-acting skeletal muscle relaxants directly affect the nicotinic-muscle receptors.
D) Direct-acting skeletal muscle relaxants act within the central nervous system to produce skeletal muscle relaxation.

Question 24

Which of the following statements is true of how the drug neostigmine helps in the treatment of skeletal muscle paralysis caused by nondepolarizing blockers?

A) It enhances the activity of the enzyme acetylcholinesterase to prevent acetylcholine (ACH) from accumulating within the synaptic cleft.
B) It modifies the nicotinic-muscle (Nm) receptors so that ACH cannot produce its effect.
C) It directly stimulates the Nm receptors to induce depolarization.
D) It triggers a series of changes that lead to muscular relaxation.

Question 25

_____ is the principal inhibitory neurotransmitter within the brain.

A) Serotonin
B) Dopamine
C) Acetylcholine
D) Gamma-aminobutyric acid (GABA)

Question 26

Which of the following statements is true of centrally acting skeletal muscle relaxants?

A) They inhibit or interrupt painful intermittent muscle contractions.
B) They boost reflex impulse conduction within the spinal cord.
C) They lead to an increase in the number of impulses available to produce muscle contraction.
D) They alter the function of the nicotinic-muscle receptors or the skeletal muscle fibers.

Question 27

Some patients may have a genetic predisposition to developing malignant hyperthermia when taking an inhalation anesthetic with _____.

A) pancuronium
B) succinylcholine
C) dantrolene
D) baclofen

Question 28

Which muscle relaxant would be used in the treatment of a patient with a spinal cord injury?

A) Succinylcholine
B) Dantrolene
C) Baclofen
D) Mivacurium

Question 29

What is the drug of choice for treating malignant hyperthermia?

A) Tizanidine
B) Dantrolene
C) Baclofen
D) Diazepam

Question 30

Ally,a health care professional,is discussing the use of the botulinumtoxin for cosmetic purposes with her friend,Jennifer.When Jennifer asks Ally for her advice on undergoing Botox therapy,which of the following points will Ally most likely state?

A) Using botulinum toxin is very safe and has no adverse side effects.
B) People with respiratory problems cannot undergo Botox therapy.
C) The botulinum toxin does not spread to other areas of the body from the site of injection.
D) People who are hypersensitive to human albumin should not undergo Botox therapy.

Question 31

A patient with breathing problems is given a muscle relaxant.As soon as he starts taking the drug,he begins to experience bronchospasms,a symptom that may eventually lead to an asthmatic attack.This can be attributed to the release of:

A) acetylcholine.
B) norepinephrine.
C) serotonin.
D) histamine.

Question 32

Why is the drug dantrolene considered a direct-acting peripheral skeletal muscle relaxant?

A) Because it inhibits the release of calcium ions within the muscle fiber
B) Because it allows actin and myosin to interact with each other
C) Because it affects the nicotinic-muscle receptors and the neuromuscular junction
D) Because it does not affect the ryanodine receptor channel

Question 33

_____ ions are the most critical for muscle contraction because they interact with the contractile filaments.

A) Magnesium
B) Zinc
C) Calcium
D) Phosphate

Question 34

Skeletal muscle relaxation is desirable in diseases such as _____.

A) cerebral palsy
B) glaucoma
C) Alzheimer's disease
D) urinary retention

Question 35

Which of the following types of medicines can potentiate the effects of succinylcholine due to shifting of the levels of potassium in the body?

A) Narcotics
B) NSAIDs
C) Antiemetics
D) Diuretics