Neuromuscular Junction Quiz

What is the role of the neuromuscular junction?

• To transmit signals between neurons

• To communicate between a neuron and a muscle fiber

• To regulate heart contractions

• To store calcium ions

What neurotransmitter is released at the neuromuscular junction?

• Dopamine

• Serotonin

• Acetylcholine

• Glutamate

What ion is necessary for acetylcholine release at the NMJ?

• Sodium

• Potassium

• Calcium

• Magnesium

What is the effect of curare on muscles?

• Increased contraction

• Reduced relaxation

• Paralysis

• Enhanced signal transmission

What is the primary symptom of Lambert-Eaton myasthenic syndrome (LEMS)?

• Muscle weakness

• Muscle spasms

• Increased heart rate

How does curare work?

• By blocking calcium channels

• By mimicking acetylcholine

• By blocking acetylcholine receptors

• By increasing neurotransmitter release

Which of the following is a similarity between neuromuscular junctions and cholinergic synapses?

• Both use dopamine as a neurotransmitter.

• Both rely on calcium for neurotransmitter release.

• Both can be inhibitory.

• Both have a motor end plate.

What happens when acetylcholine binds to its receptors on the sarcolemma?

• Calcium is released from the sarcoplasmic reticulum.

• Sodium ions enter the muscle fiber.

• Tropomyosin shifts to expose binding sites.

• The muscle fiber contracts immediately.

What type of receptors are found in the eye, and what stimulus do they detect?

• Thermoreceptors; heat

• Chemoreceptors; chemicals

• Photoreceptors; light

• Mechanoreceptors; pressure

How do the receptors in the retina act as transducers?

• By amplifying sound waves into electrical impulses

• By converting light energy into electrical impulses