nmdcat.online
BIO NMDCAT Muscles
nmdcat.online July 28, 2026

The observed experimental result of blocking the enzyme acetylcholinesterase at a neuromuscular junction would be:

A. Immediate relaxation of the skeletal muscle fiber
B. Failure of the somatic motor neuron to release acetylcholine
C. Sustained contraction or spasms of the skeletal muscle fiber
✓
D. Decreased permeability of the sarcolemma to sodium ions

📝 Explanation

Acetylcholinesterase breaks down acetylcholine (ACh) in the synaptic cleft, allowing the muscle to relax. If blocked, ACh remains in the cleft, continuously binding to receptors and causing sustained depolarization and continuous muscle contraction (spasms/tetanus).

📖 Additional Information

  • Immediate relaxation of the skeletal muscle fiber
  • Failure of the somatic motor neuron to release acetylcholine
  • Sustained contraction or spasms of the skeletal muscle fiber
  • Decreased permeability of the sarcolemma to sodium ions

Acetylcholinesterase breaks down acetylcholine (ACh) in the synaptic cleft, allowing the muscle to relax. If blocked, ACh remains in the cleft, continuously binding to receptors and causing sustained depolarization and continuous muscle contraction (spasms/tetanus).

🔗 Share This Question

Facebook Twitter LinkedIn WhatsApp

🧭 Navigate Questions

Previous Question

Concerning the attachment of actin filaments, what is the functional equivalent of Z-lines in smooth muscle?

Next Question

During a comparative histological examination, a student misidentifies cardiac muscle as skeletal muscle. Which specific structural feature should the instructor point out to correct this misconception?

Back to All Questions

🔗 Related MCQs

Concerning the duration of muscle twitches, if a skeletal muscle twitch lasts approximately 10-100 milliseconds, what is the expected duration of a typical smooth muscle contraction?
July 28, 2026
The physiological response to hypoxia (low oxygen) differs among muscle types. Which muscle type is most susceptible to irreversible damage following a brief period of hypoxia?
July 28, 2026
A medical relevance of understanding muscle tissue differences is the development of calcium channel blockers. These drugs are primarily used to treat hypertension (high blood pressure) and angina. They exert their biological effect mainly by acting on:
July 28, 2026
During the process of cell differentiation, which muscle type loses its ability to divide and form new cells almost completely, relying solely on hypertrophy for growth?
July 28, 2026
The functional relationship between the shape of a muscle cell and its tissue type is evident when observing spindle-shaped cells. This specific morphology allows the cells to:
July 28, 2026

Categories

View all →