Question

How would the loss of acetylcholinesterase from the motor end plate affect skeletal muscle?

It would produce muscle weakness.

It would cause spastic paralysis (muscles are contracted and unable to relax).

It would cause flaccid paralysis (muscles are relaxed and unable to contract).

It would make the muscles less excitable.

It would have little effect on skeletal muscles.

Answer 1

The loss of acetylcholinesterase from the motor end plate leads to spastic paralysis, where muscles are constantly contracted and cannot relax due to unregulated accumulation of acetylcholine.

Step-by-step explanation:

The loss of acetylcholinesterase from the motor end plate would cause spastic paralysis, a condition where muscles are contracted and unable to relax. Acetylcholinesterase is crucial for breaking down the neurotransmitter acetylcholine in the synaptic cleft, which ceases the signal for muscle contraction. Without acetylcholinesterase, acetylcholine would not be removed, leading to continuous stimulation of muscle fibers and prolonged contractions.

Substances like the nerve gas Sarin, which irreversibly inhibit acetylcholinesterase, demonstrate this effect, causing muscles to remain contracted. This contrasts with other blockades, such as the inhibition of acetylcholine release by botulinum toxin, which causes flaccid paralysis, where muscles are relaxed and unable to contract.