AP PSYCHOLOGY

Detailed explanation-1: -(C) ACh (or acetylcholine) is a neurotransmitter present in all motor neurons and it helps muscles to contract and thereby is involved in all body movements. Blocking of ACh can cause impairment in muscle control and can lead to cramps, muscle twitches, and cramps.

Detailed explanation-2: -Acetylcholine and myasthenia gravis Myasthenia gravis causes the immune system to block or destroy acetylcholine receptors. Then, the muscles do not receive the neurotransmitter and cannot function normally. Specifically, without acetylcholine, muscles cannot contract.

Detailed explanation-3: -Increased acetylcholine at nicotinic sites at the neuromuscular junction causes muscle fasciculations and flaccid paralysis due to excess acetylcholine at the neuromuscular junction. Excess acetylcholine in the brain patients may cause headache, insomnia, giddiness, confusion, and drowsiness.

Detailed explanation-4: -Botulinum neurotoxins cause paralysis by blocking acetylcholine release at neuromuscular junctions. Cholinergic systems are affected the most, but adrenergic systems may also be affected by high concentrations of toxin.

Detailed explanation-5: -In the somatic nervous system, acetylcholine is used at the neuromuscular junctions, triggering the firing of motor neurons and affecting voluntary movements.