A cataract is a clouding of the lens in the eye that affects vision. Most cataracts are related to aging. Cataracts are very common in older people. By age 80, more than half of all Americans either have a cataract or have had cataract surgery.
Acetylcholine. Acetylcholine (ACh) is the transmitter released by the preganglionic nerve terminals of both the sympathetic and the parasympathetic divisions (Fig 6.2). The synapse at those sites utilizes a nicotinic receptor similar in structure to the receptor at the neuromuscular junction.
Acetylcholine is a neurotransmitter that is released in the synaptic cleft and goes over the sarcolemma down the tubule and promotes the release of calcium from the sarcoreticulum which then binds to proteins on actin which exposes binding spots for myosin to attach to and powerstroke causing muscle contraction.he result of this binding of acetylcholine to the acetylcholine receptor is opening of sodium channels and influx of sodium cations into the muscle cell, causing the resting potential of that muscle cell to begin to depolarize.