the mark in a contraction is called apostrophe.
the mark in a contraction is called apostrophe.
what is the mark in a contraction called?
apostrophe
Na
Na
neuromuscular junctions are the focal point where a motor neuron attaches to a muscle. acetylcholine, (a neurotransmitter used in skeletal muscle contraction) is released from the axon terminal of the nerve cell when an action potential reaches the microscopic junction called a synapse. a group of chemical messengers cross the synapse and stimulate the formation of electrical changes, which are produced in the muscle cell when the acetylcholine binds to receptors on its surface. calcium is released from its storage area in the cell's sarcoplasmic reticulum. an impulse from a nerve cell causes calcium release and brings about a single, short muscle contraction called a muscle twitch. if there is a problem at the neuromuscular junction, a very prolonged contraction may occur, such as the muscle contractions that result from tetanus. also, a loss of function at the junction can produce paralysis.
muscular system