CAPS 391 Study Guide - Lifting Bag, Phosphocreatine, Glycogen
17 Feb 2013
School
Course
Professor
Document Summary
Aps carried by motor neurons cause aps to be produced in muscle fibers based on events of nmj. Axons of motor neurons carry aps from brain/spinal cord to skeletal muscle fibers, branch each to one muscle fiber to innervate. Near muscle fiber, axon branch forms cluster of enlarged terminals that rest in invagination of sarcolemma to form nmj (synapse) > axon terminals/area of muscle fiber sarcolemma they innervate. Muscle plasma membrane in the area of the junction > postsynaptic membrane (motor-end-plate). Presynaptic terminal > mitochondria, small spherical sacs (synaptic vesicles). Synaptic vesicles > contain acetylcholine, organic molecule of acetic acid + choline (neurotransmitter). Neurotransmitter > substance released from presynaptic membrane, diffuses across synaptic cleft, alters activity of postsynaptic cell. Stimulate or inhibit ap in postsynaptic membrane by binding to ligand gated channels. When ap reaches presynaptic terminal, voltage gated ca+ channels open and ca diffuses into cell.
