BSC 469 Lecture Notes - Lecture 10: Choline, Muscle Tone, Autoimmune Disease

• School: University of Alabama
• Department: Biological Sciences
• Course: BSC 469
• Professor: Rasco

Document Summary

Troponin: complex of 3 polypeptides, tni binds to actin, tnt binds to tropomyosin, tnc binds to ca++ Microscopic anatomy of a muscle: myofibrils aligned across width of a cell so appears striated, sarcomere functional contractile unit of skeletal muscle. Muscle innervation: muscles are stimulated by motor neurons, motor neurons secrete acetylcholine, a neurotransmitter. Sarcomere: a sarcomere is the contractile unit of skeletal muscle, the biceps contain over 100,000 sarcomeres arranged end-to-end, a sarcomere from z line to z line. Phases of muscle contraction and relaxation: phase i excitation, phase ii excitation-contraction coupling, phase iii contraction, phase iv relaxation. Muscle contraction: skeletal muscle cells are stimulated by motor neurons, the axon of each motor neuron branches when it enters the muscle, most of the time there is one neuromuscular junction for each muscle fiber. Excitable cells: excitable cells are those that can be stimulated to create a tiny electric current.