HI310 Lecture Notes - Lecture 4: Neuromuscular Junction, Skeletal Muscle, Myocyte
24 Jan 2019
Department
Course
Professor
Document Summary
What is a neuromuscular junction: smooth, cardiac, skeletal. Makes up the walls of hollow body organs, blood vessels, and respiratory passageways. Produces wavelike motions that move substances through a system. Controls diameter of openings like blood vessels, causes contractions. React because of nerve impulse, hormonal stimulation, stretching, etc. Makes up the wall of the heart. Creates a pulsing action one nucleus per cell, branching interconnections. Intercalated discs special membranes for electrical impulses that are inserted between cells. Muscles are attached to bones to produce movement in joints: exceptions: abdominal, facial. 40% of body weight: movement, posture (muscle tone, heat generation. A steady partial contraction of muscle, known as muscle tone, keeps the body in position. Endomysium around each individual muscle fiber. Perimysium around fascicles (bundles) of muscle fibers. Epimysium around entire muscle; forms the innermost layer of the deep fascia. A single neuron and all the muscle fibers it stimulates comprise a motor unit.
