NUR1 200 Chapter Notes - Chapter 10: Parasympathetic Nervous System, Autonomic Nervous System, Skeletal Muscle
Document Summary
Muscles that contract rapidly and fatigue quickly contain mostly white fibers. Cardiac muscle: both skeletal and smooth muscle characteristics. Has involuntary control, but are striated: primarily have one nucleus, muscle cells are connected by intercalated discs that contain gap junctions. Gross structure of myocytes: sarcomeres are attached end-to-end to form myofibrils, which are surrounded by a sarcoplasmic reticulum (sr), sr is a modified endoplasmic reticulum that contains a high concentration of. Myocytes in a parallel form a muscle: the nuclei are found at the peripheral of the cells. Each nerve terminal controls a group of myocytes, and both the nerve terminal and myocytes makes up the motor unit: depolarization triggers an action potential which spreads down the sarcolemma to the. T-tubules: t-tubules travel into the sr and ca2+ is released, calcium ions bind to a regulatory subunit in troponin which triggers a change in the tropomyosin, change in tropomyosin exposes the myosin-binding sites on the actin thin filament.
