Exam 3 Review:  Chapter 09:  General Muscle Terminology

myology - The scientific study of muscle anatomy and physiology.

voluntary muscle tissue - The muscle tissue, usually striated skeletal muscle, which can be controlled (contracted) consciously by motor commands from the cerebral cortex, even though some control is maintained by lower centers in the CNS = Central Nervous System.

involuntary muscle tissue - A muscle that contracts without conscious control; includes smooth muscle  found in walls of internal organs such as the stomach and intestines and bladder and blood vessels as well as cardiac muscle in the heart; a few skeletal muscles also operate under involuntary control, such as the muscles for breathing and swallowing, however, those skeletal muscles are subject to conscious control as well.

striated muscle tissue - The muscle tissue characterized by transverse stripes, a banding pattern observed in microscopy, due to the parallel arrangement of the contractile proteins, actin and myosin, within the cell's contractile organelles, the myofibrils, which are comprised of repeating functional units, the sarcomeres; skeletal and cardiac muscle are striated.

nonstriated muscle tissue = smooth muscle tissue - The muscle tissue characterized by the absence of transverse stripes or a banding pattern observed in microscopy, due to the diffuse network arrangement of the contractile proteins, actin and myosin, which are not organized into myofibrils; the cytoplasm also lacks the T tubule system and the connective tissue around this muscle tissue never unites to form tendons or aponeuroses; the spindle-shaped, uninucleate, involuntary contractile cells controlled by the autonomic nervous system; it may be autorhythmic; it is the muscle type found in the walls of tubular internal organs, in the iris of the eye, in the arrector pili muscles, uterus, etc.

skeletal muscle tissue - A usually voluntary striated muscle made up of elongated, multinucleated, transversely striated muscle fibers, having principally attachments to bones.

satellite cell - A low frequency (<1%) striated muscle tissue cell (discovered in 1961) which is an undifferentiated stem cell (myoblast) which is dormant in healthy muscle tissue but can help repair damage by dividing and migrating to an injured area of the muscle; satellite cells are decreased in number with increased age or with certain diseases such as duchenne muscular dystrophy.  [Note:  there is also a different "satellite cell" identified in peripheral nervous tissue.  satellite cell - any of the glial cells that encapsulate and provide protection and support for the cell bodies of peripheral neurons in the many peripheral ganglia.]

List:

1. Three types of muscle tissue and describe the appearance, location and physiological properties of each.