Muscles - Medical Terminology(Adaptive*)

Types of Muscle Fibers

There are three types of muscular fibers or tissue:

  • Skeletal muscle fibers are composed of striations that move bones of the skeleton and work mainly in a voluntary manner. Muscle fibers contract in response to stimulation and then relax when the stimulation ends. Their activity can be consciously controlled by neurons that are part of the somatic (voluntary) division of the nervous system. To some extent, skeletal muscles are also controlled subconsciously.
    For example, the diaphragm continues to alternately contract and relax without conscious control so that breathing does not stop.
  • Cardiac muscle fibers, also composed of striations, are found only in the heart and form most of the heart wall. The alternating contraction and relaxation of the heart is involuntary and is not consciously controlled. Rather, the heart beats because it has a pacemaker that initiates each contraction.
    This built-in rhythm is called autorhythmicity. Several hormones and neurotransmitters can adjust heart rate by speeding or slowing the pacemaker.
  • Smooth muscle fibers are shorter and lack the striations of skeletal and cardiac muscle tissue. For this reason, it has a smooth appearance, which gives it its name. The action of smooth muscle is usually involuntary and some smooth muscle tissue, such as the muscles that propel food through the gastrointestinal tract, has autorhythmicity. Smooth muscle and cardiac muscle are regulated by neurons that are part of the autonomic (involuntary) division of the nervous system and hormones released by endocrine glands.

Fibers within each muscle are characteristically arranged into specific patterns that provide specific functional capabilities. Most skeletal muscles lie between the skin and the skeleton.

Body-movements-generated-by-muscles

Body movements generated by muscles

Sports-related injuries are commonly caused by the tremendous stress exerted on certain parts of musculoskeletal structures. In many instances, these types of athletic injuries may result in a torn muscle.Form a word that means rupture (tear) of a muscle.

Body movements generated by muscles


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