Glossary of Physiology Terms – M
In striated muscle sarcomere, the M line is the attachment site for the thick filaments. The M line is in the center of the A band
and, thus, it is in the center of the sarcomere.
Related glossary terms/phrases:A bandH zoneI bandZ disk
The voltage difference across a cell plasma membrane.
The membrane potential is generally inside negative with respect to the outside, where the outside potential is generally set as the reference value. In electrically excitable cells, the value of the membrane potential can be positive (inside with respect to the outside) during electrical activity (i.e., during action potentials).
Related glossary terms/phrases:Resting membrane potential
See also:Resting membrane potential
A motor unit is composed of a motor neuron and all of the muscle fibers (i.e., muscle cells) it innervates.
Alternatively, a motor unit is a group of muscle fibers innervated by a single motor neuron.
Chemical warfare agent belonging to sulfur (or sulphur) mustards. Causes severe chemical burns and water blisters (i.e., it is a vesicant). It is cytotoxic, mutagenic, and carcinogenic.
Other resources:Sulfur mustard (Wikipedia)
Plasma membrane of a muscle cell. It is also referred to as sarcolemma
Related glossary terms/phrases:Sarcolemma
Cytoplasm of a muscle cell. It is also referred to as sarcoplasm
Related glossary terms/phrases:Sarcoplasm
A condition associated with hypothyroidism (especially primary hypothyroidism) in adults. It is characterized by thick, course skin, skin swelling (edema), and decreased metabolic rate and mental activity.
Posted: Wednesday, March 6, 2013
Last updated: Thursday, February 11, 2016