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Glossary of Physiology Terms
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There are 3 glossary search results for:   Muscle fiber




Definition:
Leading away from a region or structure of interest.

In the nervous system, efferent fibers (i.e., neurons) transmit information from the central nervous system to peripheral effector organs (i.e., muscles or glands). Therefore, the cells bodies of efferent neurons reside within the central nervous system, whereas their axonal projections exit the central nervous system to make synaptic contact with effector organs in the periphery. Efferent neurons are also referred to as motor neurons.

In the kidneys, the efferent arteriole carries blood away from the glomerular capillaries.

Related glossary terms/phrases:
Afferent



Definition:
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.



Definition:
The Z disk (or Z line) defines the boundaries of a muscle sarcomere. Two adjacent Z disks along the myofibril mark the boundaries of a single sarcomere. The Z disks are the attachment sites for the thin filaments. Therefore, from each Z disk, thin filaments extend to two neighboring sarcomeres. When a muscle fiber contracts, the Z disks of a sarcomere move closer together (i.e., the sarcomere also shortens).

Related glossary terms/phrases:
A band
H zone
I band
M line









Posted: Sunday, March 31, 2013
Last updated: Friday, August 28, 2015