rubrospinal tract
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The rubrospinal tract is a part of the
nervous system In biology, the nervous system is the highly complex part of an animal that coordinates its actions and sensory information by transmitting signals to and from different parts of its body. The nervous system detects environmental changes ...
. It is a part of the
lateral Lateral is a geometric term of location which may refer to: Healthcare *Lateral (anatomy), an anatomical direction * Lateral cricoarytenoid muscle * Lateral release (surgery), a surgical procedure on the side of a kneecap Phonetics *Lateral co ...
indirect extra-pyramidal tract.


Structure

In the
midbrain The midbrain or mesencephalon is the forward-most portion of the brainstem and is associated with vision, hearing, motor control, sleep and wakefulness, arousal (alertness), and temperature regulation. The name comes from the Greek ''mesos'', " ...
, it originates in the magnocellular red nucleus, crosses to the other side of the midbrain, and descends in the lateral part of the brainstem
tegmentum The tegmentum (from Latin for "covering") is a general area within the brainstem. The tegmentum is the ventral part of the midbrain and the tectum is the dorsal part of the midbrain. It is located between the ventricular system and distinctive ba ...
. In the
spinal cord The spinal cord is a long, thin, tubular structure made up of nervous tissue, which extends from the medulla oblongata in the brainstem to the lumbar region of the vertebral column (backbone). The backbone encloses the central canal of the sp ...
, it travels through the
lateral funiculus The most lateral of the bundles of the anterior nerve roots is generally taken as a dividing line that separates the anterolateral system The spinothalamic tract is a part of the anterolateral system or the ventrolateral system, a sensory path ...
of the spinal cord, coursing adjacent to the
lateral corticospinal tract The lateral corticospinal tract (also called the crossed pyramidal tract or lateral cerebrospinal fasciculus) is the largest part of the corticospinal tract. It extends throughout the entire length of the spinal cord, and on transverse section appe ...
.


Function

In humans, the rubrospinal tract is one of several major motor control pathways. It is smaller and has fewer axons than the
corticospinal tract The corticospinal tract is a white matter motor pathway starting at the cerebral cortex that terminates on lower motor neurons and interneurons in the spinal cord, controlling movements of the limbs and trunk. There are more than one million neur ...
, suggesting that it is less important in motor control. It is one of the pathways for the mediation of involuntary movement, along with other extra-pyramidal tracts including the vestibulospinal, tectospinal, and reticulospinal tracts. The tract is responsible for large muscle movement regulation flexor and inhibiting extensor tone as well as fine motor control. It terminates primarily in the cervical and thoracic portions of the spinal cord, suggesting that it functions in upper limb but not in lower limb control. It is small and rudimentary in
humans Humans (''Homo sapiens'') are the most abundant and widespread species of primate, characterized by bipedalism and exceptional cognitive skills due to a large and complex brain. This has enabled the development of advanced tools, culture, ...
. In some other primates, however, experiments have shown that over time, the rubrospinal tract can assume almost all the duties of the
corticospinal tract The corticospinal tract is a white matter motor pathway starting at the cerebral cortex that terminates on lower motor neurons and interneurons in the spinal cord, controlling movements of the limbs and trunk. There are more than one million neur ...
when the corticospinal tract is lesioned.


See also

*
Upper motor neuron Upper motor neurons (UMNs) is a term introduced by William Gowers in 1886. They are found in the cerebral cortex and brainstem and carry information down to activate interneurons and lower motor neurons, which in turn directly signal muscles t ...


References


External links

* {{DEFAULTSORT:Rubrospinal Tract Spinal cord tracts Motor system