In humans, the tectospinal tract (or colliculospinal tract) is a
nerve tract
A nerve tract is a bundle of nerve fibers (axons) connecting nuclei of the central nervous system. In the peripheral nervous system this is known as a nerve, and has associated connective tissue. The main nerve tracts in the central nervous syste ...
that coordinates head and eye movements. This tract is part of the
extrapyramidal system and connects the
midbrain tectum
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'', "m ...
, and
cervical regions of 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 spin ...
.
It is responsible for motor impulses that arise from one side of the midbrain to muscles on the opposite side of the body (contralateral). The function of the tectospinal tract is to mediate reflex postural movements of the head in response to visual and auditory stimuli.
The portion of the midbrain from where this tract originates is the
superior colliculus
In neuroanatomy, the superior colliculus () is a structure lying on the roof of the mammalian midbrain. In non-mammalian vertebrates, the homologous structure is known as the optic tectum, or optic lobe. The adjective form '' tectal'' is commo ...
, which receives afferents from the visual nuclei (primarily the
oculomotor nuclei complex
The fibers of the oculomotor nerve arise from a nucleus in the midbrain, which lies in the gray substance of the floor of the cerebral aqueduct and extends in front of the aqueduct for a short distance into the floor of the third ventricle. From t ...
), then projects to the
contralateral
Standard anatomical terms of location are used to unambiguously describe the anatomy of animals, including humans. The terms, typically derived from Latin or Greek roots, describe something in its standard anatomical position. This position prov ...
(decussating dorsal to the mesencephalic duct) and ipsilateral portion of the first cervical
neuromeres of 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 spin ...
, the oculomotor and trochlear nuclei in the midbrain and the abducens nucleus in the caudal portion of the pons.
The tract descends to the
cervical spinal cord to terminate in
Rexed laminae VI, VII, and VIII to coordinate
head
A head is the part of an organism which usually includes the ears, brain, forehead, cheeks, chin, eyes, nose, and mouth, each of which aid in various sensory functions such as sight, hearing, smell, and taste. Some very simple animals may no ...
,
neck
The neck is the part of the body on many vertebrates that connects the head with the torso. The neck supports the weight of the head and protects the nerves that carry sensory and motor information from the brain down to the rest of the body. In ...
, and
eye
Eyes are organs of the visual system. They provide living organisms with vision, the ability to receive and process visual detail, as well as enabling several photo response functions that are independent of vision. Eyes detect light and conv ...
movements, primarily in response to visual stimuli.
See also
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Spinotectal tract
*
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 ...
References
External links
Diagram at etsu.edu
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{{Authority control
Spinal cord tracts
Motor system