The upper part of the posterior district of the
medulla oblongata
The medulla oblongata or simply medulla is a long stem-like structure which makes up the lower part of the brainstem. It is anterior and partially inferior to the cerebellum. It is a cone-shaped neuronal mass responsible for autonomic (involun ...
is occupied by the inferior cerebellar peduncle, a thick rope-like strand situated between the lower part of the
fourth ventricle and the roots of the
glossopharyngeal and
vagus nerves.
Each cerebellar inferior peduncle connects the
spinal cord and medulla oblongata with the
cerebellum
The cerebellum (Latin for "little brain") is a major feature of the hindbrain of all vertebrates. Although usually smaller than the cerebrum, in some animals such as the mormyrid fishes it may be as large as or even larger. In humans, the cerebel ...
, and comprises the
juxtarestiform body and restiform body.
Important fibers running through the inferior cerebellar peduncle include the
dorsal spinocerebellar tract and axons from the
inferior olivary nucleus, among others.
Function
The inferior cerebellar peduncle carries many types of input and output fibers that are mainly concerned with integrating
proprioceptive sensory input with motor vestibular functions such as
balance and
posture maintenance. It consists of the following fiber tracts entering cerebellum:
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Posterior spinocerebellar tract
The spinocerebellar tract is a nerve tract originating in the spinal cord and terminating in the same side (ipsilateral) of the cerebellum.
Origins of proprioceptive information
Proprioceptive information is obtained by Golgi tendon organs and ...
: unconscious
proprioceptive information from the lower part of trunk and lower limb. This tract originates at the ipsilateral
Clarke's nucleus (T1-L1) and travels upward to reach the inferior cerebellar peduncle and synapses within the
spinocerebellum
The anatomy of the cerebellum can be viewed at three levels. At the level of gross anatomy, the cerebellum consists of a tightly folded and crumpled layer of cortex, with white matter underneath, several deep nuclei embedded in the white matte ...
(also known as the paleocerebellum).
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Cuneocerebellar tract: unconscious proprioceptive information from the upper limb and neck. This tract originates at the ipsilateral accessory cuneate nucleus and travels through the inferior cerebellar peduncle to reach the spinocerebellum part of the cerebellum.
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Trigeminocerebellar tract: unconscious proprioceptive information from the face.
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Olivocerebellar tract: "error signal" in movement originates from the cerebral cortex and spinal cord. This tract originates at contralateral inferior olivary nucleus and enters the cerebellum as a
climbing fiber.
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Vestibulocerebellar tract: vestibular information projects onto the
vestibulocerebellum
The anatomy of the cerebellum can be viewed at three levels. At the level of gross anatomy, the cerebellum consists of a tightly folded and crumpled layer of cortex, with white matter underneath, several deep nuclei embedded in the white matte ...
(also known as the archicerebellum).
This peduncle also carries information leaving cerebellum: from the
Purkinje cells to the vestibular nuclei in the dorsal
brainstem
The brainstem (or brain stem) is the posterior stalk-like part of the brain that connects the cerebrum with the spinal cord. In the human brain the brainstem is composed of the midbrain, the pons, and the medulla oblongata. The midbrain is cont ...
located at the junction between the
pons and
medulla oblongata
The medulla oblongata or simply medulla is a long stem-like structure which makes up the lower part of the brainstem. It is anterior and partially inferior to the cerebellum. It is a cone-shaped neuronal mass responsible for autonomic (involun ...
.
See also
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Cerebral peduncle
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Juxtarestiform body
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Middle cerebellar peduncles
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Superior cerebellar peduncles
Additional images
File:Gray691.png, Dissection of brain-stem. Dorsal view.
File:Gray699.png, Diagram showing the course of the arcuate fibers.
File:Lower pons horizontal KB.svg, Cross section of lower pons showing part of the inferior cerebellar peduncle (#8) labeled at the upper left.
File:Slide2SEER.JPG, Cerebellum. Inferior surface.
References
External links
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{{DEFAULTSORT:Inferior Cerebellar Peduncle
Brainstem
Cerebellar connections