Lably
Skip to content

Projection fiber

Consist of efferent and afferent fibers uniting the cortex

  • 1 min read
  • 2 chapters

Related on Lably

Through Spinal cord

Lab · Class 10–11Neural ControlLab · Class 10–11Inside the BrainLab · Class 11Neural Control and Coordination — Animated Chapter FilmLab · Class 11One Day Inside the Human Body — Animated Chapter Film

In the neocortex, projection neurons are excitatory neurons that send axons to distant brain targets. Considering the six histologically distinct layers of the neocortex, associative projection neurons extend axons within one cortical hemisphere; commissural projection neurons extend axons across the midline to the contralateral hemisphere; and corticofugal projection neurons extend axons away from the cortex. That said, some neurons are multi-functional and can therefore be categorized into more than one such category.

Efferent

The principal efferent fibers are:

  1. the motor tract, occupying the genu and anterior two-thirds of the occipital part of the internal capsule, and consisting of
    1. the geniculate fibers, which decussate in the medulla, and end in the motor nuclei of the cranial nerves of the opposite side; and
    2. the cerebrospinal fibers, which are prolonged through the medullary pyramids into the spinal cord
  2. the corticopontine fibers, ending in the pontine nuclei.

Sign in to keep reading

One more chapter is free with a Lably account.

More in Human body

Anatomical terms of locationStandard terms for unambiguous description of relative placement of body partsPrefrontal cortexPart of the brain responsible for personality, decision-making, and social behaviorPubMedOnline biomedical databaseMucous membraneProtective layer that lines the interior of hollow organsNeuroimagingSet of techniques to measure and visualize aspects of the nervous systemNeuroscientistIndividual who studies neuroscience