Projection fiber

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The projection fibers consist of efferent and afferent fibers uniting the cortex with the lower parts of the brain and with the spinal cord.

Efferent

The principal efferent strands are:

(1) the motor tract, occupying the genu and anterior two-thirds of the occipital part of the internal capsule, and consisting of
- (a) the geniculate fibers, which decussate and end in the motor nuclei of the cranial nerves of the opposite side; and
- (b) the cerebrospinal fibers, which are prolonged through the pyramid of the medulla oblongata into the medulla spinalis:
(2) the corticopontine fibers, ending in the nuclei pontis.

The chief afferent fibers are:

(1) those of the lemniscus which are not interrupted in the thalamus;
(2) those of the superior cerebellar peduncle which are not interrupted in the red nucleus and thalamus;
(3) numerous fibers arising within the thalamus, and passing through its stalks to the different parts of the cortex ;
(4) optic and acoustic fibers, the former passing to the occipital, the latter to the temporal lobe.

This article incorporates text from a public domain edition of Gray's Anatomy.

General

insulating:	Myelination: Oligodendrocyte

other	Astrocyte Radial glial cell Ependymal cells Tanycyte Microglia

Other

General	Posterior Root Ganglion Ramus Anterior Root Ramus Ramus communicans Gray White Autonomic ganglion (Preganglionic nerve fibers Postganglionic nerve fibers)

Connective tissues	epineurium perineurium endoneurium nerve fascicle

Neuroglia	Myelination: Schwann cell Neurolemma Myelin incisure Myelin sheath gap Internodal segment Satellite glial cell

Parts

Perikaryon	Axon hillock

Axon	Axon terminals Axoplasm Axolemma Neurofibril/neurofilament

Dendrite	Nissl body Dendritic spine Apical dendrite/Basal dendrite

Types

Termination

Synapse	Electrical synapse/Gap junction Chemical synapse Synaptic vesicle Active zone Postsynaptic density Ribbon synapse Neuromuscular junction

Sensory receptors	Meissner's corpuscle Merkel nerve ending Pacinian corpuscle Ruffini ending Muscle spindle Free nerve ending Olfactory receptor neuron Photoreceptor cell Hair cell Taste bud

anat (n/s/m/p/4/e/b/d/c/a/f/l/g)/phys/devp

noco (m/d/e/h/v/s)/cong/tumr, sysi/epon, injr

proc, drug (N1A/2AB/C/3/4/7A/B/C/D)

anat (h/r/t/c/b/l/s/a)/phys (r)/devp/prot/nttr/nttm/ntrp

noco/auto/cong/tumr, sysi/epon, injr

proc, drug (N1B)

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