Pathways of Spinal Cord and Brain

Naming of neural pathways A neural pathway is a neural tract connecting one part of the nervous system with another, usually consisting of bundles of elongated, myelin insultated neurons, known collectively as white matter. Neural pathways serve to connect relatively distant areas of the brain or nervous system, compared to the local communication of grey matter. Naming of neural pathways The first named pathways were evident even in a poorly-preserved gross brain, and were named by the great anatomists of the Renaissance using cadaver material. Examples of these include the great commissures of the brain such as the corpus callosum (Latin, "huge body"), anterior commissure or posterior commissure.

Hindbrain Medulla Pons Cerebellum Pons Medulla Cerebellum http://www-unix.oit.umass.edu/~psyc335c/lectures/hindbrain.gif

Hindbrain Medulla Pons Cerebellum Pons Medulla Cerebellum http://www-unix.oit.umass.edu/~psyc335c/lectures/hindbrain.gif

The Spinothalamic Tract is a sensory pathway originates in the spinal cord that transmits information about pain, temperature, itch and crude touch to the thalamus.

M L PN S G E

G S S G E

The Lateral spinothalamic tract transmits pain and temperature. The Anterior spinothalamic tract transmits touch.

S G P

N R P S G D N Spino cerebellar tracts anterior posterior

Hindbrain Medulla Pons Cerebellum Pons Medulla Cerebellum http://www-unix.oit.umass.edu/~psyc335c/lectures/hindbrain.gif

N R N R P S G D N

The Rubrospinal tract arises from the large cells of the red nucleus   The Rubrospinal tract arises from the large cells of the red nucleus. The fibers cross the raphé of the mid-brain in the decussation of Forel and descend in the formatio reticularis of the pons and medulla dorsal to the medial lemniscus and as they pass into the spinal cord come to lie in a position ventral to the crossed pyramidal tracts in the lateral funiculus.

R T c v C(p) N p th I-m I-lat

The corticospinal tract mostly contains motor axons The corticospinal tract mostly contains motor axons. It actually consists of two separate tracts in the spinal cord: the lateral corticospinal tract and the medial corticospinal tract. An understanding of these tracts leads to an understanding of why for the most part, one side of the body is controlled by the opposite side of the brain.

R T c v C(p) N p th I-m I-lat

Second neurons of cortico-nuclear tract pass through cranial nerves

III IV Cortico- Nuclear tract V VII VI IX X XII XI

Cortico- Ponto- Cerebellar tract PONS