Spinal Cord Medical Neuroscience Dr Wiegand Directions dorsal

Spinal Cord Medical Neuroscience Dr. Wiegand

Directions dorsal rostral ventral caudal

Terms rostral - toward the “beak” ¢ caudal - toward the “tail” ¢ ventral - toward the front (anterior) ¢ dorsal - toward the back (posterior) ¢ superior - above ¢ inferior - below ¢

Spinal Cord ¢ Central gray nuclei and outer white matter (tracts) Descending Cell bodies tracts Peripheral nerve fibers Ascending tracts

Peripheral and Central Nervous System PNS sensory motor Lesions CNS

Spinal nerves & cord ¢ ¢ 31 pairs with anterior and posterior root C 1 often doesn’t have posterior root Spinal cord enlarged in C 5 – T 1 and L 2 – S 3 levels Spinal cord ends at L 1 vertebral level

Dermatomes & Myotomes ¢ ¢ Dermatome – an area of skin innervated by a single posterior root Myotome – a group of muscles innervated by a single anterior root

C 4 T 10 L 3 Dermatomes L 5 Myotomes

Stretch Reflexes ¢ Examples: C 5 -6 = biceps tendon l C 6 = brachioradialis l C 7 -8 = triceps tendon l L 2 -4 = patellar tendon l S 1 -2 = Achilles tendon l

External Spinal Cord Conus medullaris Filum terminale Cauda equina Dura mater

External Structure – Spinal Cord Posterior Median Sulcus Lateral sulci Posterior Intermediate Sulci Anterior Median Fissure

Internal Structure – White Matter Posterior Funiculi Lateral Anterior

White Matter Organization: Ascending Pathways f. gracilis tus nea f. cu Lateral & Anterior Spinothalamic Tracts Posterior Columns Posterior & Anterior Spinocerebellar Tracts

White Matter Organization: Descending Pathways Lateral Corticospinal Tract Anterior Corticospinal Tract Rubrospinal Tract Reticulospinal Tracts Vestibulospinal Tracts

White Matter Organization: Intersegmental Pathways Lissauer’s Tract Intersegmental Tracts

White Matter Organization: Ascending Pathways Posterior Columns LTA Lateral & Anterior Spinothalamic Tracts L N N

White Matter Organization: Descending Pathways Legs T A Neck

Grey Matter Organization Posterior Motor Groups Intermediate Anterior Lateral Medial

Grey Matter Organization: Anterior Cell Columns

Grey Matter Organization: Lateral Grey Horns: T 1 – L 2/3 AKA Intermediolateral Cell Column

Grey Matter Organization: Posterior Cell Column Dorsomarginal nucleus Substantia gelatinosa Nucleus proprius Nucleus dorsalis (Clarke’s column)

From Pritchard & Alloway: Fig. 3 -7

http: //lansing. bellarmine. edu/ pt/atlas/cover. html

Rexed Lamina Dorsomarginal n. Substantia gelatinosa Nucleus proprius Nucleus dorsalis (Clarke’s column) Motor nuclei

Brown-Sequard Syndrome