Anatomy (CNS) · MU Sofia

148. White substance of spinal cord. Roots. Propriospinal tracts.

Covers the white matter of the spinal cord, explaining how its myelinated tracts are arranged into ascending and descending columns, with the lateral, posterior and anterior columns and the main tracts in each listed. It then describes the dorsal and ventral roots, their sensory and motor fibres, and how they join to form spinal nerves. Grey matter laminae VIII to X are briefly noted at the start, including the motor nuclei of lamina IX.

Inside: 5 sections · 10 labelled pictures · 10 flashcards · 3 min

Topic 6 of 34 in the MU Sofia syllabus for Anatomy (CNS) (Medicine, Year 2). The free AceMed note covers it in 5 sections, about 364 words (3 min of reading), with 10 flashcards.

In this note

  1. Introduction
  2. WHITE SUBSTANCE
  3. Arrangment :
  4. Tracts :
  5. ROOTS

Introduction

7. Lamina VIII :

  • → hleps to modulate movement and muscle tone.

9. lamina X : where axons cross over from one side to another

8. Lamina IX :

  • Posterior → Supplying flexors
  • Anterior → " Extensors
  • lateral — only in Enlargments — S: Distal limbs
  • Central — S: Proximal limbs
  • Medial — S: Axiall musculator " neck + head "
  • Phrenic (C3-C5) → Diaphragm
  • Accessory spinal (C1- C6) → Sternocledio mastoid → Trapezius
  • Onufs nucleus (S2 -S4) ↳ sphincter (external)

WHITE SUBSTANCE

  • White matter - Contains tracts of myelinated axons with supporting cells (myelinated ↓ contains white lipids.)
  • Function: Enable communication between the spinal cord and higher levels of the CNS.

Forms a system of Ascending , Descending and Associative tracts

* tracts - Bundle of Axons In CNS.

Arrangment :

  • White matter arranged into columns :

Each column contains spesific tracts (Ascending ↓ Sensory & Descending ↓ Motor) with specific functions.

Tracts :

→ Lateral column: → Somatotopic arrangment

  1. 1. Lateral Corticospinal tract. ↳ Responsible for voluntary motor control
  2. 2. Rubrospinal tract - responsible in motor coordination

Descending ↓ motor

  1. 3. Dorsal spinocerebral tract
  2. 4. Ventral spinocerebral tract
  3. 5. Lateral spinothalmic tract
  4. 6. Spinolivary tract

Ascending ↑

→ Posterior column : "transmit sensory info. from the Peripheral nerves to the brain"

  1. 1. Fasciculus Gracilis - Caries signals from the lower body.
  2. 2. Fasciculus Cuneatus - Caries signals from the upper body

Asc. ↑↑

→ Anterior column

  1. 1. Lateral reticulospinal track.
  2. 2. Medial " "
  3. 3. Vestibulo spinal tract.
  4. 4. Tectospinal "
  5. 5. Ant. corticospinal " (cortex)

Desc. ↓

  1. 6. Ant. Spinothalmic tract ] Ascending ↑ " sensory "

148 cont.

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