126. Funicules of the white matter of the spinal cord · Anatomy Bones and Muscles · MU Pleven

126. Funicules of the white matter of the spinal cord.

Covers the white matter of the spinal cord, arranged into columns that carry ascending sensory and descending motor tracts. It names the tracts in each column, including the lateral corticospinal and rubrospinal tracts and the posterior fasciculi gracilis and cuneatus, and describes the dorsal and ventral roots. It then walks through the ascending pathways with their neuron orders, the spinocerebellar tracts, and the descending pyramidal and extrapyramidal tracts, with a summary table of the ascending pathways.

Inside: 12 sections · 19 labelled pictures · 1 table · 10 flashcards · 14 min

Topic 125 of 236 in the MU Pleven syllabus for Anatomy Bones and Muscles (Medicine, Year 2). The free AceMed note covers it in 12 sections, about 1,928 words (14 min of reading), with 10 flashcards.

Introduction

7. Lamina VIII :

→ helps 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 Enlargements; S: Distal limbs
Central: S: Proximal limbs
Medial: S: Axial musculature "neck + head"
Phrenic (C3-C5) → Diaphragm
Accessory spinal (C1-C6) → Sternocleido mastoid → Trapezius
Onufs nucleus (S2-S4) ↳ sphincter (external)

148 WHITE SUBSTANCE

White matter - contains tracts of myelinated axons with supporting cells (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.

Arrangement :

White matter arranged into columns :

Each column contains specific tracts (Ascending (sensory) & Descending (Motor)) with specific functions:

Tracts :

→ Lateral column: → Somatotopic arrangement

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

] Descending ↓ motor

3. Dorsal spinocerebral tract
4. Ventral spinocerebral tract
5. Lateral spinothalamic tract

6. Spinolivary tract

] Ascending ↑

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

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

] Asc. ↑↑

→ Anterior column

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

] Desc.↓

6. Ant. Spinothalamic tract ] Ascending ↑ "sensory"

148 cont.