The document summarizes key details about the spinal cord. It notes that the spinal cord is a long cylindrical structure in the central nervous system that extends from the brainstem down the vertebral canal. It connects the brain to the peripheral nervous system via 31 pairs of spinal nerves. The spinal cord has enlargements in the cervical and lumbar regions to innervate the upper and lower limbs. It contains gray matter in an H-shape surrounded by three columns of white matter. The document also briefly discusses clinical conditions that can affect the spinal cord.

1. Department of Rachana Sharir
Dr Samadhan M Patil
M.D. Rachana Sharir

2. Today’s Topic
 Spinal cord

3. Introduction
 It is the long cylindrical lower part of CNS
 It is the main pathway for information connecting the brain and PNS
 It is enclosed in the three meninges and occupies upper 2/3 of vertebral
canal
 It gives rise to 31 pairs of spinal nerves
 Thus spinal cord is a major connection between body and brain

4. Features
 Length:
18 inch or 45 cm in an adult male
42 cm in adult female
 Weight: 30 gm
 Extends: From upper border of atlas vertebra to lower border of L1
 Superiorly: continuous with the medulla oblongata
 Inferiorly: terminates as conus medullaris, below the level of conus
medullaris only pia mater is continued as a thin fibrous cord, the filum
terminale

5. Cauda equina
 Dorsal and ventral nerve roots of right and left sides of L2-L5, S1-S5 and
Co1 nerves lie almost vertically around filum terminale. These are called
cauda equina.
 These resemble a horse’s tail
 There are 40 nerve roots at the beginning of cauda equina

6. Enlargement
Spinal cord is not unique in its width. It shows some enlargements as:
1. Cervical enlargement:
 For supply of upper limb muscles
 Extends from C4 to T1 spinal segments
 Maximum diameter: 38 mm (at the level of C6 segment)
2. Lumber enlargement:
 For supply of lower limb muscles
 Extends from L2 to S3 spinal segments
 Maximum diameter: 35 mm ( at the level of S1 segment)

7. External features
 Two fissure
1. Anterior median fissure
2. Posterior median fissure
 Two halves
1. Right half
2. Left half
 Two sulci
1. Anterolateral sulci
2. Postero-lateral sulci
 Three regions on each half
1. Anterior region
2. Lateral region
3. Posterior region

8. Internal features
Cross section of spinal cord shows:
 Three columns of white matter (Outside)
 H shaped gray matter (Inner side)
 Central canal:
 Exactly in middle there is a hollow cavity called as central canal.
 It contains CSF
 Opens above in 4th ventricle

9.  White matter: Subdivided in 3 region
1. Anterior funiculus/ white column:
 It is present between antero-median fissure and the anterior horn
 It chiefly contains motor nerve fibres
2. Lateral funiculus/ white column:
 It is present between anterior and posterior horn of grey matter
3. Posterior funiculus/ white column:
 It is present between postero-median fissure and postero-lateral sulcus
 It contains sensory nerve tracts

10.  Gray matter: Look like H shaped, It shows 2 horns:
1. Anterior horn
 Directed to anterolateral side
 Smaller in length but broader in width
2. Posterior horn
 Directed to postero-lateral side
 Longer and narrower
3. Additional Lateral horn for the supply of viscera at the level of T1-L2 and S2-S4
segments (part of ANS)

11. Clinical anatomy
 Conus medullaris syndrome: Injury to S2, S3, S4 segments of spinal cord
 Cauda equina syndrome: Damage to cauda equina
 Poliomyelitis: It is a viral disease which involves anterior horn cells
 Tabes dorsalis: Degenerative lesions of dorsal nerve roots and of
posterior white columns

12. Reference
 B D Chaurasia’s Human Anatomy (Volume 4) 7th edition

13. Thank you…