Anatomy of the Spinal Cord

Question 1

Spinal Canal - Characteristics and What Does it Contain?

Answer 1

Formed by vertebral foramina.
Diameter varies from 12-22mm in cervical region and 22-25mm in lumbar region.
Contains:
- spinal cord
- meninges
- Blood vessels
- Spinal nerve roots and surrounding fatty and connective tissue.

Question 2

Function of the Spinal Cord

Answer 2

Receives sensory information about the environment.
Carries all the information that supplies voluntary muscles.
Channel for the longitudinal flow of information to and from the brain.

Question 3

Anatomy of the Spinal Cord - Characteristics

Answer 3

Continuous with the brainstem and ends at medullary cone L1-L2 level. 45 cm in length.
Formed by thousands axons surrounding a central core of gray matter.

Question 4

At what level is the Cauda Equina?

Answer 4

L2-S5

Question 5

Terminal Filum

Answer 5

Becomes a component of the coccygeal ligament.
Thickening of the pia mater that anchors the spinal cord to the sacrum.

Question 6

Meninges - Function and Layers

Answer 6

Enclose the spinal cord for protection.
- Dura mater
- Arachnoid mater
- Pia mater
Continuous with the brain.

Question 7

Dura Mater - Characteristics and Location

Answer 7

Though, thick layer of connective tissue.
Extends from the foramen magnus to the filum terminale.
Surrounded by epidural space filled with loose areolar connective tissue, fat and blood vessels.

Question 8

Epidural vs. Spinal Anesthesia

Answer 8

Epidural: does not cross the dura mater. Not blocking the whole conduction of pain info.
Spinal: Crosses the dura mater. Blocks all conduction of pain info.

Question 9

Arachnoid Mater - Characteristics

Answer 9

Separated from dura mater by subdural space.
Separated from pia mater by subarachnoid space which contains cerebrospinal fluid.

Question 10

Where is the target site for lumbar puncture or spinal tap?

Answer 10

Large lumbar cistern of subarachnoid space filled with CSF around conus medullaris and cauda equina.

Question 11

Pia Mater - Characteristics

Answer 11

Delicate membrane attached to the spinal cord, including ventral median fissure and dorsal median sulcus, and extends 20cm to the coccyx as filum terminale.

Question 12

Spinal Cord Blood Supply

Answer 12

Segmental Spinal (or vertebral) arteries.
- Single anterior spinal artery
- Paired posterior spinal arteries
- Anterior and posterior radicular arteries
- Arterial vasocorona (connection between spinal arteries)

Question 13

Paired vertebral arteries - Supply Areas and Location/Pathway

Answer 13

Upper part of spinal cord, brainstem, cerebellum, posterior part of the brain.
Originate in the subclavian artery, goes up on the sides of the neck, merging with each other at the pons level to form the basilar artery.
Basilar artery and the internal carotid arteries form the circle of Willis.

Question 14

Anterior Spinal Artery(x1) - Supply Areas (6)

Answer 14

Anterior gray column of spinal cord
Lateral gray column of spinal cord
Central gray matter
Anterior funiculus
Lateral funiculus
Anterior portion of posterior gray matter

Question 15

Posterior Spinal Arteries (x2) - Supply Areas (2)

Answer 15

Posterior portion of posterior gray matter
Posterior funiculus

Question 16

Radicular Arteries - Supply Areas (3)

Answer 16

Entire length of spinal cord.
Spinal Nerve Roots
Anterior and posterior spinal arteries

Question 17

Arterial Vasocorona - Supply Area (1)

Answer 17

Pia mater of spinal meninges

Question 18

Different Components of the Spinal Cord (3)

Answer 18

Gray matter with central canal
White matter
Dorsal horn and ventral horn (merge to form a spinal nerve) (Dorsal root coming from the gray matter and Ventral root coming from the white matter).