Tri B - Spinal Nerves

Question 1

What is the function of the spinal cord and cranial nerves?

Answer 1

Link for nerve impulses traveling to and from the brain
Processes reflex responses

Question 2

What anchors the spinal cord to the coccyx?

Answer 2

Filum Terminale

Question 3

Describe the spinal cord

Answer 3

Cylindrical - 42-45cm - 3/4” diameter
Slightly flattened neural tube
Tapers forming Medullary cone at L1/L2

Question 4

Describe the Cauda Equina

Answer 4

Loose bundle of spinal nerve roots arising from lumbar enlargement and medullary cone

Question 5

Describe the Terminal Filum

Answer 5

Arises from tip of medullary cone
An anchor for inferior spinal cord and meninges

Question 6

Describe the internal structure of the spinal cord

Answer 6

Enlarged in 2 areas
Cervical - most anterior rami arising from bronchial plexus
Lumbosacral - anterior rami make up lumbar sacral plexuses
Divided into 2 equal parts by
- Anterior median fissure
- Posterior median fissure
Grey matter in centre, surrounded by white matter

Question 7

Describe grey matter within the spinal cord

Answer 7

Butterfly shaped
2 posterior, 2 anterior, 2 lateral columns
Central canal contains CSF
Consists primarily of nerve cell bodies

Question 8

Describe white matter within the spinal cord

Answer 8

Arranged into 3 columns: anterior, posterior, lateral
Ascending tracts - sensory axons
Descending tracts - motor axons

Question 9

Describe protection of the spinal cord

Answer 9

Bony vertebrae
Surrounded by:
CSF
Spinal meninges

Question 10

Name the spinal meninges

Answer 10

1. Pia Mater
2. Arachnoid Mater
3. Dura Mater

Question 11

Describe the dura mater

Answer 11

Outer layer
Tough fibrous and elastic layer
Forms the spinal dural sac

Question 12

Describe the arachnoid mater

Answer 12

Middle layer
Delicate, avascular
Ensheaths spinal cord and nerve roots
Lines dural sac

Question 13

Describe the pia mater

Answer 13

Inner layer
Thin, connective tissue, close to contours
Covers spinal nerve roots
Contains small blood vessels
Spinal cord is suspended within Dural sac by 21 pairs of denticulate ligaments

Question 14

Describe the epidural space

Answer 14

Between bony wall of vertebrae and dura mater
Contains cushioning of fat, blood vessels and connective tissue
Runs length of vertebral canal

Question 15

Describe the sub arachnoid space

Answer 15

Between the arachnoid and pia mater
Spanned by arachnoid trabeculae
Filled with CSF

Question 16

Describe the spinal nerves

Answer 16

31 Pairs of spinal nerves
Arise from both sides, emerge from intervertebral foramina
Cervical x 8
Thoracic x 12
Lumbar x 5
Sacral x 5
Coccyx x1

Question 17

Describe nerve roots

Answer 17

Each nerve formed by sensory and motor nerve root