Spinal Cord

Question 1

Which layers cover the spinal cord?

Answer 1

Dura, subarachnoid, pia

Question 2

Which layer contains CSF?

Answer 2

Subarachnoid. Central canal contains CSF.

Question 3

What is the function of the spinal cord?

Answer 3

Provides autonomic innervation of most viscera.

Question 4

Where does the spinal cord end?

Answer 4

Between first and second lumbar vertebrae. Ends as filum terminale.

Question 5

What structure forms as the spinal cord tapers off?

Answer 5

Conus medullaris

Question 6

What name is given to the spinal nerves that arise from the end of the spinal cord?

Answer 6

Cauda equina

Question 7

Name the 4 columns of the spinal cord.

Answer 7

Dorsal horn
Ventral horn
Intermediate column
Lateral horn

Question 8

What is the function of the dorsal horn?

Answer 8

1. Contains neurones that receive somatosensory information from the body.
2. Transmits information via ascending pathways to the brain

Question 9

What is the function of the ventral horn?

Answer 9

Contains motor neurones that exit the spinal cord to innervate skeletal muscle.

Question 10

What are the functions of the intermediate column and lateral horn?

Answer 10

Contain neurones that innervate visceral and pelvic organs.

Question 11

What does the spinal nerve divide into when it leaves the vertebral canal?

Answer 11

Posterior and anterior rami

Question 12

What are the 31 paired spinal nerves?

Answer 12

8 cervical, 12 thoracic, 5 lumbar, 5 sacral, 1 coccygeal

Question 13

Is the dorsal root sensory or motor?

Answer 13

Sensory

Question 14

Is the ventral root sensory or motor?

Answer 14

Motor

Question 15

Which arteries supply the spinal cord?

Answer 15

Anterior spinal artery > Paired posterior spinal arteries > Anterior and posterior segmental medullary arteries

Question 16

Which veins drain the spinal cord?

Answer 16

Anterior and posterior spinal veins > Internal and external vertebral plexuses

Question 17

Which stain is used to stain white matter black?

Answer 17

Osmium. Stains myelin.

Question 18

Which stain is used to stain grey matter black?

Answer 18

Silver stain. Stains cell body.

Question 19

How many laminae are in grey matter?

Answer 19

10

Question 20

Is the fasciculus gracilis an ascending or descending tract?

Answer 20

Ascending.

Carries proprioception and vibration information from the lower body to gracile tubercle in medulla.

Question 21

Is the fasciculus cuneatus an ascending or descending tract?

Answer 21

Ascending.

Carries proprioception and vibration information from upper body to cuneate tubercle in medulla.

Question 22

Is the spinothalamic tract ascending or descending?

Answer 22

Ascending.

Lateral side carries pain & temperature information. Medial side carries crude touch information. Both sides ascend on the same side for 1/2 segment, decussate and join at the medulla. Cell bodies are in dorsal root ganglion.

Question 23

Is the lateral corticospinal tract ascending or descending?

Answer 23

Descending.

Begins in primary motor cortex. Medulla decussation. Transmits control of voluntary limb muscles.

Question 24

Is the ventral corticospinal tract ascending or descending?

Answer 24

Descending.

Begins in primary motor cortex. Decussates as it leaves the anterior white commissure. Transmits control of voluntary axial muscles.

Question 25

What are fasiculi?

Answer 25

Nerve axons running up and down the spinal cord in bundles.

Question 26

What are upper motor neurones and what do they do?

Answer 26

Neurones that originate in the cerebral cortex and brainstem. They control movement, muscle tone, spinal reflexes.

Question 27

What are lower motor neurones and what do they do?

Answer 27

Neurones that originate in the anterior grey column, cell bodies in brainstem. They receive signals from UMN and transmit these to muscle fibres.

Question 28

Upper motor neurones are divided into two types. Give these.

Answer 28

Pyramidal and extrapyramidal.

Question 29

What are pyramidal UMN?

Answer 29

2 neurone pathway that originates in the cerebral cortex. Decussate in the medulla and descend contralaterally. Synapse with cell bodies of the ventral horn of the spinal grey matter.

Question 30

What are extrapyramidal UMN?

Answer 30

Originate in brainstem. Carry motor fibres to spinal cord. Responsible for involuntary autonomic control of all musculature.

Question 31

Name the 4 sensory nerve endings that can sense fine touch.

Answer 31

1. Meissner's corpuscle 2. Pacinian corpuscle 3. Ruffini endings 4. Merkel endings

Question 32

What is Brown-Sequard syndrome?

Answer 32

A hemi-section of the spinal cord.

Question 33

What occurs as a result of Brown-Sequard syndrome?

Answer 33

Ipsilateral loss of: proprioception, motor & fine touch a few segments below the level of damage. Descending corticospinal tract is damaged. Contralateral loss of: pain, temperature & crude touch a few segments below the level of damage.