Spinal cord, ascending and descending pathways

Question 1

How many pairs of spinal nerves are there?

Answer 1

31

Question 2

What are the 2 enlargements of the spine?

Answer 2

• cervical enlargement

- lumbar enlargement

Question 3

Posterior roots are motor/sensory, whilst anterior roots are motor/sensory.

Answer 3

Posterior roots = sensory

Anterior roots = motor

Question 4

The _____ ligament suspends the spinal cord

Answer 4

Denticulate ligament

Question 5

The inner H of the spinal cord is the ____ matter

Answer 5

H = grey matter

Question 6

What is contained within the central canal of the spinal cord?

Answer 6

CSF

Question 7

What arteries suppl the spinal cord?

Answer 7

3 longitudinal arteries

• 1 anterior
• 2 posterior

segmental arteries

radicular arteries

Question 8

Where is the epidural space found? What does it contain?

Answer 8

Epidural space is between dura matter and bone. Contains:

• epidural venos plexus
• adipose

Question 9

What is the main neural tract conveying touch, vibration and prorioception up to the somatosensory cortex?

Answer 9

The Dorsal Column Medial Lemniscus System

Question 10

The Dorsal colum medial lemniscus fibres cross in the _____

Answer 10

medulla

Question 11

The Dorsal column medial lemniscus system second order fibres synapse in the _____

Answer 11

thalamus

Question 12

What modalities are carried up to the somatosensory cortex by the Spinothalamic Tracts (anterior and lateral)?

Answer 12

Anterior Spinothalamic tract:

• crude touch
• pressure

Lateral Spinothalamic tract:

• Pain
• Temperature

Question 13

The Spinothalamic tract fibres cross at the _____

Answer 13

spinal cord level

Question 14

Where in the brain do the spinothalamic tract second-order fibres synapse?

Answer 14

Thalamus, with third-order neurons that travel to somatosensory cortex

Question 15

Where in the cerebrum is the primary somatosensory cortex located?

Answer 15

postcentral gyrus

Question 16

What’s the location of the primary motor cortex in the brain?

Answer 16

precentral gyrus (of the cerebral cortex)

Question 17

Name the descending (motor) spinal tract.

Answer 17

-Corticospinal (Pyramidal) tract

Extrapyramidal:

• Tectospinal tract
• Reticulospinal tract
• Vestibulospinal tract

Question 18

What is the modality of the corticospinal tract?

Answer 18

fine, precise movement

Question 19

Where do most of the fibres of the corticospinal tract decussate?

Answer 19

medulla

Question 20

How does a Cardiovascular Accident (CVA) at the internal capsule affect the Corticospinal tract, i.e. what is the clinical picture?

Answer 20

spastic paralysis (decorticate posturing)

Question 21

What reflex is mediated by the Tectospinal tract?

Answer 21

Head/neck movements due to visual stimul

-e.g. turning towards moving object

Question 22

Reticulospinal tract fibres originating

• in the pons facilitate flexor/extensor movements;
• in the medulla facilitate flexor/extensor movements

Answer 22

pons = extensor

medulla = flexor