GS - Structure and Function of Spinal Cord

Question 1

Where are the 2 spine enlargements?

Answer 1

Cervical (C4 - T1)

Lumbosacral (L2-S3)

Due to arms and leg nerves branching off

Question 2

Which vertebral level does the spinal cord end in an adult?

Answer 2

L1-L2

Question 3

At which level would you sample CSF by lumbar puncture and how would you identify this practically ?

Answer 3

L3 - 4 space
or
L4 - 5 space

Palpating the right and left posterior superior iliac crests and moving the fingers medially toward the spine

Palpate that interspace (L3-L4), the interspace above (L2-L3), and the interspace below (L4-L5) to find the widest space

Question 4

How does the cross section of the spinal cord change ?

Answer 4

Bulges due to limb grey matter (cervical, lumbosacral)

White matter increases up cord (accumulated neuronal traffic to and from brain)

Question 5

In this HISTOLOGICAL VIEW of the spinal cord label the right side (with an R) and the dorsal aspect (with a D)

Answer 5

Image

Question 6

Label this cross section

Answer 6

Image

Question 7

Put these sections in order from rostral to caudal ?

Answer 7

Image

Question 8

What pathways is this?

Answer 8

Anterolateral pathway

Question 9

What pathways is this?

Answer 9

Dorsal column pathway

Question 10

What pathways is this?

Answer 10

Corticospinal tract

Question 11

What type of information do the gracile and cuneate tracts carry?

Answer 11

Conscious proprioception, vibration, light touch

Question 12

Where does the dorsal column pathway cross the midline?

Answer 12

Medulla

Question 13

What information does the anterolateral (also known as spinothalamic) pathway carry?

Answer 13

Pain, temperature, itch, touch

Question 14

Where does the anterolateral (also known as spinothalamic) pathway cross over the midline?

Answer 14

Spinal cord at or near the level of entry

Question 15

What type of information to spinocerebellar tracts carry ?

Answer 15

Unconcious proprioception

Question 16

Where does the spinocerebellar cross the midline?

Answer 16

Dont cross!

Question 17

What information does the corticospinal tract carry ?

Answer 17

Motor from cerebral cortex

Question 18

Where does the corticospinal tract cross over the midline?

Answer 18

Medulla and spinal cord

Question 19

What is Brown-Séquard Syndrome and what does it affect ?

Answer 19

Brown-Séquard syndrome is caused by damage to one half of the spinal cord, i.e. hemisection of the spinal cord

Results in paralysis and loss of proprioception on the same (or ipsilateral) side as the injury or lesion, and loss of pain and temperature sensation on the opposite (or contralateral) side as the lesion.

Question 20

How is the spinal cord supplied with blood?

Answer 20

Posterior spinal arteries;
From the cerebral arteries and posterior inferior cerebellar arteries. These arteries are paired.

Anterior spinal artery;
From the vertebral arteries

Segmental arteries;
From the vertebral arteries, cervical arteries, lumbar arteries

Medullary arteries;
Can anastomose with anterior spinal artery

And 1 more special artery ….

Question 21

What is the special artery that supplies the spinal cord at level 9th to 12th intercostal?

Answer 21

Artery of Adamkiewicz;
Typically arises from left posterior intercostal artery at the level of the 9th to 12th intercostal artery, which branch from the aorta, and supplies the lower two thirds of the spinal cord via the anterior spinal artery

Careful manipulation of aorta during surgical procedures, between segments which give off branches of 9th to 12th intercostal artery, to prevent blockage of the artery of Adamkiewicz

Question 22

What is anterior cord syndrome and what does it cause?

Answer 22

Where the anterior spinal artery is blocked.

Causes a loss of all motor control below lesion as well as the loss of pain and temperature at and below the level of the lesion

Question 23

What is central cord syndrome/Sphingomyelia and what does it cause?

Answer 23

The syndrome disproportionately affects the spinothalamic (pain and temperature) and corticospinal (motor) tracts, both located in the anterior two-thirds of the human spinal cord, while typically sparing the posterior columns (light touch and proprioception).

Question 24

What information does the Rubrospinal tract carry and where does it fibres cross the midline?

Answer 24

The Rubrospinal tract controls muscle tone in flexor muscle groups (it is particularly important in the term newborn because of the flexor tone in the limbs).

Rubrospinal fibers cross in the ventral tegmental decussation of the midbrain

Rubrospinal tract is a descending pathway, beginning as axons of the neurons present in the red nucleus and terminates by synapsing with the interneurons in the spinal cord. It is part of the extrapyramidal system and is important for regulating the activity of the motor neurons.

Question 25

What information does the Reticulospinal tract carry and where does it fibres cross the midline?

Answer 25

Reticulospinal tract carries information or orders from the reticular formation in the brainstem to the peripheral body part

Dosent cross, is ipsilateral

Question 26

What information does the Vestibulospinal tract carry and where does it fibres cross the midline?

Answer 26

Vestibulospinal tract maintains equilibratory reflexes from the input of the vestibular apparatus (e.g if falling medial for head to go back, lateral for arms to go out)

Doesn’t cross, ipsilateral

Question 27

What information does the Spinocerebellar tract carry and where does it fibres cross the midline?

Answer 27

The spinocerebellar tracts carry unconscious proprioceptive information gleaned from muscle spindles, Golgi tendon organs, and joint capsules to the cerebellum.

Rostral pons/caudal midbrain is where the tract crosses the midline again to enter the cerebellum through the superior cerebellar peduncle.

Question 28

What is the correct order in cervical to sacral direction?

Answer 28

B, A, C

Question 29

A patient has a bilateral loss of pain and temperature and atrophy of muscles in both hands. Conscious proprioception is conserved. What is the most likely cause?

Answer 29

Sphingomyelia

Question 30

What is the function of the lateral corticospinal tract in the spinal cord ?

Answer 30

Controls fine flexor movement

Question 31

In which region of the spinal cord would you find this slice?

Answer 31

Thoracic as limbs are other 3