Mod5-Obj3: White matter

Question 1

White matter

Answer 1

Superficial to gray matter (opposite to the brain)

-Composed of myelinated (mainly) and unmyelinated axons

Question 2

White matter is organised into white columns:

Answer 2

• Posterior (dorsal) white columns
• Lateral white columns
• Anterior (ventral) white columns

Question 3

Anterior white commissures

Answer 3

Site of axon cross over

Question 4

The axons within the white matter are functionally organised into

Answer 4

Spinal tracts

Question 5

Spinal tracts:

Answer 5

Subdivision of a white column

• Spinal cord section of a multi-neuron pathway
• collection of axons

Question 6

The axons in each tract are functionally the same

Answer 6

The relay:

• The same type of information
• In the same direction
• To the same destination
• At the same conduction speed

Question 7

Spinal cord tracts

Answer 7

Relay information between spinal cord segments or, between the spinal cord and brain

Question 8

Ascending tracts

Answer 8

Spinal cord portion of a multi-neuron pathway that relays sensory information

Question 9

Descending tracts

Answer 9

Spinal cord portion of a multi-neuron pathway that relays motor information

Question 10

Ascending spinal cord tracts: Fasciculus gracilis & Fasciculus cuneatus

Answer 10

White column location: Posterior white columns
Sensory information relayed:
-Fine touch
-Vibration
-Pressure
-Proprioception

Question 11

Ascending spinal cord tracts: Lateral spinothalamic

Answer 11

White column location: Lateral white columns
Sensory information relayed:
-Pain
-Temperature

Question 12

Ascending spinal cord tracts: Spinocerebellar (anterior & posterior)

Answer 12

White column location: Lateral white columns
Sensory information relayed:
-Proprioception

Question 13

Ascending spinal cord tracts: Anterior (ventral) spinothalamic

Answer 13

White column location: anterior white columns 
Sensory information relayed:
-Crude touch (can't localise)
-Pressure
-Tickle & itch

Question 14

Descending cord tracts: Lateral coticospinal tracts

L FOR LATERAL, L FOR LIMBS

Answer 14

White column location: Lateral white columns
Motor commands relayed:
-Voluntary motor commands that control the skeletal muscles of the limbs

Question 15

Descending cord tracts: Anterior (ventral) corticospinal tracts
A FOR ANTERIOR, A FOR AXIAL

Answer 15

White column location: Anterior white columns
Motor commands relayed:
-Voluntary motor commands that control the skeletal muscles of the axial skeleton, pectoral girdle, pelvic girdles