Lecture 5/6: Spinal cord/Brainstem 1

Question 1

Label

Answer 1

Question 2

Function of the superior and inferior colliculi?

Answer 2

Superior = eye reflex to flashes

inferior = reflex to auditory stimulus

This means that even blind or deaf people can sometimes still be aware that something is going on out of the normal.

Question 3

Reason for Pars basilaris

Answer 3

This is the bulge in the pons and is due to the pontine nuclei that are for the cranial nerves.

Question 4

Importance of the pyramids?

Answer 4

Found at the bottom of the medulla

This is the point where 85% of the the UMNs decussate from the motor tract to the spinal cord and head down the lateral funiculus/motor columns = lateral corticospinal tract

The other 15% do not decussate here and instead head down the verntal corticospinal tract. (thought to be involved with postural core muscles)

Question 5

Path of discrimintive senation from spinal cord to 1˚ sensory cortex

Answer 5

1. Head up dorsal funiculus
2. synapse with internal arcute fibres at the gracile and cuneate nuclei found at the bottom of the brainstem
3. decussate and head up the medial lemniscal tract
4. travel up through the tegmentum to the VP L/M of the thalamus
5. travel in the internal capsuel to the cortex
6. ends up in lamina IV of the neocortex

Question 6

Path of pain and temp from spinal cord to cortex?

Answer 6

1. After deccussating at the individual spinal level via the ventral white commissure the fibres head up the lateral spinothalamic tract
2. They join the medial lemniscal tract at the pons and follow the same path as discriminitive sensation
3. Go to lamina IV of the neocortex