Lecture 3 - Brainstem Overview

Question 1

Ascending tracts of the Brain Stem:

Spinothalamic tract –> carries sensations of _____ and _____.

Medial Lemniscus –> caries sensations of _____ position, ______, and fine ______.

Spinocerebellar –> carries proprioceptive info.

Answer 1

Pain and Touch

Joint position

Vibration

Fine touch

Question 2

All the cranial nerves exit on the _____ side, except for Cranial Nerve (CN) ____, which exits on the _____ side.

Answer 2

Ventral

IV

Dorsal

Question 3

The Superior Colliculus and Inferior Colliculus are related to the _____ and _____ geniculate nuclei, respectively.

With that in mind, which conveys Auditory sensation and which conveys Visual sensation?

Answer 3

Superior Colliculus –> Lateral GN

Inferior COlliculus –> Medial GN

Superior (Lateral GN) –> Visual

Inferior (Medial GN) –> Auditory

Question 4

Define/Describe the numbered areas in this Transverse Section of the Midbrain

Answer 4

1. Inferior Colliculus –> brainstem relay for hearing info
2. Medial Longitudinal Fasciculus –> Carries fibers that coordinate the movements of our Eyes, Head, and Neck when responding to visual stimuli (coordinates processes within the brain ONLY, especially maintaining visual focus while turning head away from visual stimulus)
3. Medial Lemniscus –> Relays sensations of touch and proprioception to the forebrain
4. Cerebral Peduncle –> Delivers info from the cerebral cortext to the Cerebellum and Motor commands to the Spinal cord
5. Substantia Nigra –> Produces dopamine (part of the basal ganglia)
6. Superior Cerebellar Peduncle –> Carries info from the Cerebellum to the Cerebral Cortex
7. Cerebral Aqueduct –> Passes CSF to the Fourth Ventricle to the Brainstem

Question 5

What is area 4 labeled in the pic?

Answer 5

Middle Cerebral Peduncle of the Pons –> Delivers info from the Cerebral Cortex to the Pontine Nuclei