Structures of the Midbrain

Question 1

Superior Colliculi

Answer 1

Locations = Rostal Tectum

Function:
1. Visual relay station

2. Helps relay connections that correlate head and neck movements

Question 2

Inferior Colliculi

Answer 2

Location = Caudal Tectum

Function:
1. Auditory relay station

2. Helps relay connections from peripheral auditory structures (Ex: cochlea) to cortical auditory regions.

Question 3

Substantia Nigra

Answer 3

Location = Rostral and Caudal Tegmentum

Function:
1. Part of basal ganglia, involved in movement

2. Major dopamine-producing and storage areas

Question 4

Ventral Tegmental Area

Answer 4

Location = Rostral Tegmentum

Function:
1. Plays a role in reward system (reinforcing behavior), with projections to limbic system and cortex

2. Major dopamine-producing area

Question 5

Red Nuclei

Answer 5

Location = Rostral Tegmentum

Function = Motor coordination, motor control for flexor muscle groups

Question 6

Superior Cerebellar Peduncle

Answer 6

Location = Caudal Tegmentum

Function = Relay station to cerebellum

Question 7

Raphe Nuclei

Answer 7

Location = Caudal Tegmentum

Function = Major serotonin-producing neurons in the brain

Question 8

Crus Cerebri

Answer 8

Location = Basis Pedunculi

Function = Large bundles of somatotopically - organized axons containing fibers from motor pathways

Question 9

Cerebral Peduncle

Answer 9

Location = Basis Pedunculi + Substantia Nigra

Function:
1. Two stalks that attach the cerebrum to the brainstem at ventral surface of midbrain, arise from ventral pons.

2. Contain the large descending (motor) nerve tracts.

Question 10

Periaqueductal Gray

Answer 10

Location = Tectum/Tegmentum

Function:
1. Gray matter surrounding cerebral aqueduct

2. Pain modulation (primarily inhibition), autonomic regulation, emotion