Brainstem - Midbrain

Question 1

superior colliculi

Answer 1

rostral tectum (dorsal)

visual relay station - visual tracking & head turning due to environmental stimuli
contains afferent fibers from retina and efferent fibers to cervical spine

Question 2

inferior colliculi

Answer 2

caudal tectum

auditory relay station - signal integration, fq recognition, pitch discrimination
contains afferent fibers from cochlea, superior olivary, trapezoid nuclei via lateral lemniscus and efferent fibers to thalamus

Question 3

substantia nigra

Answer 3

tegmentum (ventral)

basal ganglia, movement
dopamine producing

Question 4

ventral tegmental area

Answer 4

rostral tegmentum

largest collections of dopamine producing neurons
reward system, projects to limbic system & cortex

Question 5

red nuclei

Answer 5

rostral tegmentum

motor coordination & control for flexor muscles

Question 6

oculomotor nuclei

Answer 6

rostral tegmentum

Question 7

trochlear nuclei

Answer 7

caudal tegmentum

Question 8

superior cerebellar peduncle

Answer 8

caudal tegmentum (also rostral pons)

relay station to cerebellum
afferent & efferent fibers

Question 9

raphe nuclei

Answer 9

caudal tegmentum (also rostral pons)

serotonin producing

Question 10

crus cerebri

Answer 10

basis pedunculi

large bundles of somatotopically organized axons containing motor fibers

Question 11

cerebral peduncle

Answer 11

basis pedunculi + ventral tegmentum

= basis pedunculi + substantia nigra
two stalks that attach cerebrum to brainstem at ventral midbrain, arise from ventral pons
contains descending motor nerve tracts

Question 12

periaqueductal gray

Answer 12

tectum/tegmentum

gray matter surrounding cerebral aqueduct - stands alone
inhibition pain modulation, autonomic regulation, emotions

Question 13

midbrain external anatomy and function

Answer 13

CN 3, 4 emerge

vision, hearing, motor control, sleep & wake cycles, alertness, temp regulation