Midbrain

Question 1

The tectum (roof) of the midbrain is defined by what?

Answer 1

Corpora quadrigemina (Superior and Inferior colliculi)

Question 2

What structure separates the tegmentum from the crus cerebri? (Midbrain)

Answer 2

Substantia nigra

Question 3

What surrounds the cerebral aqueduct?

Answer 3

Periaqueductal gray (PAG)

Question 4

What two cranial nerves emerge from the midbrain?

Answer 4

• CN III (Oculomotor)

- CN IV (Trochlear)

Question 5

The inferior colliculus is an afferent relay center for the ____ tract

Answer 5

Auditory

Question 6

The primary afferent of the auditory pathway begins where?

Answer 6

Spiral ganglion of the cochlea (within bony modiolus)

Question 7

The second order fibers of the auditory pathway begin where?

Answer 7

Ventral and Dorsal Cochlear Nuclei (rostral medulla)

Question 8

The inferior colliculus projects the auditory axons to where?

Answer 8

Medial Geniculate Nucleus of thalamus

Question 9

The periaqueductal gray contains high concentrations of the neurotransmitter peptide _____

Answer 9

Enkephalin

Question 10

The trochlear nerve innervates what muscle of the eye?

Answer 10

Superior oblique

Question 11

Diplopia means what?

Answer 11

Double vision

Question 12

Parkinson’s disease is associated with loss of dopaminergic neurons in the ______ (part of the midbrain)

Answer 12

Substantia nigra (specifically the pars compacta=medial portion)

Question 13

The superior colliculus receives ____ inputs

Answer 13

Visual (retinal)

Question 14

The superior colliculus projects axons to the cervical spinal cord via the ____ tract

Answer 14

Tectospinal

Question 15

The trochlear nerve (CN IV) is strictly a ___ nerve (3 letter classification)

Answer 15

GSE

Question 16

The Oculomotor nerve (CN III) contains what classification axons?

Answer 16

GSE and GVE

Question 17

The ____ _____ (rostral midbrain) is important because it supplies all levels of the spinal cord and facilitates the discharge of flexor motor neurons. It also projects to the inferior olivary nucleus

Answer 17

Red nucleus

Question 18

The tegmentum portion of the midbrain can also be known as the ______

Answer 18

Reticular formation

Question 19

The most common disorders of the midbrain result mainly from vascular lesions of branches of the ____ artery, but may also derive from tumors such as those situated in the region of the pineal gland

Answer 19

Posterior cerebral

Question 20

The superior colliculus projects visual sensory fibers to the _____ of the thalamus

Answer 20

Lateral geniculate nucleus

Question 21

The ___ tract, originating in the superior colliculus, controls movements of the head and neck due to auditory and visual cues. It also plays a role in tracking movements of the eyes.

Answer 21

Tectospinal tract

Question 22

This structure regulates position of the yes in response to vestibular input (inner ear/balance)

Answer 22

Medial Longitudinal Fasciculus (MLF)

Question 23

This structure contains ascending fibers from the cerebellum to the red nucleus and thalamus

Answer 23

Superior cerebellar peduncle

Question 24

This structure mediates lateral movement of the ipsilateral eye

Answer 24

Trochlear nerve (CN IV)

Question 25

This structure contains descending fibers mediating inhibition of pain. It also regulates emotional behavior including fear, flight, anxiety, and rage behavior.

Answer 25

Periaqueductal gray (PAG)