Cranial Nerves and Nuclei

Question 1

Describe the olfactory pathway?

Answer 1

1) There are receptor cells in the olfactory epithelium
2) These pass up through the cribriform plate of the ethmoid
3) These synapse in the olfactory bulb (visible on inferior aspect of the brain)
4) The neurons pass along the olfactory tract
5) The olfactory cortex which processes the smell is plugged directly into the olfactory tract
note this is only nerve that does this the rest have to plug into the cortex first

Question 2

What modality does the olfactory nerve have?

Answer 2

Special sensory

Question 3

What nucleus does the motor fibres for the oculomotor nerve originate in?

Answer 3

The oculomotor nucleus

Question 4

What nucleus do the preganglionic parasympathetic neurones from the oculomotor nerve originate in?

Answer 4

The Edinger Westphal nucleus

Question 5

What originates in the Edinger-Westphal nucleus?

Answer 5

preganglionic parasympathetic neurones from the oculomotor nerve

Question 6

What originates in the oculomotor nucleus ?

Answer 6

Motor fibres for the oculomotor nerve

Question 7

Where is the oculomotor nucleus located?

Answer 7

In the rostral midbrain

Question 8

Where are do the motor fibres for the trochlear nerve originate?

Answer 8

In the trochlear nucleus

Question 9

The fibres of the trochlear nerve _______ so _____

Answer 9

exit posteriorly and cross sides so the right nerve supplies the left eye and vice versa

Question 10

What originates in the trochlear nucleus?

Answer 10

Motor fibres for the trochlear nerve

Question 11

Where do the motor fibres for the abducent nerve originate?

Answer 11

in the abducens nucleus

Question 12

Where is the abducens nucleus located?

Answer 12

In the Pons below the 4th ventricle

Question 13

What originates in the abducens nucleus?

Answer 13

Motor fibres for the abducent nerve

Question 14

Where do motor fibres for the hypoglossal nerve originate?

Answer 14

In the hypoglossal nucleus

Question 15

What originates in the hypoglossal nucleus?

Answer 15

Motor fibres for the hypoglossal nerve

Question 16

Where does the spinal accessory nerve originate?

Answer 16

In the accessory nucleus

Question 17

Where is the accessory nucleus?

Answer 17

In the cervical spinal cord

Question 18

What originates from the accessory nucleus?

Answer 18

The motor fibres for the spinal accessory nerve

Question 19

What nuclei contribute to the trigeminal nerve?

Answer 19

Mesencephalic nucleus
Pontine trigeminal nucleus
Spinal trigeminal nucleus
Trigeminal motor nucleus

Question 20

What fibres does mesencephalic nucleus provide?

Answer 20

Sensory

proprioreception from chewing for the trigeminal nerve

Question 21

What fibres does the pontine trigeminal nucleus provide?

Answer 21

sensory

discriminative touch, vibration for the trigeminal nerve

Question 22

What fibres does the spinal trigeminal nucleus provide?

Answer 22

Pain and temperature
for the trigeminal nerve
(also small amount of somatosensation to the ear for vagus, glossopharyngeal and facial and vagus pain from dura)

Question 23

What fibres does the trigeminal motor nucleus provide?

Answer 23

motor to the muscles of mastication, tensor tympani, mylohyoid, ant. belly of digastric, tensor veli palatini

Question 24

What nuclei contribute to the facial nerve?

Answer 24

Facial motor nucleus
Salivatory nucleus
Solitary nucleus
Spinal trigeminal nucleus

Question 25

What fibres does the facial motor nucleus provide?

Answer 25

Motor fibres for the muscles of facial expression

Question 26

What fibres does the salivary nucleus provide?

Answer 26

Parasymaptehtic innervation to salivary glands for facial and glossopharyngeal

Question 27

What fibres does the solitary nucleus provide?

Answer 27

special sensory taste and visceral information

for facial, glossopharyngeal and vagus

Question 28

What nuclei contribute to the glossopharyngeal nerve?

Answer 28

Solitary nucleus
Nucleus ambiguus
Salivatory nucleus
Spinal trigeminal nucleus

Question 29

What fibres does the nucleus ambiguus provide?

Answer 29

motor to the pharynx and larynx

for glossopharyngeal and vagus

Question 30

What nuclei contribute to the vagus nerve?

Answer 30

Dorsal (motor) nucleus
Solitary nucleus
Spinal trigeminal nucleus
Nucleus ambiguus

Question 31

What fibres does the dorsal (motor) nucleus provide?

Answer 31

Parasympathetic fibres for the vagus

Question 32

The ___________ tract is part of the pyramidal tract that provides motor to the cranial nerves

Answer 32

corticobulbar

Question 33

Describe what the reticular formation is

Answer 33

The reticular formation is a network of loosely aggregated cells with cell bodies, axons and dendrites intermingling in the central core of the brainstem. It is distinct from the long pathways (like the medial lemniscus, or the corticospinal tract) and the specific distinct cell groups (like cranial nerve nuclei).

Question 34

Describe the functions of the reticular formation

Answer 34

Integrate cranial nerve reflexes.
Participate in conduction and modulation of pain.
Influence voluntary movement.
Regulate autonomic activity.
Integrate some basic functions, like respiration and sleep.
Activate the cerebral cortex: major component of the Ascending Reticular Activating System (a medial bilateral lesion of the brainstem reticular formation at or above the upper pons causes irreversible coma).