Anatomy of the Cranial Nerves and Nuclei

Question 1

Label the inferior view of the Cranial Nerves

Answer 1

Question 2

Label the anterior view of the brainstem

Answer 2

Question 3

Label the posterior view of the brainstem

Answer 3

Question 4

Where is the Olfactory Nerve located and where is its nucleus?

Answer 4

Question 5

At what level of the brain are the following cranial nerves located?

III Oculomotor

IV Trochlear

VI Abducens

XII Hypoglossal

Answer 5

Question 6

Label the diagram for the Oculomotor centres

Answer 6

Edinger-Westphal Nucleus (pregnaglionic parasympathetic nucleus)

Oculomotor nucleus (somatic motor nucleus)

Question 7

Identify the Nuclei of the Oculomotor Nerve

Answer 7

ORANGE

Edinger-Westphal Nucleus (pregnaglionic parasympathetic nucleus)

RED

Oculomotor nucleus (somatic motor nucleus)

Question 8

Label the diagram for the Tochlear nucleus

Answer 8

Question 9

Identify the Trochlear Nucleus

Answer 9

Question 10

Label the Abducens Nucleus

Answer 10

Question 11

Identify the Abducens Nucleus

Answer 11

Question 12

Label the diagram of the hypoglossal nucleus

Answer 12

Question 13

Identify the hypoglossal Nucleus

Answer 13

Question 14

Label these Cranial Nerves

Answer 14

Question 15

Label the diagram of the Spinal Accessory Nerve

Answer 15

Question 16

List the Functions of the Trigeminal Nerve

Answer 16

Functions:

1. Somatosensation of face: discriminative touch, vibration sense, pain, temperature
2. Proprioception associated with chewing (TMJ, muscles of mastication, teeth
3. Motor control: muscles of mastication, tensor tympani, mylohyoid, ant. belly of digastric, tensor veli palatini

Question 17

Label the diagram of the Trigeminal Sensory Nuclei

Answer 17

Question 18

Describe the Trigeminal Nucleus and its parts

Answer 18

The sensory nucleus of the trigeminal forms a long column of neurons that stretches from the midbrain down to the upper 2 segments of the cervical spinal cord. It has 3 parts, separated by function.

Question 19

What is the function of the Mesencephalic Nucleus?

Answer 19

Trigeminal Nerve Proprioceptive information from teeth and jaw arrive at the mesencephalic nucleus. Proximity to motor nucleus offers obvious advantages in terms of jaw reflexes.

The mesencephalic nucleus is very unusual, it is the only site in the CNS where the cell bodies of the primary afferent neurons live inside the CNS. It is essentially a ‘retained’ sensory ganglion.

Question 20

What is the function of the Pontine Trigeminal Nucleus (Principal Nucleus)

Answer 20

Trigemnial Nerve discriminitive touch & vibration

Question 21

What is the function of the Spinal Nucleus?

Answer 21

Trigeminal Nerve Pain and Temperature

Question 22

Identify Trigeminal Nerve Nuclei

Answer 22

Question 23

Describe the function of the Facial nerve

Answer 23

1. Motor (muscles of facial expression, stapedius).
2. Parasymp. innervation to pterygopalatine and submandibular ganglia.
3. Taste (anterior 2/3 of tongue via c. tympani).

Question 24

Describe the function of the Glossopharyngeal nerve

Answer 24

1. Tactile sense, pain and temperature sense from the posterior tongue pharyngotympanic tube and upper pharynx.
2. Taste (posterior 1/3 of the tongue).
3. Parasympathetic fibres to the otic ganglion (parotid gland).
4. Motor (one muscle: stylopharyngeus)

Question 25

Describe the function of the Vagus Nerve

Answer 25

1. Tactile sense, pain and temperature sense from the pharynx, larynx, trachea, oesophagus and thoracic and abdominal viscera.
2. Taste (epiglottis)
3. Parasympathetic innervation to ganglia serving thoracic and abdominal viscera.
4. Motor (striated muscle of the pharynx and larynx) (cranial accessory contributes to this function).

Question 26

Label the diagram of the Facial Nerve Nuclei

Answer 26

Question 27

Label diagram of the Glossopharyngeal Nuclei

Answer 27

Question 28

Label the component of the Vagus nerve nuclei

Answer 28

Question 29

What is the function of the Solitary Nucleus?

Answer 29

CNs VII, IX, X

taste and visceral sensory information

Question 30

What is the functio of the Superior and Inferior Salivatory nuclei?

Answer 30

CN VII and IX

parasympathetic efferents to ganglia of salivary glands and pterygopalatine ganglion

Question 31

What is the function of Nucleus Ambiguus?

Answer 31

CN’s IX and X (and cranial part of XI)

motor efferents to muscles of pharynx, larynx and upper oesophagus

Question 32

Label the diagram of the Solitary Nucleus

Answer 32

Question 33

Identify the location of the solitary Nucleus on the sections

Answer 33

Question 34

Identify the Location of Nucleus Ambiguus

Answer 34

Lower Pons / Upper Medulla

Question 35

What is the corticobulbar tract?

Answer 35

The corticobulbar tract is the part of the pyramidal tract that is motor to cranial nerves.

This includes fibres to the motor nuclei of CN’s V, VII, X, and XII.

Question 36

Label the diagram of the corticobulbar tract

Answer 36

Question 37

What is the reticular formation?

Answer 37

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 38

What is the function of the reticular formation?

Answer 38

The reticular formation includes centres that:

• 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).