The Cranial Nerves

Question 1

Olfactory Nerve (I)

Answer 1

Transmits sensory information from the nose, through the olfactory foramina, to the brain for the interpretation of odor.
Function: Smell
Origin: Nasal mucosa
Termination: Olfactory bulb-cerebrum
Passage: Olfactory foramina (Cribiform plate)

Question 2

Optic Nerve (II)

Answer 2

Transmits sensory information from the eyes, through the optic canals to the occipital lobe of the brain for the interpretation of vision.
Function: Vision
Origin: Retina
Termination: Thalamus-midbrain
Passage: Optic foramen (canal)
Contralateral- decussation at the optic chiasma

Question 3

Oculomotor Nerve (III)

Answer 3

Transmits motor impulse from the brain, through the superior orbital fissure, to control the shape of the lens of the eye, the pupil, and all extraocular eye muscles EXCEPT the lateral rectus and the superior oblique
Function: Involuntary- pupil, and lens focusing
voluntary- Eye movement, and opening of eyelid
Origin: Midbrain
Passage: Superior orbital fissure

Question 4

Trochlear Nerve (IV)

Answer 4

Transmits motor impulses from the brain, through the superior orbital fissure, to control the superior oblique muscle of the eye
Function: Eye movement
Origin: Midbrain
Termination: Superior oblique muscle
Passage: Superior orbital fissure
Damage: Causes double vision

Question 5

Trigeminal Nerve (V)

Answer 5

Contains 3 branches of functions:
-Ophthalmic branch (sensory): transmits sensory information from the frons through the superior orbital fissure, to the brain for the interpretation of touch
-Maxillary branch (sensory): transmits sensory information from the maxilla region, through the foramen rotundum, to the brain for the interpretation of touch
Mandibular branch (sensory and motor): transmits sensory information from the lower gums and teeth, through the foramen ovale, to the brain for the interpretation of touch. It also transmits motor impulses to the masseter and temporalis muscle for chewing

Termination: Pons

Question 6

Abducens Nerve (VI)

Answer 6

Transmits motor impulses from the brain, through the superior orbital fissure, to control the lateral rectus eye muscle
Function: Lateral eye movement
Origin: Pons
Termination: Lateral rectus muscle
Passage: Superior orbital fissure
Damage: Results in inability to rotate eye laterally and at rest eye rotates medially

Question 7

Facial Nerve (VII)

Answer 7

Transmits sensory information from the taste buds, through the internal acoustic canal, to the brain for the interpretation of taste
Also transmits motor impulses from the brain, through the internal acoustic canal to control the facial muscles and the lacrimal gland of the eyes

Sensory origin: taste buds
Motor Origin: pons
Sensory termination: Thalamus

Question 8

Vestibulocochlear Nerve (VIII)

Answer 8

Transmits sensory information from the eyes, through the optic canals to the occipital lobe of the brain for the interpretation of vision
Passage: internal acoustic meatus
Origin: cochlea, vestibule apparatus
Termination: medulla oblongata and pons

Question 9

Glossopharyngeal Nerve (IX)

Answer 9

Transmits sensory information from the tongue, through the jugular foramen, to the brain for the interpretation of pain
Also transmits motor impulses from the brain, through the jugular foramen, to control the muscles involved in swallowing

Sensory function: sensation of tongue and blood pressure
Motor function: salivation (parotid), swallowing, gagging
Sensory origin: tongue, carotid artery
Motor origin and sensory termination: medulla oblongata
Passage: jugular foramen

Question 10

Vagus Nerve (X)

Answer 10

Transmits sensory information from the thoracic and abdominal organs, through the jugular foramen, to the brain for the interpretation of pain. For example: stomach ache, appendicitis, etc.
Also transmits motor impulses from the brain, through the jugular foramen, to the thoracic and abdominal organs. For example: slows the heart rate. This is known as the vagal response.
Sensory function: thoracic abdominal viscera. Hunger, full, stomach ache
Motor function: swallowing, speech, regulation of viscera
Passage: jugular foramen
Motor termination and sensory origin: Thoracic, abdominal viscera
Motor origin and sensory termination: medulla oblongata

Question 11

Spinal Accessory Nerve (XI)

Answer 11

Transmits motor impulses from the spinal cord, through the jugular foramen, to control some upper-back and neck muscles
Function: head, neck, and shoulder movement
Origin: spinal cord and medulla oblongata
Termination: pharynx, trapezius, sternocleaidomastoid
Passage: jugular foramen

Question 12

Hypoglossal Nerve (XII)

Answer 12

Transmits motor impulses from the spinal cord, through the hypoglossal canal (foramen) to control the movement of the tongue