Cranial nerves Flashcards
What are the names of the 12 cranial nerves?
Olfactory
Optic
Oculomotor
Trochlear
Trigeminal
Abducens
Facial
Vestibulocochlear
Glossopharyngeal
Vagus
Accessory
Hypoglossal
What is the first cranial nerve and its function?
Olfactory
Conveys sense of smell
What is the second cranial nerve and its function?
Optic
Transmits visual information (facilitates vision)
What is the third cranial nerve and its function?
Oculomotor
Controls eye movement and pupil constriction
What is the fourth cranial nerve and its function?
Trochlear
Controls eye movement
What is the fifth cranial nerve and its function?
Trigeminal
Controls the touch and pain sensations from the face and head
The trigeminal nerve also controls the muscles used for chewing
What is the sixth cranial nerve and its function?
Abducens
Controls eye movement
What is the seventh cranial nerve and its function?
Facial nerve
Controls taste on the front two-thirds of the tongue It also receives information from the ear and controls the muscles of facial expression
What is the eighth cranial nerve and its function?
Vestibulocochlear
Controls hearing and balance
What is the ninth cranial nerve and its function?
Glossopharyngeal
Controls some functions of swallowing as well as taste on the back third of the tongue It conducts information from the tongue, tonsils and pharynx
What is the tenth cranial nerve and its function?
Vagus
Controls heart rate, digestion, some of the action of swallowing, is involved in the sneeze and cough relfexes
What is the eleventh cranial nerve and its function?
Accessory
Controls the muscles of head movement
What is the twelfth cranial nerve and its function?
Hypoglossal
Controls the muscles of the tongue
Which four cranial nerves carry sympathetic fibres?
III, VII, IX and X
Which cranial nerves are motor cranial nerves?
CN III, IV, VI, XI and XII
Which cranial nerves have their nuclei of origin close to the midline of the brainstem?
III, IV, VI, XII
Which cranial nerve arises from the cervical spinal cord?
XI
Which cranial nerves are mixed nerves?
V, VII, IX, and X
What information does the mesencephalic nucleus of the trigeminal nerve process?
Proprioception from muscles of mastication
What is unique about the mesencephalic nucleus of the trigeminal nerve in comparison to the rest of the CNS?
Is the only site in the CNS where the cell bodies of the primary afferent neurons live inside the CNS
Where are the sensory nuclei of the trigeminal nerve found?
Stretching from midbrain down to upper 2 parts of cervical spinal cord
What are the functions of the vagus nerve?
- Tactile sense, pain and temperature sense from the pharynx, larynx, trachea, oesophagus and thoracic and abdominal viscera
- Taste (epiglottis)
- Parasympathetic innervation to ganglia serving thoracic and abdominal viscera
- Motor (striated muscle of the pharynx and larynx)
Which is the only cranial nerve which doesn’t exit the brainstem anteriorly?
IV
Which is the only sensory modality that doesn’t synapse in the thalamus prior to reaching the cortex?
The olfactory nerve
Which letter is the superior colliculus?
D
What is the most common cause of temporary loss of smell?
URTI
What can cause permanent loss of smell?
Frontal meningioma
Trauma (ethmoid bone)
Where does the olfactory nerve stem from?
Telencephalon
Where does the optic nerve stem from?
Dienchephalon
Where does the trigeminal nerve originate?
The middle cerebellar peduncle
Which cranial nerve emerges from the junction of the pons and the medulla?
Abducens
Which nerves are located at the cerebellopontine angle?
Facial nerve
Vestibulocochlear
