Cranial Nerves V and VII-XII and Special Sensory Tests

Vocabulary flashcards covering the anatomical structures, innervation, pathologies, and clinical evaluation tests for Cranial Nerves V and VII through XII, as well as special sensory testing procedures.

Cranial Nerve V (Trigeminal Nerve)

The largest cranial nerve by diameter; provides main sensory innervation for the face (touch, temperature, and pain) and motor innervation via its third division to the muscles of mastication.

Trigeminal Nerve Sensory Divisions

The three divisions of CN V: V1 Ophthalmic (Sensory), V2 Maxillary (Sensory), and V3 Mandibular (Both sensory and motor).

Muscles of Mastication

The four muscles innervated by the motor fibers of CN V (division V3): temporalis, lateral pterygoid, medial pterygoid, and masseter.

Trigeminal Neuralgia (Tic Douloureux)

An inflammatory condition of CN V resulting in extreme, stabbing pain lasting a few seconds to a minute that can recur up to a hundred times per day, often triggered by light sensory stimuli like a breeze.

Face Brush Test

A clinical examination for CN V where a cotton wisp is brushed randomly across all three sensory divisions bilaterally while the patient's eyes are closed.

Cranial Nerve VII (Facial Nerve)

Cranial nerve providing motor innervation to muscles of facial expression, parasympathetic motor signals to lacrimal, nasal, palatine, and salivary glands, and taste sensation from the anterior 2/3 of the tongue.

Motor Branches of Cranial Nerve VII

The five motor branches of CN VII supplying the facial expression and scalp muscles: Temporal, Zygomatic, Buccal, Mandibular, and Cervical.

Bell's Palsy

Peripheral (LMN) facial nerve dysfunction caused by nerve inflammation, presenting with rapid-onset facial muscle paralysis, loss of forehead wrinkling, drooping lower eyelid, sagging corner of mouth, continuous tearing, and partial taste loss on the affected side.

Central Facial Nerve Palsy (Stroke)

An upper motor neuron (UMN) impairment resulting in difficulty smiling on the affected side while leaving the ability to wrinkle the forehead intact.

Smile and Forehead Wrinkle Test

A clinical test for CN VII where the patient is asked to give a big open smile and raise their eyebrows, allowing the clinician to differentiate between UMN stroke (forehead intact) and LMN Bell's Palsy (forehead impaired).

Cranial Nerve VIII (Vestibulocochlear Nerve)

Sensory nerve running from the inner ear to the pons that carries sensory information for equilibrium and hearing.

Branches of CN VIII

The two sensory divisions of CN VIII: the Vestibular branch (equilibrium) and the Cochlear branch (hearing).

Fingertip Moving Test

A CN VIII examination where rubbing fingers are moved laterally away from the patient's ear with eyes closed until the sound is no longer heard, comparing bilateral equal distances.

Cranial Nerve IX (Glossopharyngeal Nerve)

Cranial nerve providing motor control to part of the tongue and pharynx, parasympathetic input to parotid salivary glands, and taste plus general sensation from the pharynx and posterior 1/3 of the tongue.

Cranial Nerve X (Vagus Nerve)

The longest cranial nerve, providing motor signals to the pharynx and larynx, and parasympathetic signals to the heart, lungs, and abdominal viscera.

Ah Test

A joint clinical test for CN IX and CN X evaluating swallowing function, uvula elevation, and checking for hoarseness when the patient opens their mouth and says 'ah'.

Cranial Nerve XI (Accessory Nerve)

The only cranial nerve that does not originate in the brain stem; forms from nerve rootlets in the superior cervical spine ($C_1-C_5$) and provides motor supply to the trapezius and sternocleidomastoid muscles.

Shoulder Elevation Test

A physical assessment for CN XI in which the patient elevates their shoulders against downward resistance provided by the examiner.

Cranial Nerve XII (Hypoglossal Nerve)

Cranial nerve traveling from the medulla to supply motor innervation to both the intrinsic and extrinsic muscles of the tongue.

Stick Out Tongue Test

A assessment for CN XII function where the patient extends their tongue to check for inability to extend (bilateral damage) or side deviation (unilateral damage).

Sharp vs Dull Sensory Test

A special sensory evaluation where sharp and dull stimuli are randomly applied at three points from distal to proximal along a dermatome with the patient's eyes closed.

Vibration Sensory Test

A sensory test where a vibrating stimulus is applied at three distal-to-proximal points along a dermatome to check if the patient can perceive vibration with eyes closed.

Joint Position Sense Test

A proprioceptive test where three fingers are moved up or down while held strictly by their sides to see if the blindfolded patient can correctly identify movement direction.