Cranial Nerves & Their finctions

Cranial Nerve I (Olfactory Nerve)

Special sensory nerve responsible for smell; originates in the olfactory epithelium and passes through the cribriform plate of the ethmoid bone.

Cranial Nerve II (Optic Nerve)

Special sensory nerve for vision; originates in the retina and passes through the optic canals of the sphenoid bone to the diencephalon via the optic chiasm.

Cranial Nerve III (Oculomotor Nerve)

Motor nerve originating in the midbrain that controls eye movements, including the superior, inferior, and medial rectus muscles.

Cranial Nerve IV (Trochlear Nerve)

Motor nerve responsible for eye movement.

Cranial Nerve V (Trigeminal Nerve)

Mixed sensory and motor nerve for the face; divided into V1 (Ophthalmic), V2 (Maxillary), and V3 (Mandibular) branches.

Cranial Nerve VI (Abducens Nerve)

Motor nerve responsible for eye movement.

Cranial Nerve VII (Facial Nerve)

Mixed nerve controlling facial expressions, lacrimal and salivary glands, and taste from the anterior two-thirds of the tongue.

Cranial Nerve VIII (Vestibulocochlear Nerve)

Special sensory nerve responsible for hearing and balance; passes through the internal acoustic meatus of the temporal bone.

Cranial Nerve IX (Glossopharyngeal Nerve)

Mixed sensory and motor nerve involved in taste from the posterior one-third of the tongue and functions in the head and neck.

Cranial Nerve X (Vagus Nerve)

Mixed nerve with wide visceral distribution in the thorax and abdomen, regulating autonomic functions; passes through the jugular foramen.

Cranial Nerve XI (Accessory Nerve)

Motor nerve providing innervation to neck and upper back muscles.

Cranial Nerve XII (Hypoglossal Nerve)

Motor nerve responsible for tongue movements.

Bell's Palsy

Condition characterized by unilateral facial muscle paralysis resulting from inflammation of the facial nerve (CN VII).

Neuromuscular Junction

The interface between motor neurons and muscle fibers where acetylcholine receptors play a key role in muscle contraction.

Resting Membrane Potential

The differential ion concentration across a cell membrane that determines cellular excitability.