Cranial nerves

Cranial nerve disease is an impaired functioning of one of the twelve cranial nerves.

The olfactory nerve (Latin: nervus olfactorius) is typically considered the first cranial nerve, or simply CN I.

The trochlear nerve, also called the fourth cranial nerve or cranial nerve IV, is a motor nerve (a somatic efferent nerve) that innervates only a single muscle: the superior oblique muscle of the eye, which operates through the pulley-like trochlea.

The maxillary nerve (CN V2) is one of the three branches or divisions of the trigeminal nerve, the fifth (V) cranial nerve.

The recurrent laryngeal nerve (RLN) is a branch of the vagus nerve (cranial nerve X) that supplies all the intrinsic muscles of the larynx, with the exception of the cricothyroid muscles.

Bulbar palsy refers to impairment of function of the cranial nerves IX, X, XI and XII, which occurs due to a lower motor neuron lesion either at nuclear or fascicular level in the medulla oblongata or from lesions of the lower cranial nerves outside the brainstem.

The accessory nerve is a cranial nerve that controls the sternocleidomastoid and trapezius muscles.

The hindbrain or rhombencephalon is a developmental categorization of portions of the central nervous system in vertebrates.

The metencephalon is the embryonic part of the hindbrain that differentiates into the pons and the cerebellum.

The terminal nerve, or cranial nerve zero, was discovered by German scientist Gustav Fritsch in 1878 in the brains of sharks.

Injury to the spinal accessory nerve can cause an accessory nerve disorder or spinal accessory nerve palsy, which results in diminished or absent function of the sternocleidomastoid muscle and upper portion of the trapezius muscle.

Through studies of human embryos performed in the late 1890s, Swiss anatomist Wilhelm His identified a portion of hindbrain neuroepithelium that was distinct from the rest of the hindbrain neuroepithelium in its morphology, sustained chromosomal division into late stages of embryogenesis, and deployment of streams of neurons through the hindbrain periphery.