GLOSSOPHARYNGEAL NERVE Motor fibers These arise from the upper part of the nucleus ambiguus in the medulla, and supply the stylopharyngeus muscle Sensory fibers Taste fibers from the posterior third of the tongue General somatic afferent fibers (pain, temperature, and tactile sensation) from the posterior third of the tongue, tonsils, soft palate, tympanic membrane, and Eustachian. baroreceptive from the carotid body and the carotid sinus Parasympathetic fibers (parotid gland).

VAGUS NERVE motor fibers arise from the nucleus ambiguus, supply all striated muscles of the larynx and pharynx, except the stylopharyngeus sensory fibers carried general visceral sensory input from the larynx, pharynx, linings of the trachea, bronchi, heart, aortic arch, and abdominal viscera parasympathetic to smooth muscle and glands of the pharynx, larynx, and thoracic and abdominal viscera.

Clinical features Isolated lesions of the glossopharyngeal nerve are rare. It is more common to see combined lesions of the IX and X Patients with IX and X nerve lesions present with symptoms of hoarseness, dysphagia, and dyspnea.

SPINAL ACCESSORY NERVE Arising from the nucleus ambiguus in the medulla and from upper cervical segments. It supplies two muscles: the sternocleidomastoid and the trapezius

SPINAL ACCESSORY NERVE Nuclear lesions: syringomyelia/syringobulbia, motor neuron disease. Skull and foramen magnum (lesions involve IX, X, XI, and XII) and may also affect the medulla or upper cervical cord). neoplasms (meningiomas, dermoids) meningeal processes, and traumatic injuries. Jugular foramen lesions: (lesions involve IX, X, and XI) leptomeningeal process (infectious, carcinomatous, and inflammatory) Trauma Guillain–Barré syndrome In the neck: surgical procedures in the posterior triangle of the neck such as lymph node excision or biopsy (most common cause radiation therapy

Hypoglossal (XII) Cause: demyelinating disease, motor neuron disease, syringobulbia, Chiari malformation, tumor, arteriovenous malformation, hemorrhage, ischemia, inflammatory, and infectious conditions, Polio, TB, UMN LMN