Accessory nerve | Cranial Nerve XI | Anatomy Tutorial скачать в хорошем качестве

Accessory nerve | Cranial Nerve XI | Anatomy Tutorial

#accessory #cranialnerve #vagusnerve Link for Donations https://paypal.me/studentlamedicina?l...   / anatomy.knowledge   The accessory nerve is the 11th cranial nerve and is purely motor. It has two roots: a cranial root and a spinal root. Fibers of the spinal root of accessory nerve originate in the spinal accessory nucleus which is a cluster of neurons located in the lateral aspect of the anterior horn of the spinal cord, stretching from C1 to C5 spinal levels. Axons from these motor neurons emerge from the lateral part of spinal cord between the anterior root and posterior root of spinal nerve. The firbers then accend through vertebral canal to enter the skull by way of foramen magnum as the spinal root of accessory nerve. The motor neurons of The cranial root of accessory nerve are located in the nucleus ambiguus. The axons of these neurons emerge from the medulla just posterior to the olive. Both cranial and spinal roots of accessory nerve unite with each other to leave the skull by way of jugular foramen. Immediately after coming out of the cranial cavity, the two roots again separate. The cranial root joins the vagus nerve just below its inferior ganglion and is distributed through the branches of the vagus to the muscles of the palate (except tensor palati), muscles of pharynx(except stylopharyngeus), and muscles of larynx. The spinal root of accessory nerve after detaching from the cranial part of accessory nerve continues alone and heads backwards and downwards to supply two muscles in the neck: The sternocleidomastoid muscle and the trapezius muscle. The spinal root of accessory nerve after detaches from the the cranial part is regarded as the spinal accessory nerve.