The nucleus ambiguus is a cranial nerve nucleus, located in the medulla oblongata, and handles the branchial motor functions of the ninth (glossopharyngeal) and tenth (vagus) cranial nerves. The motor functions involved are many of the processes needed in swallowing.

Stylopharyngeus, a muscle, supplied by the glossopharyngeal nerve, is important in swallowing.

The muscles supplied by the vagus (included with this is the cranial part of the accessory nerve), such as levator veli palatini, are also necessary to swallow properly. The vagus also supplies the upper part of the oesophagus, and other parts of the pharynx and larynx.

As well as motor functions, nucleus ambiguus also contains the preganglionic neurons for the heart.

Anatomy

The nucleus ambiguus extends the whole length of the medulla, and sits just dorsal to the inferior olivary nucleus. It is not that easy to see in a stained section, which may explain its name.

External links

• Medical Neurosciences (http://128.104.8.64/virtualbrain/BrainStem/09NA.html) discuss the nucleus ambiguus.