5. The facial nerve supplies the muscles of the face.
6. The hyperglossal supplies the muscles of the tongue.
IV.—Mixed nerves:
1. The pneumogastric supplies lungs, heart, stomach, larynx, etc.
2. The spinal accessory supplies some muscles of the back.
The average weight of the brain in the adult male is about 49½ ounces, a little more than three pounds avoirdupois; in the female 44 ounces; the average difference between the two being from 5 to 6 ounces.
The spinal cord has a length of about 16 to 17 inches, and weighs about 1½ ounces.
The spinal cord is a continuation of the medulla oblongata, is lodged in the spinal canal, and gives off 31 pairs of nerves, that supply all the muscles of the body with sensitive and motor nerves.
The medulla oblongata is pyramidal in form, having its broad extremity upwards. It is expanded laterally at its upper part. Its length from the pons varolii to the lower extremity of the pyramid is about an inch and a quarter; its greatest breadth is nearly an inch; and its thickness from before backwards is about three-quarters of an inch.
The medulla is the link between the brain and the spinal cord. The majority of centers for various organic functions are situated in it; as follows: