The external ear consists of the auricle, the external auditory meatus and tympanic membrane. Auricle commonly called ear, is formed of elastic cartilage covered with skin. The external auditory meatus consists of two parts: cartilaginous and bony. The first one is a continuation of the auricular cartilage in the form of a groove open upward and to the back. The bony auditory meatus which constitutes two thirds of entire length of auditory meatus. Tympanic membrane or ear drum is located at the junctions of the external and middle ears. Its edge fits into the sulcus tympanicus at the end of external auditory meatus. The middle ear consists of the tympanic cavity and auditory tube through which it communicates with the nasopharynx. The tympanic cavity in the middle ear is situated in the base of temporal bone between the external auditory meatus and labyrinth. Six walls are distinguished in the tympanic cavity: 1) membranous wall, 2) labyrinthine wall, 3) mastoid, wall of tympanic cavity, 4) carotid, wall of the tympanic cavity, 5) the roof and 6) floor. There is also Eustachian tube lets the air pass from the pharynx into the tympanic cavity.
The vessels and nerves of external ear: The ear receives arterial blood from superficial temporal and posterior auricular arteries. Venous blood drains into the posterior auricular and posterior facial veins. External ear innervates by the auriculartemporal nerve.
The vessels and nerves of middle ear: The arteries arise mainly from the external carotid artery. Numerous vessels penetrate the tympanic cavity from its branches. The veins accompany the arteries and drain into the pharyngeal plexus. The lymphatic vessels of middle ear run partly into the nodes on the lateral wall of pharynx.