Physiology of the ear and wax production
The ear is the organ of hearing & balance, and is functionally divided into three parts:
- The outer ear, consisting of the auricle or pinna and external auditory canal.
- The middle ear is composed of the tympanic membrane, which forms the border between the outer and middle ear, and three small bones (osscles); the malleus, incus and stapes
- The inner ear contains different sensory cells that are essential for the detection of sound and vibration and are responsible for our hearing (cochlea) and balance (vestibular system).
The Pinna or auricle
The Pinna or auricle is the outside part of the ear. The skin of the pinna contains a number of sebaceous (oil) glands and fine hairs and continues with the lining of the external auditory canal. It has several ridges and depressions, which contribute towards its function to collect and direct the sounds towards the ear canal, and helping with sound localisation.
External auditory canal or tube
This is the tube that connects the outer ear to middle ear. The outer third of the canal is made of cartilage and has thick skin like the pinna (see figure). This part has a number of wax and sebaceous glands that secrete cerumen (wax & oil). The inner two thirds is the bony part lined with thin sensitive hairless skin, containing no glands.