The external ear

The external ear

The external and middle ear develop from the first two branchial arches. The external ear canal is 3 /uni00A0 cm in length; the outer two-thirds is cartilage and the inner third is bony . The skin on the lateral surface of the tympanic membrane is highly specialised and migrates outwards along the ear canal. As a result of this migration most people’s ears are self-cleaning. The external canal is richly innervated and the skin is tightly Ernst Reissner , 1824–1878, Professor of Anatomy at Dorpat and later at Breslau, Germany (now Wroc ł aw , Poland), described the vestibular membrane of the cochlea in 1851. bound down to the perichondrium so that swelling in this region results in severe pain. The lymphatics of the external ear drain to the retroauric - ular, parotid, retrophar yngeal and deep upper cervical lymph - nodes.

The facial nerve can be damaged by trauma and ear • disease Chronic ear disease can lead to intracranial sepsis • There are two types of hearing loss: conductive and • sensorineural The clinical features of sinus infection, its treatment and • potential complications The diagnosis and management of chronic rhinosinusitis • with and without nasal polyposis The common sinonasal tumours, their presentation, • investigation and principles of treatment

The external ear

The external and middle ear develop from the first two branchial arches. The external ear canal is 3 /uni00A0 cm in length; the outer two-thirds is cartilage and the inner third is bony . The skin on the lateral surface of the tympanic membrane is highly specialised and migrates outwards along the ear canal. As a result of this migration most people’s ears are self-cleaning. The external canal is richly innervated and the skin is tightly Ernst Reissner , 1824–1878, Professor of Anatomy at Dorpat and later at Breslau, Germany (now Wroc ł aw , Poland), described the vestibular membrane of the cochlea in 1851. bound down to the perichondrium so that swelling in this region results in severe pain. The lymphatics of the external ear drain to the retroauric - ular, parotid, retrophar yngeal and deep upper cervical lymph - nodes.

The facial nerve can be damaged by trauma and ear • disease Chronic ear disease can lead to intracranial sepsis • There are two types of hearing loss: conductive and • sensorineural The clinical features of sinus infection, its treatment and • potential complications The diagnosis and management of chronic rhinosinusitis • with and without nasal polyposis The common sinonasal tumours, their presentation, • investigation and principles of treatment