Ear: Structure, Function & Diseases

The ear belongs to the sensory organs. With it, the sound and thus sound as well as noises are absorbed as acoustic perception. In addition, the ear serves as an organ of balance.

What is the ear?

Anatomical structure of the ear. The ear is used for hearing and maintaining balance. It is composed of the outer ear, the middle ear as well as the inner ear. In the auditory canal of the ear are glands, which constantly produce earwax. This greasy secretion has important protective functions for the ear. It prevents the sensitive skin in the ear canal from drying out. Furthermore, the earwax coats dust and dirt particles that have found their way into the ear. With the help of the wax, they can be transported towards the pinna and thus to the outer ear. The ear is also an organ that reacts sensitively to external influences. This can lead to the development of specific diseases, which can have a lasting effect on the person concerned. In case of complaints of the ear, the ear, nose and throat doctor is consulted.

Anatomy and structure

The human ear occurs as a pair and sits on the head. It is divided into three sections. The outer ear includes the earlobe, the pinna, and the external auditory canal. The middle ear is composed of the eardrum and the ossicles anvil, malleus as well as stapes. The so-called eustachian tube connects the middle ear with the nasopharynx. The cochlea and the labyrinth make up the inner ear. In these, sound is converted into impulses and the organ of balance is controlled. The labyrinth and cochlea are similar in structure. Thus, both are filled with a fluid and have hair cells. The small hairs extend into the fluid. They have a crucial function in triggering nerve impulses and for controlling the sense of balance.

Functions and tasks

Schmatic diagram showing the anatomy of the auditory pathway, Auditory System. Click to enlarge. The ear has important functions for the human body. The outer ear and middle ear are also called sound-conducting apparatuses. The name is based on their task of receiving sound waves from the environment and transmitting them to the inner ear. The inner ear has two functions. Accordingly, it can be divided into two functional areas. The cochlea has the actual organ for hearing. It is a sound sensing apparatus. With its help, the brain can process incoming sound waves. Humans can receive sound waves in the frequency range from 16 to 16,000 hertz. If the sound waves are above or below this, they are outside the hearing spectrum for humans. The hearing organ is particularly sensitive to any frequencies that are between 1,000 and 4,000 hertz. This is a range that is especially crucial for speech. The organ of balance, on the other hand, has nothing to do with the sense of hearing. However, it is also located in the inner ear and, together with the hearing organ, is referred to by scientists as the organum vestibulocochleare. With the help of the organ of balance in the ear, a person can register movement and position of the head as well as detect changes.

Diseases

The human ear is susceptible to different diseases, which are very specific to the affected area of this organ. The outer ear has a delicate skin in the ear canal. The pinna is particularly susceptible to infectious diseases involving fungi and bacteria. An ear infection often develops from this. If this is inadequately treated and spreads to the bone around the ear canal, a cholesteatoma may develop. This can only be treated surgically. However, suppuration and inflammation can also affect the middle ear. Otoscopy can be used to examine diseases of the ear or hearing (e.g. otitis externa), foreign bodies or parasitic infestations of the external auditory canal, and complaints of the eardrum. It is usually performed by the ENT physician as the first examination for hearing problems. As a result, excess pressure occasionally develops there, which expands the eardrum. This, in turn, triggers ear pain. The middle ear infection can also spread to the bones and even destroy them. This part of the ear can also be damaged by very large amounts of sound. This is called acoustic trauma. The most common diseases in the inner ear develop because of a blast trauma or constant exposure to noise. In the beginning, only the outer hair cells are damaged.Later, the damage also spreads to the inner hair cells. This leads to a lack of conversion of sound stimuli into nerve impulses, which is referred to as hearing loss. In the context of this, the well-known tinnitus also occurs. Viral infections such as measles, meningitis and mumps can also affect this inner area of the ear.

Typical and common diseases

  • Ear flow (otorrhea)
  • Otitis media
  • Ear canal inflammation
  • Mastoiditis
  • Ear furuncle