The facts about the ear are discussed here in terms of their uses, problems and their functions.
A pair of ears present on the sides of animals of most genre and species.
In some animals, ears are moveable at will but in others like humans, ears are not moveable.
The presence of strong muscles in the ear pinna is responsible for the movement in few animals like mammals. However, these muscles are slightly strong enough to control movement in higher animals like man.
He instead use hands to drive away any insects or irritation affecting the ear.
Facts about the ear
1. Bio-metric tool: Ear is one of the external tool to establish identity of a person like the finger print or iris of the eye etc. This fact was first discovered in 1893 by Bertillon. The external features of ear like ear lobes, presence of piercing, shape etc. are used for the bio-metric purposes. It is said to be unique in comparison to other bio metric traits, due to being less affected by age, unaffected by change in facial expressions and also not affected by facial make-up or ornaments that can cover its appearance.
4. Blood labyrinth barrier: This is the barrier similar to blood brain barrier which separates inner ear from systemic circulation. Due to this drugs taken by systemic route does not reach the inner ear leading to ineffective treatment in case of infections or diseases to the ear. Hence, ear treatment can include other routes of drug administrations.
5. Body balance:
Inner ear vestibular system is the key for the maintenance of balance of our body. It has 3 semi circular canal each helping in sensing one type of movement. First one helps in senses up-and-down movement. Second canal helps in sensing side-ward movements. The third canal helps in sensing the tilting movements. These canals have fluid and hair cells inside. During movement, the fluid and hair cells move and the hair cells send these signals to the brain through the acoustic nerve. Our brain uses this information to interpret where we are in space. We tend to get vomiting when this balance system is agitated or disturbed.
6. Hearing loss: With age there is loss of sensitivity to higher frequency. Deafness is caused due to infections, immune disorders, ototoxicity by drugs and antibiotics. The bacterial and viral infections are prime cause while amino-glycoside antibiotics damage hair cells.
7. Hearing: The energy of sound waves is converted into neuronal energy and a signal is conducted to the brain. When the sound waves reach tympanic membrane, a series of movements is set down which leads to waves in fluids of cochlea. This stimulates sensory cells which send auditory stimuli to brain.
8. Hearing frequency: Sound waves travel in the form of waves and show wave nature i.e. have both frequency and also wave length. Human ears can hear a sound frequency in the range of 20 to 20 K hertz.
9. Ear in fetus: A baby develops ears by 16th week and is able to hear. The ears erect out and stand on sides of the head at this period.