explain the structure of human ear?
Answers
The ear has external, middle, and inner portions. The outer ear is called the pinna and is made of ridged cartilage covered by skin. Sound funnels through the pinna into the external auditory canal, a short tube that ends at the eardrum (tympanic membrane).
Sound causes the eardrum and its tiny attached bones in the middle portion of the ear to vibrate, and the vibrations are conducted to the nearby cochlea. The spiral-shaped cochlea is part of the inner ear; it transforms sound into nerve impulses that travel to the brain.
The fluid-filled semicircular canals (labyrinth) attach to the cochlea and nerves in the inner ear. They send information on balance and head position to the brain. The eustachian (auditory) tube drains fluid from the middle ear into the throat (pharynx) behind the nose.
Structure of Human Ear
There are three parts of ear – the outer ear, middle ear and the inner ear. The outer ear consists of pinna and ear canal. The middle ear consists of the eardrum and the three ossicles. The inner ear includes semicircular canals that are connected to cochlea and auditory system.
The compressions in the air reach the outer ear called pinna which directs the sound to travel through the ear canal to reach the ear drum or tympanic membrane. Due to these compressions, the membrane starts vibrating. This thin membrane vibrates and relaxes depending on the amplitude of compression in air. The vibration is then passed to three bones in the ear connected to the ear drum: hammer, anvil and stirrup and is amplified about 20 times than the actual vibration.
After the amplification by ear bones, this vibration is passed through the oval ear called cochlea. A liquid is present in the cochlea. When the vibrations are sent to this liquid, it creates waves and gets the electrical signal out of the cochlea. Now from cochlea it is sent to brain through the auditory nerve. Brain reads the electrical impulses and detects it as sound. We have an Eustachian tube at the bottom which connects the ear with the nasopharynx, a part of nose.