Question

Draw the structure of the human ear and label the following parts:
(i) Tympanum
(ii) Cochlea
(iii) Pinna
(iv) Malleus
(v) Semi-circular canals
(vi) Eustachian tube

Answer 1

Hint: The human ear is considered as one of the most complex human organs. According to scientists and researchers, hearing is counted as one of the most complex of human senses. Hearing is considered as the ability of humans of perceiving different sounds by detection of vibrations travel through human ears. The ear turns these vibrations of sound waves into electrical signals which are then identified and interpreted by our brain.

Complete Answer:
The human ear is divided into the three parts namely, external ear, middle ear and inner ear. The tympanum and pinna are the parts of the external ear. Cochlea and semicircular canals are part of the inner ear. Malleus and Eustachian tubes are part of the middle ear.

Let us get familiar with the terms mentioned in the question which will help us to label them on the diagram.
(i) Tympanum: It is the part of external hearing in mammals, reptiles and birds. It plays a major role in the mechanism of hearing.
(ii) Cochlea: The organ of hearing or cochlea is one of the parts of the inner ear which comprises coiled tubes. It helps in converting sound vibrations to the perception of hearing.
(iii) Pinna: The pinna, a part of the external ear in humans, is also known as auricle. It is a shell-like part of the human ear. It is a cartilaginous structure and helps to amplify or say, detect and further direct the sound waves towards the auditory canal.
(iv) Malleus: It is the part of ear ossicle that is 3 tiny bones present in the middle ear. It has a shape of hammer and handle of it. It is attached to the inner side of the tympanic membrane.
(v) Semicircular canals: Semicircular canals are the part of inner ears. The canal has three fluid-filled tubes namely; anterior, posterior and lateral, which helps in keeping balance. When there is movement of head, these fluids sloshes and moves the hair around the canal. These hair send nerve impulses to the brain and the brain further passes messages to the body to stay balanced.
(vi) Eustachian tube: Eustachian tube is a narrow tube and it connects the middle ear with neck and throat. This part of our ear allows the entry of air into the middle ear. It also helps to drain mucus from the middle ear.

Given below is the diagram of human ears in which the said parts are labelled.

Note: It is a common misconception that sound waves traveling through air reach our ear and we are able to hear the sound. But, the vibrations of sound waves can reach our ears in two ways- air conduction or bone conduction. Air conduction hearing occurs when air carrying sound waves is picked up and then carried through different parts of ears such as pinna, tympanic membrane and so on. In bone conduction, the vibrations of sound waves are picked up by the inner ear. The air conduction hearing is always better as compared to that of bone conduction.