HEARING, SMELL AND TASTE

Receptors for two sensory modalities hearing and equilibrium are housed in the ear. The external ear funnels sound waves to the external auditory meatus. The ear tube is always closed but during swallowing, chewing and yawn it opens. The inner ear is made with two parts one within another. The parts are perilymph and endolymph. External ear, middle ear and inner ear is helpful for hearing the sounds. Sound waves can travels to the distance from stapes.In animals the smell sense is high because the olfactory receptors are located in a specialized portion of the nasal mucosa the yellowish-pigmented olfactory mucosa membrane. The axons of the receptors terminate among the dendrites in olfactory bulbs. Abnormalities of olfaction include anosmia, hyposmia and dysosmia.Taste bud is used to identify the taste of everything. There are four types of cells are made for each taste bud. They are basic cell and microrilli. In human, the taste bud is located in the mucosa of the epiglottis, palate, and pharynx and in the tongue.