STRUCTURE AND FUNCTION OF EYE AND EAR

Structure and Function of Eye and Ear

Structure and Function of Eye and Ear

Structure and Functions of the Eye

The human eye works very similar to that of most vertebrates and some mollusks; call lens has a lens that is adjustable according to the distance, called a diaphragm pupil whose diameter is regulated by the iris and a sensitive tissue light which is the retina. Light enters through the pupil, through the lens and is projected onto the retina, which is transformed by photoreceptor cells called into nerve impulses that are passed through the optic nerve to the brain (U, R., Ng, Y. K., & Suri, 2008, Pp.2-9).

Its shape is approximately spherical diameter is 2.5 cm and is filled with a transparent gel called vitreous which fills the space between the retina and the lens.

Structure

The organ of vision consists of eyelids, eyeballs, the lacrimal apparatus and ocular muscles. The eyeball is about 25 mm in diameter and kept in position thanks to the extraocular muscles (Oyster, 1999, Pp.11-15).

The eye wall is made ??up of three layers (U, R., Ng, Y. K., & Suri, 2008, Pp.2-9):

The outer layer, which includes the sclera (thick, resistant and white) in the front and the transparent cornea.

The middle layer includes choroid, which contains many blood vessels, and connective tissue of the ciliary body and the iris.

The inner layer is called the retina, which are the cells sensitive to light (rods and cones), covered by an outer sheet of cuboidal epithelial cells containing melanin. Externally, rests on the choroid retina, internally, is in contact with the vitreous.

Structure and Functions of the Ear

There are three different sections of a human ear: the inner near, the outer ear and the middle ear. The function of outer ear is to capture the sound ...