Anatomy & Physiology of the Eye

The eye is complex.  The white of the eye is called the Sclera.  Muscles are attached to this that move the eye and keep its shape, called the extraocular muscles.  The cornea is the front 6th of the sclera.  All light passes through the cornea.

The second layer of the eye contains blood vessels that supply blood to the structures of the eye.

 The front part of the choroids (The dark-brown vascular coat of the eye between the sclera and the retina) contains 2 structures.  The ciliary body which is a muscular area that is attached to the lens used for focusing. 

The iris is the coloured part of the eye most commonly blue or brown.

The retina is the inner most area which is light sensing portion.  This contains a chemical called rhodopsin which converts light into electrical impulses that the brain interprets as vision.  These are carried by the optic nerve to the brain.

The eye lid is to protect the eye by blinking.  Eyelashes and eyebrows protect the eye from particles such as dust that could injure or irritate.

The Meibomian gland is responsible for producing oil and to lubricate the tear ducts.

The Structure Of The Hair Bulb – 

Keratin is a  protein which forms hair

The Cuticle is the outermost part of the hair shaft

The Cortex is the middle layer of the hair

The Medulla is the inner most layer of the hair shaft

The Inner Root Sheath is located between the outer root sheath and the hair shaft.  It is made up of 3 layers, Henle’s Layer, Huxleys Layer, and the cuticle.

The Outer Root Sheath encloses the inner root sheath and hair shaft.

The Connective Tissue is a form of fibrous tissue. Collagen is the main protein of connective tissue. 

The Dermal Papillae nourishes all the hair follicles and brings food and oxygen to the lower layers of epidermal cells.