eye a&p: main structures + function

what is the anatomy of the eye?

hollow, fluid filled space

what are the 3 tissues in the wall of the eyeball

1. outer fibrous tunic

2. middle vascular tunic

3. inner nervous tunic

what are the components of the fibrous tunic?

sclera cornea

what is the sclera

firm white outer connective tissue layer

what are the functions of the sclera (3)

1. helps maintain the shape

2. protects internal structures

3. provides attachment sites of the extrinsic eye muscles

what is the cornea?

transparent part of the eye

what are the functions of the cornea (2)

1. permits light to enter

2. bends and refract the entering light

what are the components of the vascular tunic?

choroid ciliary body lens iris

what is the choroid?

thin structure that consists of a vascular network and melanin containing pigment cells

what is the function of the choroid?

absorb light to prevent reflection and interference with vision

what is the ciliary body? (2)

1. smooth muscles called ciliary muscles that is attached to the lens by suspensory ligaments

2. produces aqueous humor

what is the lens?

flexible biconvex transparent disc

what is the iris? (2)

1. coloured part of the eye

2. contractile structure consisting of smooth muscles surrounding an opening called the pupil

what are the functions of the iris? (4)

1. light passes through the pupil and the iris regulates the diameter of the pupil

2. controls the amount of light entering the eye

3. as light intensity increases pupil contracts

4. as light intensity decrease pupil dilate

what are the 3 chambers of the eye?

1. anterior

2. posterior

3. vitreous

what is the function of the eye? (3)

1. pupil allows light into eye which is focused by the cornea lens and humors onto the retina

2. light striking the photoreceptors of the retina produces action potential within the visual pathway

3. the optic nerve conveys these action potentials to the brain where perception occurs