Page 1924 - Saunders Comprehensive Review For NCLEX-RN

CHAPTER 56

Eye and Ear Problems

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Priority Concepts
Safety, Sensory Perception

I. Anatomy and Physiology of the Eye
A. The eye
1. The eye is 1 inch (2.5 cm) in diameter and is located in
the anterior portion of the orbit.
2. The orbit is the bony structure of the skull that
surrounds the eye and offers protection to the eye.
B. Layers of the eye
1. External layer
a. The fibrous coat that supports the eye
b. Contains the cornea, the dense
transparent outer layer
c. Contains the sclera, the fibrous “white
of the eye”
2. Middle layer
a. Called the uveal tract
b. Consists of the choroid, ciliary body,
and iris
c. The choroid is the dark brown
membrane located between the sclera
and the retina that has dark
pigmentation to prevent light from
reflecting internally.
d. The choroid lines most of the sclera and
is attached to the retina but can detach
easily from the sclera.
e. The choroid contains many blood
vessels and supplies nutrients to the
retina.
f. The ciliary body connects the choroid
with the iris and secretes aqueous
humor that helps give the eye its
shape; the muscles of the ciliary body
control the thickness of the lens.
g. The iris is the colored portion of the

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