the eye chapter 12 parts

Eyeball Layers

The eyeball is made of the sclera, choroid, and retina, from superficial to deep.

Sclera

The outer layer of the eyeball that contains the cornea and helps refract light rays into the eye.

Choroid

The middle layer of the eye which contains the ciliary body, iris, and pupil; the iris is the colored part that includes smooth muscle.

Retina

The inner layer of the eye containing the aqueous humor, cones, rods, fovea centralis, macula lutea, optic disk, and retinal blood vessels.

Fovea Centralis

Located in the middle of the macula lutea, it has the highest concentration of photoreceptor cells.

Optic Disk

The point where blood vessels enter the eye, resulting in a blind spot.

Oblique and Rectus Muscles

Muscles that control eye movement; oblique muscles pull at a slant, while rectus muscles pull straight.

Cilia/Eyelashes

Provide protection to the eye.

Conjunctiva

A mucous membrane lining under each eyelid and the anterior surface of the eyeball.

Lacrimal Apparatus

Contains tears, lacrimal ducts, and glands; the lacrimal gland produces tears.

What is the function of the sclera in the eye?

It contains the cornea and refracts light rays into the eye.

What does the iris do?

It is the colored portion of the eye that contains smooth muscle.

What is the role of the fovea centralis?

It has the highest concentration of photoreceptor cells, allowing for sharp vision.

What structure results in the blind spot of the eye?

The optic disk is where blood vessels enter the eye, creating the blind spot.

Fill in the blank: The outer layer of the eyeball is known as the __________.

Sclera.

Fill in the blank: The __________ is the colored part of the eye that contains smooth muscle.

Iris.

Fill in the blank: The __________ contains tears and drains fluid into the nasolacrimal cavity.

Lacrimal apparatus.