15.3 Senses BSC2086

Identify the functions of the sclera. Select all that apply.

- Protects a point of attachment for the extrinsic eye muscles -Protects internal structures -Maintains the shape of the eye

Identify the components of the fibrous tunic. Select all that apply.

- Sclera - Cornea

The ciliary body is continuous with the choroid and consists of the ______.

- ciliary processes - ciliary ring

The ciliary body is continuous with the choroid and consists of the ______. Select all that apply.

- ciliary processes - ciliary ring

The neural layer of the retina contains photoreceptor cells called and .

- cones -rods

The chamber of the eye that is between the iris and the lens is the chamber. It is filled with humor.

-posterior -aqueous

Where is aqueous humor found? Select all that apply.

Anterior chamber Posterior chamber

Where is aqueous humor found? Select all that apply.

Anterior chamber & the Posterior chamber

Match the tunic to its components: Fibrous tunic Vascular tunic Nervous tunic Choroid and ciliary body Sclera and cornea Retina

Fibrous tunic - Sclera and cornea Nervous tunic - Retina Vascular tunic - Choroid and ciliary body

Which structure controls the size of the pupil?

Iris

How does the avascular cornea acquire oxygen? Oxygen diffuses from the atmosphere to the cornea. Oxygen diffuses from the capillaries in the iris to the cornea. The ciliary body provides oxygen to the cornea. Lysozyme in tears releases oxygen to nourish the cornea.

Oxygen diffuses from the atmosphere to the cornea.

Explain how the avascular cornea obtains oxygen and nutrients. The vitreous humor supplies nutrients to the cornea The iris supplies nutrients to the cornea Oxygen from the outside air

Oxygen from the outside air

Identify the muscles of the iris that control the diameter of the pupil. Select all that apply.

Sphincter pupillae Dilator pupillae

Name the intrinsic muscles of the eye. Select all that apply.

Sphincter pupillae Dilator pupillae

What controls the size of the pupil?

Sphincter pupillae Dilator pupillae

Describe the location of the lens.

The lens is suspended between the posterior chamber and vitreous chamber by suspensory ligaments.

The optic disc is called the ____ _____because it does not contain any photoreceptors and therefore does not respond to light.

blind spot

The melanin-containing portion of the vascular tunic associated with the sclera of the eye is called the

choroid

The ciliary ring and the ciliary processes make up the _____ body.

ciliary

The lens becomes more spherical when the ______ contract.

ciliary muscles

The avascular, transparent structure that refracts light as it enters the eye is the

cornea

The anterior chamber is between the iris and the ______ and is filled with ______ humor.

cornea, vitreous

Together the cornea and the sclera comprise the ______ tunic

fibrous

The point where light rays cross after passing through a concave lens is referred to as the _____ point.

focal

The portion of the retina with the greatest visual acuity is called the

fovea centralis

In normal near vision light is refracted ______ than in distant vision, thus the lens is ______.

more, rounded

The sphincter pupillae are innervated by ______ fibers that cause the iris to ______ the pupil.

parasympathetic, constrict

The chamber of the eye that is between the iris and the lens is the _____ chamber and it is filled with ______ humor

posterior, aqueous

Light rays bend or ______ as they pass through media of different densities.

refract

The nervous tunic of the eye is composed primarily of the ______.

retina

The white outer layer that protects the internal structures of the eye, maintains the shape of the eye, and provides an attachment point for the extrinsic muscles of the eye is the

sclera

The lens is connected to the ciliary processes by the ______.

suspensory ligaments

The dilator pupillae are innervated by ______ fibers that cause the iris to ______ the pupil.

sympathetic, dilate

The dilator pupillae and sphincter pupillae are also known as ______.

the intrinsic muscles of the eye

The three chambers of the eye are the anterior chamber, posterior chamber and the chamber.

vitreous

Identify the structural and functional characteristics of the cornea. Select all that apply.

Focuses light Refracts light Transparent Allows light to enter eye

The structure of the eye that determines the amount of light that enters the eye by controlling the size of the pupil is the ______ .

Iris

List the characteristics of the optic disk. Select all that apply.

It is also called the blind spot. It is where nerve processes exit the eye. Blood vessels enter the eye here.

Describe the structure of the lens. It is biconvex and opaque. It is transparent and biconvex. It is concave on the inner surface and transparent. It is transparent and biconcave.

It is transparent and biconvex

The retina forms the ____ tunic

Nervous

What is the function of the sphincter pupillae and dilator pupillae?

They control the size of the pupil

The image focused on the retina is _____.

inverted

Name the structure which is suspended between the posterior chamber and the vitreous chamber by suspensory ligaments.

lens

Contraction of the ciliary muscles will cause the ______.

lens to become more spherical

In normal distant vision light is refracted ______ than in near vision, thus the lens is ______.

less, flattened

The fovea centralis is found in the center of a yellow spot on the retina called the _____ lutea.

macula

Describe the structure of the retina.

The retina is composed of an outer pigmented layer and an inner neural layer.

What are the suspensory ligaments?

These ligaments connect the lens to the ciliary processes and assist in focusing light.

Describe the choroid of the eye.

The melanin-pigmented portion of the vascular tunic associated with the sclera