Chapter 15

Identify the structures that tears flow through, beginning with the structure that produces the tears. IN ORDER

1.) Lacrimal Gland 2.)Lacrimal Ducts 3.) Surface of the eye 4.)Lacrimal Canaliculi 5.)Nasolacrimal Duct 6.) Nasal Cavity

What is glaucoma?

A condition characterized by an abnormal intraocular pressure

What is a tastant?

A substance dissolved in saliva that causes taste cells to depolarize

Identify the changes that occur to the special senses because of aging. Select all that apply.

Ability to identify specific odors decreases Decreases sensitivity to gravity

Vascular tunic

Choroid and ciliary body

Eyelids

Lubricates eyeball by spreading tears over surface of the eye and protects eye from foreign objects

Name the small yellow spot found near the center of the posterior retina.

Macula

Extrinsic eye muscles

Moves the eyeballs

Conjunctiva

Mucus membrane protecting inner surface of eyelid and anterior surface of sclera

A concave lens corrects ______.

Myopia

People who have ______ can see close object clearly, but distant object appear blurry.

Myopia

The retina forms the ________ tunic.

Nervous

Place the tunics of the eyeball in order, beginning with the innermost layer.

Nervous Tunic Vascular Tunic Fibrous Tunic

Most neurons are permanent cells, however __________ neurons are unique among sensory neurons in that they are continuously replaced.

Olfactory

Most neurons are permanent cells, however _____ are neurons that are constantly being replaced.

Olfactory neurons

Identify the structural and functional characteristics of the cornea.

Transparent Focuses light Refracts light Allows light to enter eye

Olfactory neurons are located in the olfactory epithelium of the superior region of the nasal cavity

True

The _________ membrane is a thin, semitransparent membrane that separates the external ear from the middle ear.

Tympanic

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

ciliary processes ciliary ring

The part of the cochlea located between the vestibular membrane and the basilar membrane is the ______, and it is filled with ______.

cochlear duct, endolymph

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

cones and rods

An inflammation of the thin, transparent mucous membrane covering the inner eyelid and the sclera is called pinkeye or __________

conjunctivitis

In distant vision, the lens is ______ than in near vision.

flatter

People who have ______ can see distant object clearly, but close object appear blurry.

hyperopia

Accomidation occurs when the _________.

lens changes shape

Contraction of the ciliary muscles will cause the ______.

lens to become more spherical

Presbyopia occurs when the lens becomes ______.

less flexible

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

less, flattened

The ______ layer of the retina is dark in order to enhance visual acuity by reducing light scattering and the ______ layer of the retina converts light into action potentials.

pigmented, neural

The photoreceptive molecule of rods is ______ and the photoreceptive molecule of cones is _____.

rhodopsin, iodopsin

During near vision, the lens is ______ and during distant vision the lens is ______.

rounded, flattened

the lens is connected to the ciliary processes by the _________

suspensory ligaments

The auditory ossicles function in transmitting vibrations from the ______ to the ______ of the inner ear.

tympanic membrane, oval window

The interior eye chamber that is almost completely surrounded by the retina and is filled with vitreous humor is the _______ chamber.

vitreous

What are rods?

Bipolar photoreceptors that play a role in non-color vision under low light conditions

What do taste cells and olfactory cells have in common?

Both are sensory cells. Both are replaced continuously.

Identify the structures within the external auditory canal that prevents foreign objects from reaching the tympanic membrane.

Cerumen Hair

Starting with a photoreceptor cell indicate the pathway of signal conduction.

Cone cell bipolar ganglion cell optic disc optic nerve

List 3 mechanisms which allow the eye to focus on objects located closer than 20 feet.

Convergence of the eyes Accommodation by the lens Constriction of the pupil

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

Cornea

The anterior chamber is between the iris and the _______ and is filled with _______ Humor

Cornea Aqueous

The term that describes the greatest distance through which an object can be moved and still remain in focus is ________of_________.

Depth of Focus

The greatest distance through which an object can be moved and still remain in focus is ______.

Depth of focus

Which of the following correctly differentiates endolymph and perilymph? Select all that apply.

Endolymph is within the membranous labyrinth and perilymph is between the membranous labyrinth and the bony labyrinth. Endolymph has a high concentration of potassium and a low concentration of sodium compared to perilymph

List the structures of the visual system

Eye Lacrimal gland

True or false: Images focused on the retina are right side up.

False

Identify the outermost layer of the wall of the eyeball.

Fibrous Tunic

Identify the structures within the external auditory canal that prevents foreign objects from reaching the tympanic membrane. Select all that apply.

Hair Cerumen

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

Where would you find rods and cones?

In the neural layer of the retina

Where are olfactory neurons located?

In the superior nasal cavity

Which structure controls the size of the pupil?

Iris

List the characteristics of the optic disk.

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

Explain how the avascular cornea obtains oxygen and nutrients.

Oxygen from the outside air

The projections on the surface of the tongue that contain taste buds are called __________.

Papillae

Place the cells of the retina in the order that action potentials will pass towards the optic nerve.

Photoreceptor bipolar ceill ganglion cell

What is the normal unavoidable degeneration of the accommodation power of eye associated with aging called?

Presbyopia

Eyebrows

Prevents perspiration from entering the eyes and shades the eyes from sunlight

What are papillae?

Projections on the surface of the tongue

Lacrimal apparatus

Protects and lubricates the eyes through the production of tears

Identify the functions of the sclera.

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

Tears originate in the lacrimal glands. Name the other structures they flow through.

Punctum Lacrimal sac Lacrimal canaliculi Lacrimal papilla

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

Refract

Nervous Tunic

Retina

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

Retina

Under low light conditions the photoreceptors cells which are responsible for vision are the ___________.

Rods

Differentiate rods and cones.

Rods contain the photoreceptive molecule rhodopsin and cones contain the photoreceptive molecule iodopsin.

The ________ window dissipates sound waves to protect the inner ear from a buildup of pressure.

Round

Identify the structure that dissipates sound waves to protect the inner ear from the buildup of pressure.

Round window

Identify the structure labeled A in this picture of the inner ear.

Scala vestibuli

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 5 major tastants are salt,_____,_____,________, and ________.

Sour, Sweet, Bitter, Savory

Substances dissolved in saliva that cause the depolarization of taste cells are called

Tastants

Name sensory cells that are continuously replaced.

Taste cells Olfactory cells

What are the olfactory vesicles?

The bulbous enlargement of the olfactory neuron dendrite.

What is vitreous humor?

The jelly-like substance found in the vitreous chamber

Describe the location of the retina

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

Describe the choroid of the eye.

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

What are the suspensory ligaments?

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

Photoreceptor cells synapse with ______ cells which in turn synapse with ______ cells.

bipolar, ganglion

Earwax is also called _____.

cerumen

When you leave a darkened movie theater and walk into the bright sunlight your eyes undergo several changes. This is known as ______.

light and dark adaptation

The membranous tunnel within the bony labyrinth of the inner ear is the __________ _________.

membranous labyrinth

The part of the cochlea located above the spiral lamina and the vestibular membrane is the ______ and It is filled with ______.

scala vestibuli, perilymph

Fibrous tunic

sclera and cornea

A condition in which the cornea or lens is not uniformly curved is called ______.

astigmatism

Describe the structure of the lens.

It is transparent and biconvex.

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

Lens

Name the bulbous enlargement of the olfactory neuron dendrites.

Olfactory vesicles

The area of the retina that does not respond to light is the ______.

Optic Disc

Select all of the structures that play a role in conducting signal from a photoreceptor cell to the brain.

Optic nerve Ganglion cells Bipolar cells

Select the structures through which sound waves will travel from the outer ear to the inner ear. Select all that apply.

Oval window Spiral organ Tympanic membrane

How does the avascular cornea acquire oxygen?

Oxygen diffuses from the atmosphere to the cornea.

Identify the structure that separates the external ear from the middle ear.

Tympanic membrane

The jelly-like substance found in the largest chamber of the eye is called _____.

Vitreous Humor