Eyeball, Ear, Smell, Taste

What are the general sensory functions of vision?

Touch, Vibration, Temperature, Pain

What are the two structures related to the eye?

Adnexa and Globe (eyeball)

What is the function of the nasolacrimal duct system?

drains the tear into nasal cavity.

What are the components of the tunica fibrosa?

Sclera (white part) and Cornea (clear part over the iris)

What are the components of the tunica vasculosa?

Iris, Ciliary body, and Choroid

Define the iris

regulates the amount of light entering the eye

Define Ciliary body

contains a ring of smooth muscle that surrounds the lens

What is the functions of the Cornea?

Clear and primary refractive index

Define retina

Contains photoreceptors cells

Define lacrimal glands

produce tears

Define pupil

Aperture allowing light to enter the eye

Define eyelid

protects the anterior part of the eye and disperse the tear film

Define optic nerve

arise from the ganglion cells

Define cornea

primary refractive media of the eye

Define extraocular muscles

voluntary movement of the eye

Define lens

helps the eye focus

In a “fight-or-flight” situation, which of the following physiological changes may be experienced?

1.) Dilation of the respiratory airways

2.) increased sweating

3.) increased heart rate and force of contraction

4.) dilation of peripheral blood vessels and in skeletal muscles

5.) all of the above

all of the above

What is the functions of the Sclera?

maintains your eye's shape and protects it from injuries

Define Choroid

The pigmented part of the eye's vascular layer that nourishes the retina with blood vessels.

What is the tunica nervosa?

The inner sensory layer which includes the retina

What is the primary function of the cornea?

Clear and primary refractive index

What is the function of the sclera?

Helps maintain your eye’s shape and protects it from injury

What functions does the tunica vasculosa perform?

Routes for blood vessels & lymphatic, regulates amount of light (iris), secretes aqueous humor (ciliary body), controls shape of lens (focusing - ciliary body + zonule fibers)

What are the segments of the eye?

Anterior segment (Anterior chamber, Posterior chamber), Posterior segment

What is the function of the lens?

bends the rays of light coming into the eye and focuses them on one point

What is accommodation in terms of vision?

The eye’s ability to adjust its focus to see objects clearly at different distances

What are the two layers of the retina?

Outer pigmented retina and inner neural retina

What are the types of photoreceptors?

Cones and rods

What do rods do?

Do NOT discriminate light colors, highly sensitive to light, and concentrated toward periphery

What do cones do?

Color vision, clear & sharp images, and concentrated in the fovea

What makes up the optic nerve?

Optic disc & cup and axons of ganglion cells

What is the function of the optic nerve?

convey electrical impulses to the occipital lobe

What is visible light?

Visible spectrum of light

What is refraction in terms of light?

Bending of light rays

What is visual acuity?

Clarity of vision

What is considered normal visual acuity?

20/20; clear vision

What does 20/40 visual acuity mean?

Can only view the object half the distance (10 feet)

What does 20/400 visual acuity mean?

Still have vision but can’t see an object only if it's right in front of them

What does no light perception (NLP) mean?

Blindness

What is hyperopia?

Can see far but not near, needs convex lens (farsightedness)

What is myopia?

Can see near but not far, image falls short in the retina (nearsightedness)

What is astigmatism?

Will never see clearly; unless with laser surgery

what is the focal length measured in?

Meters

What are some refractive errors?

Hyperopia, Myopia, Astigmatism

What is retinal detachment?

A thin layer of tissue (the retina) at the back of the eye pulls away from its normal position

What is glaucoma?

High pressure in the eye, could cause blindness

What is a cataract?

cloudy area in the lens of your eye; almost everyone after the age of 80

What is macular degeneration?

an eye disease that can blur your central vision; common in Caucasians

What is diabetic retinopathy?

a diabetes complication that affects the eyes; could lead to blindness

Focusing an object onto the retina is the responsibility of the

Lens

Which structure is involved in regulating the amount of light entering the eye?

Iris

Anatomically, all of the following structures are found in the outer ear EXCEPT the

1.) tympanic membrane

2.) auricle

3.) cochlea

4.) external auditory canal

cochlea

All the following are types of tastes EXCEPT

1.) sour

2.) umami

3.) bland

4.) sweet

bland

The primary refractive index (media) of the eye is the

Cornea

Which structure is involved in tear production?

lacrimal gland

Cones are most dense in the

fovea

The ear is divided into which three anatomical parts?

External ear, middle ear, inner ear

A visual acuity of 20/20 denotes

1.) non of the above

2.) refractive correction

3.) all the listed statements are associated with 20/20 vision

4.) the image falls on the retina

5.) “normal” vision

all the listed statements are associated with 20/20 vision

Taste buds are located primarily on the

tongue

Which cell gives rise to the optic nerve?

ganglion cells

Olfaction is dependent on ____ cells

olfactory

The inner ear consists of

cochlea, vestibule, and semicircular canals

The outer ear consists of

Tympanic membrane, auricle, and external auditory canal

The middle ear consists of

tensor tympani muscle, the ossicles, stapedius muscle, and pharyngotympanic (eustachian) tube

What segment of the cochlea contains the organ of Corti (spiral organ)?

The scala media

The Japanese word describing a savory taste is _____

umami

The two primary types of cholinergic receptors of the parasympathetic nervous system are ___ and ____ receptors

Muscarinic, nicotinic

The tunica fibrous would most likely include the

sclera

The sclera is continuous with a transparent layer over the anterior eye known as the:

cornea

Which structure is involved in regulating the amount of light entering the eye?

Iris

The innermost layer of the eyeball is the:

retina

Tear production is produced by the

lacrimal gland

what is Presbyopia?

gradual loss of your eyes' ability to focus on nearby objects, becomes noticeable in your early to mid-40s and continues to worsen until around age 65

What is the function of the external ear?

It receives sound waves.

What happens in the middle ear?

Sound waves are changed to mechanical vibrations.

What is the role of the inner ear?

Vibrations stimulate receptor cells, and it contains the vestibular organ that maintains balance and equilibrium.

What is the auricle made of?

Elastic cartilage covered by stratified squamous keratinized epithelium.

Describe the external auditory meatus.

A canal extending from the auricle to the tympanic membrane, kept patent by elastic cartilage and covered by thin skin.

What glands are present in the external auditory meatus?

Hairs, sebaceous glands, and ceruminous glands.

What is the tympanic membrane?

An oval membrane covered by thin skin externally and simple cuboidal internally, attached to the malleus.

What is tinnitus?

Ringing in the ears caused by irritative stimuli within the inner ear or the nerve itself.

What are the types of deafness?

Conduction deafness and nerve deafness.

How does the Weber test distinguish between types of deafness?

Sound is louder in the diseased ear in conduction deafness and louder in the normal ear in nerve deafness.

What is conduction deafness caused by?

Interference with sound transmission, such as foreign body, cerumen buildup, or otosclerosis.

What is nerve deafness caused by?

Issues in the inner ear or CN VIII, such as acoustic neuroma or CVA.

What are the two primary chemical senses in the human body?

Taste (gustation) and smell (olfaction).

Which type of receptors mediate the chemical senses?

Chemoreceptors.

How are gustation and olfaction perceived?

They are mediated differently but perceived together.

What additional receptors in the mouth participate in taste perception?

Cutaneous receptors that detect texture and temperature.

What is gustation?

A sensory mechanism mediated by chemoreceptors sensitive to dissolved organic and inorganic compounds.

Where are taste receptors located?

On the tongue, in the mouth, and in the pharynx.

What is ageusia?

Loss of taste.

Name the five primary taste qualities.

Sweet, bitter, salt, sour, and umami.

Which area of the tongue is most sensitive to sweet taste?

The tip of the tongue.

Which substance primarily produces a bitter taste?

Alkaloids, such as quinine or caffeine.

Where is the salt taste most sensitive on the tongue?

The front half of each side of the tongue.

What sensation is produced by acids, and where is it most sensitive on the tongue?

Sour taste; the back half of each side of the tongue.

What is umami, and what triggers this taste?

A taste of glutamate.

How is the threshold of taste defined?

The lowest concentration of an applied stimulus that can be discriminated.

What happens during the adaptation of taste?

Continuous application of a stimulus results in a decrease in the intensity of the stimulus until it becomes tasteless.