Anatomy Final Exam Extra Credit (Ch. 15)

What are the “5 senses”?

• Sight

• Taste

• Smell

• Hearing

• Touch

What is the 6th sense?

Balance/equilibrium

The special senses (all but touch) contain distinct ______ modified to be special receptors

Sensory cells

About 70% of the sensory receptors in the body are in the ____

eyes

About 50% of the cerebral cortex is involved in _______

visual perception

Vision requires a ___________ reaction - a change in chemical structure caused by light energy

photochemical

Vision is our _____ sense, and is the perception of objects in the environment by means of the ____ they emit or reflect

dominant; light

Lacrimal Gland

Lacrimal Sac

Lacrimal Duct

_________ protect the eye and aid eye function

accessory structures

What are the 5 accessory structures of the eye?

• Eyebrows (protection and shade)

• Eyelids (protection)

• Conjunctiva (lubricating mucous production)

• Lacrimal apparatus (team production and spread)

  • Extrinsic eye muscles (eye movement)

Your nose runs when you cry because your tears exit through the _____.

nose

There are _____ pairs of ocular muscles that control the eye

6

Strabismus (cross-eyed) is caused from _________.

weakness in ocular muscles.

90% of people aged 55+ have eyelash _____.

mites

The eye ____ and ____ separate the eye into

lens and ciliary zonule

the eye is a ________, _______ hollow sphere

slightly irregular, fluid filled

What are the 3 layers (tunics) of the eye?

fibrous, vascular, and inner sensory layer

The fibrous layer of the eye has 2 regions. The _____ and ______

sclera and cornea

The lens is _____, transparent, and ______.

biconvex; flexible

What are the 4 characteristics of the sclera?

• opaque posterior region

• protects and shapes eyeball

• Anchors extrinsic eye muscles

• posteriorly, where optic nerve exits, sclera is continuous with dura mater of brain

What are the 3 characteristics of the cornea?

• Transparent anterior one-sixth of fibrous layer (forms clear window to let light enter and bends light as it enters)

• Epithelium covers both surfaces (outer surface protects from abrasions, inner contains sodium pumps to maintain clarity)

• Numerous pain receptors for blinking and tears

what are the 3 regions of the eye’s vascular layer?

• Choroid

• ciliary body

• iris

what are the 3 characteristics of the choroid region?

• Posterior portion of uvea

• supplies blood to all layers of eyeball

  • Brown pigment absorbs lite to prevent light scattering, which would cause visual confusion

What is the function of the ciliary body?

to hold the lens in place

The iris is the colored part of the eye that lies between the _____ and _____, continuous with ciliary body.

cornea and lens

The pupil is the central opening that _______ the amount of light entering

regulates

close vision and bright light causes the sphincter pupillae (circular muscles) to contract and pupils _____. Parasympathetic control

constrict

Distant vision and dim light cause dilator pupillae (radial muscles) to contract and pupils to _____. Sympathetic control

dilate

Changes in emotional state, like when subject matter is appealing or requires problem solving skills, cause pupils to ______.

dilate

The inner layer (retina) contains what 3 things?

• millions of photoreceptor cells that transduce light energy

• neurons

  • glial cells

The optic disc is the site where the ______ leaves the eye, lacks photoreceptors, so it is referred to as a ______.

optic nerve; blind spot

The retina has a quarter billion photo receptors that are in one of 2 types, ____ and _____.

Rods and cones.

Signal output travels the _______ direction of light in the eye

opposite.

Rods in the eye see ___ and are your ____

dim light, peripheral vision receptors.

Rods are _____ and ______ to light than cones

more numerous, more sensitive

Rods lack ______ but have their numbers greatest in the ______ vision

color vision; peripheral

Cones are vision receptors for _____ and have ________.

bright light; high-resolution color vision.

The fovea centralis is a tiny pit in the center of the macula lutea that contains all ____.

cones

Diabetic retinopathy causes _____ in vision due to damaged blood vessels

dark spots

Glaucoma causes blindness due to lack of _________ drainage, putting pressure on the retina and optic nerve

aqueous humor

Cataracts occur when _____ precipitates on the lens, clouding vision

protein

Chemical senses are ______ and _____

olfaction (smell) and gustation (taste)

The chemoreceptors respond to chemicals in _____ and are complimentary

aqueous solution

in smell, substances are dissolved in _____.

mucus

In taste, substances are dissolved in _____.

saliva

Smell is the ______ sense to develop in the embryo

first

An infant can recognize their mother by _____ old

7 days

Smell acts as an ________ for things like bad food, chemical fumes, fire.

early warning system

Smell has a _____ factor in taste

strong

smell can trigger _____ and may have a role in ______.

memories; reproduction.

olfactory receptor cells are specialized _______.

bipolar neurons

olfactory cells are the ____ cells able to reproduce every 60 days

only

mucus captures ______ substances for detection

inhaled

Naegleria fowleri can follow ______ to the brain and can cause death.

olfactory nerves

there are about ______ tastebuds on the tung, in peg like papillae

10,000

different types of papillae may have different ____, but all contain tastebuds

shapes

all parts of the tounge can taste _____ taste sensations

ALL

what are the 5 basic taste sensations?

-sweet - (sugar)

-Salt - (metal ions)

Sour - (hydrogen ions, acids)

Bitter - (alkaloids)

Umami (savory, elicited by the amino acid glutamate)

To be tasted, what must happen to a chemical

Dissolved in saliva → Diffuses into taste bud pore → Touches gustatory hair → Release of synaptic vesicle contents from gustatory cell, triggering a nerve signal

Adaptation of a taste occurs within __ to __ minutes, which is why food tastes best when you start eating.

1-5

what is the pathway for taste?

Taste buds → Medulla oblongata → Thalamus, hypothalamus and limbic system (appreciation of taste) → Gustatory cortex (recognition of taste)

Taste triggers the hypothalamus to trigger what 3 things?

• salivation

• Stomach secretions/motility

• If foul or rancid food - vomiting center

Taste is ___ smell

80%

________ is the feeling when something that is though to be tasted is actually just smelled.

Retronasal olfaction

Aroma _____ taste

enhances

Nasal congestion _____ taste.

decreases

sound is an audible _____ of molecules

vibration

Sound can be transmitted through ____, ____, and ____, but not ____.

Water, Solids, Air; But not a vacuum.

The _______ vibrates and moves the ossicles

tympanic membrane

Ossicles _____ sound and ___ fluid within inner ear

amplify; move

What are the 4 steps in hearing?

1. sound waves vibrate the tympanic membrane

2. Auditory ossicles vibrate, pressure is amplified

3. Pressure waves created by stapes pushing on the oval window move through fluid in the scala vestibuli

4a. Sound with frequencies below hearing level go through the helicotrema and do not excite hair cells

4b. Sound in the hearing range go through the cochlear duct, vibrating the basilar membrane and deflecting hairs on inner hair cells.

vestibules or maculae maintain a _____ and can sense ______.

static equilibrium; linear acceleration

Semicircular canals maintain _____ planes, and can sense _______.

X, Y, and Z planes; rotational acceleration.

Hair cells in the ear ____ with the fluid movement in inner ear, speed and direction of it is interpreted by the _____

bend; brain

Motion sickness is caused by _______ confusing integrative centers. Ears say the body is moving, Eyes say the body isn’t, etc.

conflicting sesnory input

Benign positional vertigo (“Otoconia“) is caused by the detatchment of the ____.

otolith