CONCEPT REVIEW ( Special Senses)

Question 1

The special senses include smell, taste, ………., hearing, and equilibrium. …………… for these senses are located in complex sensory organs of the head.

Answer 1

VISION , RECEPTORS

The special senses include smell, taste, vision, hearing, and equilibrium. Receptors for these senses are located in complex sensory organs of the head.

Question 2

The receptors for olfaction, olfactory receptor cells, are in the …………………………………. in the superior area of the …………… cavity.

Answer 2

olfactory epithelium, nasal

The receptors for olfaction, olfactory receptor cells, are in the olfactory epithelium in the superior area of the nasal cavity.

Question 3

Olfactory hairs respond to ?

Answer 3

inhaled chemicals, or odorants

Question 4

What do supporting cells do?

Answer 4

detoxify chemicals, electrically insulate receptors, and provide support and nourishment

Question 5

What do Basal cells do?

Answer 5

continually divide to produce new olfactory receptor cells

Question 6

What do Olfactory glands do?

Answer 6

Olfactory glands produce mucus to dissolve odorants.

Question 7

What’s the role of Olfactory receptors?

Answer 7

Olfactory receptor cells are excited by odorant molecules binding to odorant binding proteins. This results in production of a generator potential, which may lead to an action potential.

Question 8

Does Olfaction have a low or high threshold?

Answer 8

Olfaction has a low threshold; only a few molecules are needed to be perceived as an odor. Adaptation to odors occurs rapidly.

Question 9

Explain the last process of Olfaction

Answer 9

Bundles of axons of olfactory receptor cells pass through foramina in the cribriform plate of the ethmoid bone and form the left and right olfactory nerves, which convey impulses of smells to the olfactory bulbs, olfactory tracts, limbic system, and cerebral cortex (temporal and frontal lobes).

Question 10

How do Impulses for Gustation travel?

Answer 10

Impulses for taste propagate along the facial, glossopharyngeal, and vagus nerves to the brain.

Question 11

Gustation involves distinguishing five tastes:

Answer 11

bitter, sour, salty, sweet, and umami.

Question 12

MISSING WORDS

Receptors for taste are located in……………….. Taste buds are found on the tongue in …………………,
fungiform, ……………, and filiform papillae. …………….. increase friction with food to help manipulate it. Each taste bud consists of supporting cells, ………………, and gustatory receptor cells that have a gustatory hair projecting from the cell through a taste pore to the surface.

Answer 12

Taste buds, vallate, foliate, Papillae, basal cells

Question 13

What do Tastants do? How does the Gustation system react to them?

Answer 13

Tastants dissolve in saliva and bind to gustatory hairs, stimulating the receptor cells to have a receptor potential that stimulates the release of neurotransmitter, which can generate action potentials in first­order neurons.

Question 14

Explain how taste varies

Answer 14

The threshold for each of the primary tastes varies, and adaptation to taste occurs quickly.

Question 15

Three cranial nerves propagate gustation impulses to the medulla oblongata; some then project to
the : 4 other areas…

Answer 15

limbic system, hypothalamus, thalamus, and cerebral cortex (parietal lobe).

Question 16

MISSING WORD

The eye is protected by eyelids, eyelashes, eyebrows, and a ………………………….?

Answer 16

lacrimal apparatus.

Question 17

The accessory structures of the eye include ?

Answer 17

eyelids, eyelashes, eyebrows, lacrimal apparatus, and extrinsic eye muscles.

Question 18

The eyelids shade and protect the eyes, and spread lubricants over the eyeballs. Each eyelid contains ?

Answer 18

the orbicularis oculi, meibomian glands, and conjunctiva.

Question 19

The lacrimal apparatus includes ?

Answer 19

the lacrimal glands, lacrimal ducts, lacrimal puncta,

lacrimal canals, lacrimal sac, and nasolacrimal duct.

Question 20

How many extrinsic muscles move each eyeball? What are the names?

Answer 20

6, the superior rectus, inferior rectus, lateral rectus,

medial rectus, superior oblique, and inferior oblique.

Question 21

MISSING WORD

The eye is constructed of………………. layers.

Answer 21

three

Question 22

The wall of the eyeball has three layers: name them

Answer 22

the fibrous tunic, vascular tunic, and retina.

Question 23

The superficial fibrous tunic consists of the

Answer 23

posterior, tough, protective, white sclera

Question 24

MISSING WORDS

the anterior, curved, transparent ________. The scleral venous___________is at the junction of the sclera
and cornea, and functions to drain aqueous _______.

Answer 24

cornea, sinus, humor

Question 25

The vascular tunic is between the fibrous tunic and retina. How are nutrients delivered?

Answer 25

The vascular choroid supplies

nutrients to the retina and absorbs scattered light rays

Question 26

MISSING WORDS

The ciliary body consisting of the _____________ and ciliary muscle that secretes ___________ and controls the shape of the lens, and the ______, which regulates the diameter of its central opening, the _______.

Answer 26

cilliary processes, aqueous humor, iris, pupil

Question 27

What is the innermost tunic of the eye?

Answer 27

The retina

Question 28

MISSING WORDS

The outer pigmented layer prevents scattering of ___________. The neural layer contains photoreceptors, bipolar cells, and ____________. The _________ are photoreceptors that are stimulated by even low light and allow night or dim vision. ________ are photoreceptors that are stimulated by bright light and produce color vision.

Answer 28

light rays, ganglion cells, rods , cones

Question 29

Visual information passes from photoreceptors to

Answer 29

bipolar cells to ganglion cells

Question 30

Axons of ganglion cells extend to the

Answer 30

optic disc

Question 31

What is the blind spot of the eye & why?

Answer 31

Optice disc, no rods and cones

Question 32

Where in the eye are only cones situated?

Answer 32

The central, posterior portion of the retina contains only cones. This area, the fovea centralis, is the area of highest visual acuity.

Question 33

What is posterior to the pupil and iris?

Answer 33

The lens is posterior to the pupil and iris,

Question 34

The LENS is transparent and contains proteins called ___________. The lens functions to focus images on the retina.

Answer 34

crystallins

Question 35

The lens divides the interior of the eyeball into the anterior cavity and the ____________. The anterior cavity, the space anterior to the lens, contains anterior and posterior chambers filled with _____________. The larger vitreous chamber, between the lens and the retina, contains the ________________.

Answer 35

vitreous chamber, aqueous humor, vitreous body

Question 36

Image formation involves refraction of light rays, accommodation, pupil constriction, and ________?

Answer 36

convergence.

Question 37

Light rays entering the eye undergo __________, the bending of light rays at each surface of the cornea and the lens, which focuses an inverted image on the fovea centralis of the retina.

Answer 37

refraction

Question 38

What is Accommodation?

Answer 38

an increase in the curvature of the lens for near vision.

Question 39

An ___________ eye is a normal eye that can refract light rays so that a clear image is focused
on the retina. _________ (nearsightedness) is the inability to focus properly on distant objects. __________ (farsightedness) results in the inability to focus on nearby objects

Answer 39

emmetropic, Myopia, Hyperopia

Question 40

When there is an irregular curvature to the cornea or lens that causes parts of an image to be out of focus or distorted?

Answer 40

Astigmatism

Question 41

Human eyes have __________ to allow depth perception. When objects move closer, the eyes must move medially and undergo _________, so that light rays from the object can strike the same points on both eyes.

Answer 41

binocular vision, convergence

Question 42

The neural pathway of light is photoreceptors →

Answer 42

bipolar cells → ganglion cells → optic nerve → primary visual cortex.

Question 43

Photoreceptors have photopigments that transduce light energy into a receptor potential. Rods have the photopigment ___________; cones have three different cone photopigments that absorb different colors of light.

Answer 43

rhodopsin

Question 44

Photopigments contain two parts: the glycoprotein _______, and retinal, the light­absorbing part of photopigments. When retinal absorbs light, it changes shape from cis to trans in a process called __________ . The trans­retinal separates from opsin during bleaching. The photopigment finally undergoes regeneration when cis­retinal binds to opsin.

Answer 44

opsin, isomerisation

Question 45

Light adaptation occurs when photoreceptors adjust to a brighter environment by decreasing their sensitivity as increasing amounts of ___________ are bleached.

Answer 45

photopigment

Question 46

____________ occurs when photoreceptors increase sensitivity by increasing photopigment regeneration. Only rods function at low light intensity.

Answer 46

Dark adaptation

Question 47

Light striking the retina activates enzymes that lead to a receptor potential in the photoreceptors, then receptor potentials in ____________ that synapse on photoreceptors.

Answer 47

bipolar cells

Question 48

Bipolar cells transmit receptor potentials to ganglion cells, which generate action potentials. Ganglion cell axons exit the eyeball as the optic nerve. When optic nerve axons pass through the _________, they either cross to the opposite side or continue straight ahead, forming the optic tract that enters the ___________. Optic radiations allow for projection to the primary visual areas of the cerebral cortex.

Answer 48

optic chiasm, thalamus

Question 49

The pathway of sound is tympanic membrane → ?

Answer 49

ossicles → oval window → cochlea → vestibulocochlear nerve → primary auditory cortex.

Question 50

Sound waves are alternating _________________regions traveling in a medium.

Answer 50

high­ and low­ pressure