Chapter 10—Special Senses

Question 0

Humans have binocular vision. What does this mean?

Answer 0

We see because of the overlapping of 2 visual fields—left and right

Question 1

Describe the lens.

Answer 1

The lens is biconvex and flips images on retina when viewed.

We must “learn” to flip them right-side up again in brain

Question 2

List tunics in order from outer to inner.

Answer 2

Sclera
Choroid
Retina

Question 3

Describe the sclera.

Answer 3

It is the white, fibrous part of eye.

It includes the cornea.

Question 4

What is the cornea? How does it receive nutrients?

Answer 4

Clear, anterior portion of eye that contains lots of nerve endings.
Nutrients through diffusion.

Question 5

Describe the choroid.

Answer 5

Darkly pigmented part that prevents light from scattering in the eye.
*blood-rich

Question 6

What does the middle tunic include?

Answer 6

Choroid=ciliary body and iris

Question 7

What is the ciliary body?

Answer 7

Smooth muscle structure to which the lens is attached. Controls the movement of the lens.

Question 8

What is the iris?

Answer 8

Colored muscle that contains the pupil.

The circulatory and radially arranged smooth muscles act like the diaphragm of a camera.

Question 9

What is the pupil?

Answer 9

Rounded opening through which light passes. Regulates amount entering

Question 10

What is the retina?

Answer 10

Innermost layer with photoreceptors.
(Rods & Cones)
Extends anteriorly onto ciliary body

Question 11

What are gross eye movements controlled by?

Answer 11

Extrinsic eye muscles

Question 12

What kind of vision do rods help with? Cones?

Answer 12

Rods-Black and white

Cones-Color

Question 13

Why can’t you look directly at a dim star and see it?

How could you see it?

Answer 13

Rods, which would be responsible for seeing it, are in the periphery. Cones are the ones in direct vision.

Look at it with peripheral vision.

Question 14

What is the optic disk?

Answer 14

Where the optic nerve leaves the eyeball (blind spot) *no photoreceptors here.

Question 15

What wavelengths to human cones detect?

Answer 15

Red, blue, and green

Question 16

What color is the iris in an albino?

Answer 16

Red…no color so choroid is seen

Question 17

What are cataracts?

Answer 17

Result from hardening of the lens. Causes vision to become hazy and blindness can result

Question 18

What is colorblindness?

Answer 18

Lack of three cones.

Question 19

Glaucoma?

Answer 19

Is the result of Aqueous humor not being reabsorbed into venous blood through canal of Sclemm. Drainage is blocked and pressure builds up.

Question 20

Fovea centralis?

Answer 20

Area of sharpest vision

Question 21

Aqueous humor? Where found and what it does?

Answer 21

Behind cornea

Helps maintain appropriate pressure in eye

Question 22

Vitreous humor?

Answer 22

Posterior to lens

Gel like substance; round shape of eye

Question 23

What is the job of the meibomian glands?

Answer 23

Secretes oily substances to lubricate eye(modified sebaceous glands)

Question 24

What is pinkeye? What is it caused by?

Answer 24

Conjunctivitis | Caused by bacteria getting in and causing inflammation

Question 25

What is accommodation?

Answer 25

Adjustment of lens to let us see close objects

Question 26

Convergence?

Answer 26

The eyes move medically when we view close objects.

Question 27

External ear?

Answer 27

Pinna(auricle) External auditory canal Tympanic membrane(eardrum)

Question 28

Middle ear?

Answer 28

``` Ossicles Auditory tube (the Eustacian tube) ```

Question 29

Inner ear?

Answer 29

Cochlea Vestibule Semicircular canals

Question 30

What are mechanoreceptors?

Answer 30

Receptors stimulated by the move,end of fluids or vibration

Question 31

What do sound waves entering the external canal hit first?

Answer 31

The eardrum(tympanic membrane)

Question 32

Technical name for earwax? What produces it?

Answer 32

Cerumen | Ceremonious glands

Question 33

What are the ossicles? Names/nicknames? Location?

Answer 33

Malleus(hammer) Incus(anvil) Stapes(stirrup) Located in middle ear

Question 34

What are otoliths? What do they detect? What are they made of?

Answer 34

Tiny stones made of calcium As the head moves, they roll in response to changes in pull of gravity; this movement created pull on gel(macula), which in turn slides over hair cells, bending them *movement and position of head

Question 35

Static equilibrium vs dynamic

Answer 35

Static: macula/otoliths...report on position of head with respect to gravity when body is still Dynamic: lag of cupula...body moving

Question 36

Organ of Corti?

Answer 36

Contained by cochlea It has hair cells embedded on the basilar membrane and a tectorial membrane on top that cause hair cells to move when stimulated.

Question 37

What are the vestibule and semicircular canals responsible for?

Answer 37

Equilibrium and balance | ...sends signals to cerebellum

Question 38

Where does the cochlea send signals? Responsibility?

Answer 38

To temporal bone(auditory cortex) | Hearing

Question 39

How does sound move through ear?

Answer 39

From external auditory canal and pinna to tympanic membrane...then to malleus(hammer)...to incus(anvil)...to the stapes(stirrup)...to oval window where fluid is set in motion exciting hearing receptors

Question 40

Definition of deafness?

Answer 40

Hearing loss of any degree

Question 41

Conduction vs Sensorineural deafness

Answer 41

Conduction: interference with conduction of sound vibration to fluid of inner ear(hearing aids help) Sensorineural: degeneration or damage to receptor cells in organ of Corti, cochlear nerve, or neurons in auditory cortex Hearing aids won't help

Question 42

What are Olfactory and Gustatory receptors collectively called?

Answer 42

Chemoreceptors

Question 43

What must happen to the chemicals associate with taste and smell?

Answer 43

Dissolved in mucous or saliva

Question 44

4 basic tastes? Their location on tongue? What taste receptors respond to?

Answer 44

Sour: sides of tongue (H+ ions; acidity) Salty: middle of tongue (metal ions) Bitter: back of tongue (alkaloids) Sweet: tip of tongue (sugar, saccharine, amino acids)

Question 45

Where do taste buds send signals to?

Answer 45

Gustatory cortex

Question 46

What cranial nerve serves anterior tongue?

Answer 46

Facial nerves

Question 47

Cranial nerves associated with taste?

Answer 47

Facial Glossopharyngeal Vagus