UNIT A: SENSES

Question 1

1. Chemoreceptors:

Answer 1

receive chemical information from dissolved substances. (ex. taste, smell, pH sensors, CO2 receptors)

Question 2

2. Baroreceptors –

Answer 2

receive information from manual stimulation
->Touch, Pressure, Proprioceptors (position and movement), Pain, Heat

Question 3

3. Osmoreceptors –

Answer 3

sensitive to fluid levels in the body.
(ex. the hypothalamus is the thirst center of the body)

Question 4

4. Mechanoreceptors –

Answer 4

receive mechanical, vibrational stimulation. (ex. the ear)

Question 5

5. Photoreceptors –

Answer 5

receive electromagnetic (light) stimulation.
(ex. the eye)

Question 6

EXTERNAL EYE

eyelid:

Answer 6

protects eye

Question 7

EXTERNAL EYE

eyelash:

Answer 7

prevents small particles from entering

Question 8

EXTERNAL EYE

lacrimal glands:

Answer 8

produce a salty germicidal fluid that washes particles out and keeps eye lubricated. Fluid evaporates or drains into nasal cavity

Question 9

EXTERNAL EYE

conjunctiva:

Answer 9

a thin protective layer on the cornea

Question 10

EXTERNAL EYE

nasal cavity:

Answer 10

drains fluid from the lacrimal glands into the nose

Question 11

INTERNAL EYE

sclera:

Answer 11

connective tissue encases and protects the eyeball (white)

Question 12

INTERNAL EYE

cornea:

Answer 12

transparent portion of the sclera

Question 13

INTERNAL EYE

choroid:

Answer 13

pigmented tissue contains blood vessels to nourish the back of the eye. Absorbs light and prevents reflections

Question 14

INTERNAL EYE

ciliary body:

Answer 14

smooth muscle contracts / relaxes to change the shape of the lens

Question 15

INTERNAL EYE

suspensory ligaments:

Answer 15

cause the lens to flatten if the muscles are relaxed, for far vision

Question 16

INTERNAL EYE

iris:

Answer 16

Pigmented, composed of muscles that control the amount of light that enters

Question 17

INTERNAL EYE

lens:

Answer 17

focuses light onto the retina

Question 18

INTERNAL EYE

pupil:

Answer 18

the opening of the iris, allows light into the eye

Question 19

INTERNAL EYE

aqueous humour:

Answer 19

fluid between cornea and the lens

Question 20

INTERNAL EYE

vitreous humour:

Answer 20

jelly-like fluid, gives structure to the eye and prevents retina from caving in

Question 21

INTERNAL EYE

retina:

Answer 21

consists of two types of photoreceptor cells, rods and cones. Organize visual information before impulses are sent to the brain

Question 22

INTERNAL EYE

rods:

Answer 22

night vision, abundant in the eye, mainly in the peripheral portion of the retina, sensitive to slight movements in dim light

Question 23

INTERNAL EYE

cones:

Answer 23

color vision, located at the fovea centralis, sensitive to color and bright light

Question 24

INTERNAL EYE

optic nerve:

Answer 24

carries visual information to the occipital lobe of the brain

Question 25

INTERNAL EYE

fovea centrails:

Answer 25

area of highly concentrated cones, where light is focused for clear, precise color vision

Question 26

INTERNAL EYE

optic disc (blind spot):

Answer 26

where the optic nerve leaves the retina, a spot where photoreceptors are absent

Question 27

FOCUSING & ACCOMMODATION

extrinsic eye muscles:

Answer 27

control movements of the eyeball within the socket (side to side or up and down). There are three pairs of muscles

Question 28

FOCUSING & ACCOMMODATION

ciliary muscles:

Answer 28

control the shape of the lens (contracted muscles make the lens round, relaxed muscles flatten the lens)

Question 29

FOCUSING & ACCOMMODATION

accommodation:

Answer 29

is the flattening or rounding of the lens in order to focus objects on the retina

Question 30

DISORDERS

myopia:

Answer 30

(nearsightedness)
light focuses in front of the retina, can see near objects clearly
*Concave lenses help

Question 31

DISORDERS

hyperopia:

Answer 31

(farsightedness)
light focuses behind the retina, can see distant objects clearly *Convex lenses help

Question 32

DISORDERS

astigmatism:

Answer 32

irregular shape to the eyeball or lens causing distortions, light rays scatter

Question 33

THE OUTER EAR

pinna:

Answer 33

folds of the visible ear. Helps to funnel sound waves into the ear

Question 34

THE OUTER EAR

auditory canal:

Answer 34

carries sound waves to the middle ear (eardrum). The canal is lined with hairs, sweat and glands that produce earwax. These structures help prevent foreign bodies from getting into the ear

Question 35

THE MIDDLE EAR

tympanic membrane:

Answer 35

eardrum, a flexible membrane that vibrates when hit with sound waves

Question 36

THE MIDDLE EAR

ossicles:

Answer 36

the three bones in the ear, amplify sound vibrations using leverage

-Malleus (hammer)

-Incus (anvil)

-Stapes (stirrup)

Question 37

THE MIDDLE EAR

Eustachian tube:

Answer 37

extends from the middle ear to the nasopharynx, allows for the equalization of pressure in the ear when you swallow

Question 38

THE INNER EAR

oval window:

Answer 38

attached to the stirrup, as the stirrup moves the oval window moves creating vibrations in the fluid of the cochlea

Question 39

THE INNER EAR

round window:

Answer 39

at the far end of the cochlea, puffs outwards to relieve pressure from the oval window creating waves in the cochlear fluid

Question 40

THE INNER EAR

cochlea:

Answer 40

coiled, fluid filled tube that converts mechanical vibrations into nerve impulses