chapter 16 senses

Question 1

Transduction

Answer 1

-the conversion of one form of energy to another
-Converts stimulus energy (light, smell, heat, touch, sound, etc.) into nerve signals

Question 2

Sensation

Answer 2

-sensory receptor detects stimulus, creates small local electrical change (the receptor potential)

Question 3

Perception

Answer 3

-conscious experience and interpretation of a stimulus
(Not all sensations lead to perception—many signals are filtered out before reaching cortex)

Question 4

Modality

Answer 4

-type of stimulus or the perception it produces
-Examples: vision, hearing, taste

Question 5

Sensory adaptation

Answer 5

-if a stimulus is prolonged, firing of the neuron gets slower over time and we become less aware of it

Question 6

Phasic receptors

Answer 6

-adapt quickly; burst of signals when stimulus starts, then reduce/stop signaling even if stimulus continues
-Examples: smell, hair movement, cutaneous pressure

Question 7

Tonic receptors

Answer 7

-adapt slowly; action potentials continue more steadily while stimulus is present
-Examples: body position, muscle tension, joint motion

Question 8

Thermoreceptors

Answer 8

respond to heat and cold

Question 9

Photoreceptors

Answer 9

the eyes, respond to light

Question 10

Nociceptors

Answer 10

-respond to tissue injury, situations threatening damage
-Activation produces sensation of pain

Question 11

Chemoreceptors

Answer 11

-respond to chemicals
- examples: Odors, tastes, body fluid composition

Question 12

Mechanoreceptors

Answer 12

-respond to physical deformation
- example: Vibration, touch, pressure, stretch, tension, Includes organs of hearing and balance

Question 13

Exteroceptors

Answer 13

-sense stimuli external to body
- example: receptors for vision, hearing, taste, smell, and cutaneous sensations such as touch, heat, cold, and pain

Question 14

Interoceptors

Answer 14

-detect internal stimuli
- EX: Stomach, intestines, bladder
-Stretch, pressure, visceral pain (Internal organ pain), nausea

Question 15

Proprioceptors

Answer 15

-sense body position and movements
-location: In muscles, tendons, and joint capsules

Question 16

Unencapsulated nerve endings

Answer 16

dendrites with no connective tissue wrapping

Question 17

Merkel discs

Answer 17

-flattened nerve endings that terminate at tactile cells in basal layer of epidermis
-Detect light touch, texture, edges, shapes

Question 18

Meissner corpuscles

Answer 18

-2 or 3 nerve fibers within fluid-filled capsule of flattened Schwann cells
-Sense light touch and texture

Question 19

Krause end bulbs

Answer 19

sensory nerve fiber surrounded by connective tissue sheath

Question 20

Nociceptive pain

Answer 20

stems from tissue injury; occurs when nociceptors are activated

Question 21

Neuropathic pain

Answer 21

stems from injuries to nerves, spinal cord, meninges, brain

Question 21

Ruffini corpuscles

Answer 21

-Detect heavy touch, pressure, stretching of skin, deformation of fingertips, and joint movements

Question 22

Pacinian corpuscles

Answer 22

-Detect deep pressure and vibration
-Found in periosteum of bone, joint capsules, some viscera, and deep in the dermis (especially on hands, feet, breasts, and genitals)

Question 23

Visceral pain—

Answer 23

-arises from internal organs
-Diffuse, dull, and hard to locate
-nausea

Question 24

Deep somatic pain

Answer 24

-arises from bones, joints, muscles
-Examples: pain of arthritis, sprains, bone fractures

Question 25

Superficial somatic pain

Answer 25

-usually arises from the skin
Examples: pain of cuts, burns, insect stings

Question 26

Olfactory mucosa

Answer 26

patch of epithelium in roof of nasal cavity that houses receptor cells
-The fascicles are the olfactory nerve (CN I)

Question 27

Some odorants (ammonia, menthol, chlorine, capsaicin) act on…..

Answer 27

nociceptors of trigeminal nerve

Question 28

cerumen

Answer 28

traps microbes, waterproofs canal, and keeps eardrum pliable.

Question 29

Tympanic membrane

Answer 29

—the “eardrum,” a slightly conical membrane, vibrates in response to sound
-vagus and trigeminal nerves, so highly sensitive to pain
-

Question 30

Tympanic cavity

Answer 30

-air-filled, wide space between outer and inner ears

Question 31

Auditory ossicles

Answer 31

-three smallest bones of body; connect tympanic membrane to inner ear

Question 32

Tympanostomy

Answer 32

lancing tympanic membrane and draining fluid from tympanic cavity

Question 33

Otitis media (middle-ear infection)

Answer 33

-common in children
-Infections easily spread from throat to tympanic cavity and mastoid air cells
-symptoms: Fluid accumulates in tympanic cavity producing pressure, pain, and impaired hearing
Can spread, leading to meningitis
-hearing loss
- common bacteria rhinovirus, streptococcus, rsv

Question 34

Vestibule

Answer 34

Contains organs of equilibrium (balance)

Question 35

400 to 700 nm

Answer 35

Human vision limited to wavelengths of light from …

Question 36

superior oblique

Answer 36

CN IV innervates

Question 36

Tarsal glands

Answer 36

secrete oil that reduces tear evaporation

Question 37

lateral rectus

Answer 37

CN VI innervates

Question 38

other 4 extrinsic muscles

Answer 38

CN III innervates

Question 39

posterior chamber

Answer 39

between iris and lens

Question 40

suspensory ligament

Answer 40

focuses/unfocuses the lens

Question 40

anterior chamber

Answer 40

between iris and cornea

Question 41

Diabetic neuropathy

Answer 41

-retinal degeneration caused by effects of diabetes mellitus on retinal blood vessels
-Causes most adult blindness in U.S.
-Can often be prevented with early detection and control of diabetes

Question 42

night blindness

Answer 42

vitamin A deficiency can lead to….

Question 43

rods

Answer 43

-visual pigment rhodopsin (visual purple)
-(cause night blindness)

Question 44

Cones

Answer 44

-contain pigment called photopsin
- (cause color blindness)