Chapter 16 - Senses

Question 1

– in neuroscience, this term can refer either to a protein that binds and responds to
chemical messenger or it can refer to a cell or structure that converts one kind of energy into
an electrical signal within a cell

Answer 1

Receptors

Question 2

used for vision

Answer 2

Photoreceptors

Question 3

used for hearing; touch; proprioception; respond to

stretch or bending of part of a cell

Answer 3

Mechanoreceptors

Question 4

used for sensing taste (tongue), smell (olfactory), osmolarity
(hypothalamus), O2, CO2 (in hypothalamus and near heart) & H+ (in brainstem)

Answer 4

Chemoreceptors

Question 5

create a sensation of pain; work by binding chemicals released
during inflammation and tissue injury; technically, they are chemoreceptors

Answer 5

Nociceptors

Question 6

– pressure (actually a type of mechanoreceptor); found in walls
of major blood vessels and in the lungs to monitor lung expansion and stretch

Answer 6

Baroreceptors

Question 7

provide information about position, stretch or force of
contraction of muscles, tendons & ligaments in the body. These allow you to
know the position of body parts relative to each other.

Answer 7

Proprioceptors

Question 8

– the energy that activates the receptor

Answer 8

Stimulus

Question 9

– process of changing stimulus into a change in membrane potential

Answer 9

Transduction

Question 10

graded potential generated by sensory receptor; due to

opening/closing of gated channel

Answer 10

Receptor potential

Question 11

– the type of energy sensed (e.g. light or sound)

Answer 11

Modality

Question 12

strength of stimulation (e.g. how bright or how loud)

Answer 12

Intensity

Question 13

– one afferent neuron and all the receptors that send it signals

Answer 13

Sensory unit –

Question 14

the sensory area covered by one afferent neuron; one sensory unit
defines a receptive field

Answer 14

Receptive field

Question 15

– precision of the sensation; often related to ability to localize stimulus
(generated by size of receptive fields

Answer 15

Acuity

Question 16

decreased receptor response with continued stimulation; enhances
ability to detect change & ignore background

Answer 16

Adaptation

Question 17

something that happens both at the level of the individual receptor and in the CNS.

Answer 17

Adaptation

Question 18

are receptors that adapt very slowly and generate steady nerve
impulses.

Answer 18

Tonic receptors

Question 19

c receptors generate a burst of action potentials when first stimulated
(on/off type response); they adapt quickly

Answer 19

Phasic receptors

Question 20

– respond to chemicals produced by damage to tissues

Answer 20

Nociceptors

Question 21

Bradykinin (most potent)
 Prostaglandins
 Serotonin
 Histamine

Answer 21

most important and common stimulators of somatic pain.

Question 22

• Pain can be a sharp, stabbing sensation that occurs very rapidly.
  pain conducted via myelinated fibers

Answer 22

Fast

Question 23

pain can be a longer-lasting, dull, diffuse

sensation. pain conducted unmyelinated fibers

Answer 23

slow

Question 24

pain comes from

stimulation of skin or proprioceptors

Answer 24

Somatic

Question 25

pain due to injury to internal organs

Answer 25

visceral

Question 26

The location that feels pain has somatosensory fibers coming in along the same dorsal root as visceral sensory fibers from the affected organ.

Answer 26

Referred Pain

Question 27

``` mechanisms for inhibiting nerve signals along pain pathways using enkephalin neurotransmitters (endogenous opiates) as well as pre-synaptic inhibition. ```

Answer 27

, spinal gating

Question 28

chemoreceptors for external sensing

Answer 28

Olfaction (smell) & Gustation (taste)

Question 29

Much of sense of taste

Answer 29

olfaction.

Question 30

smell

Answer 30

oflaction

Question 31

taste

Answer 31

Gustation

Question 32

taste that detects compounds like quinine; GPCR

Answer 32

Bitter –

Question 33

taste that detects H+ ions; open channels in membrane for H+

Answer 33

Sour/acid

Question 34

n distinguish between something like 2000-4000 different chemicals; it does this using about 400 different odorant receptors.

Answer 34

The olfactory system

Question 35

Structures used for detecting orientation to gravity, as well as movement and acceleration, key to balance, are

Answer 35

the vestibule & semicircular canals.

Question 36

detects compression waves of molecules in air

Answer 36

hearing

Question 37

(X axis =

Answer 37

time

Question 38

y axis =

Answer 38

pressure

Question 39

The height of a peak (trough to peak measure) is its

Answer 39

amplitude

Question 40

The number of waves that pass the measuring point in a second is the

Answer 40

frequency

Question 41

measured in decibels (dB), the wave generates the volume of the sound.

Answer 41

amplitude

Question 42

, a logarithmic scale of the energy in the sound.

Answer 42

decibels (dB)

Question 43

of the compression waves generates the pitch of the sound. is measured in cycles per second passing a point in space. This is called Hertz (Hz).

Answer 43

frequency

Question 44

Humans hear from

Answer 44

200-10,000 Hz

Question 45

Sound over ___can cause permanent hearing loss if exposed to it for very long

Answer 45

90db

Question 46

Sound causes pain around

Answer 46

120db

Question 47

sound waves are collected and directed by the outer structures towards the eardrum or ___

Answer 47

Tympanic membrane

Question 48

vibration of the eardrum is translated into movement of the ____

Answer 48

occicles

Question 49

a membrane covering an opening into the vestibule

Answer 49

oval window

Question 50

can tighten the eardrum to reduce the force of | pressure waves in the scala in the cochlea

Answer 50

Tensor tympani

Question 51

can reduce stapes movement, also reducing the pressure (volume) of a wave in the scala of the cochlea.

Answer 51

Stapedius

Question 52

protect the ear from loud noises.

Answer 52

tympanic reflex

Question 53

used for balance , filled with endolymph

Answer 53

semicircular canals

Question 54

full of fluid, perilymph, which flows through the scala vestibuli to the helicotrema

Answer 54

the Vestibule

Question 55

are part of the coiled cochlea, which detects sound

Answer 55

scala | vestibuli & scala tympani

Question 56

used for balance, are also connected to the vestibule

Answer 56

semicircular canals (ducts),

Question 57

In both the cochlea and semicircular canals, there is an additional inner membranous tunnel or canal filled with

Answer 57

endolymph.

Question 58

The movement of the stapes on the oval window sets up a | pressure/compression wave in the perilymph in the

Answer 58

Cochlea

Question 59

The vibration of the | basilar membrane will lead to the bending of

Answer 59

stereocilia on the surface of the hair | cells in the organ of Corti.

Question 60

The basilar | membrane is stiffer near the

Answer 60

round window

Question 61

The basilar | membrane is less stiff near the

Answer 61

helicotrema.

Question 62

Light will travel through the

Answer 62

``` cornea, aqueous humor (anterior chamber), lens, vitreous body (posterior chamber) and the first 4 layers of the retina ```

Question 63

the fluid in the anterior chamber of the eye. produced by | the ciliary body and reabsorbed into the blood by the scleral venous sinus.

Answer 63

Aqueous humor

Question 64

It is a common cause of blindness in the elderly.

Answer 64

glaucoma.

Question 65

Light is photons traveling in waves and is part of the | electromagnetic spectrum

Answer 65

Light & Vision:

Question 66

Different wavelengths of light are perceived as different colors when they excite the color photoreceptors called

Answer 66

cones

Question 67

For ___, light is reflected by the colors (pigments) of the objects you look at.

Answer 67

vision

Question 68

The excited photopigments activate, ____ protein

Answer 68

G

Question 69

the world has to shrink to the size of the fovea or macula for phototopic (daytime) vision. Light rays are bent to make this happen; it’s called

Answer 69

refraction

Question 70

occurs when light rays hit something with a | different density

Answer 70

refraction

Question 71

- where optic nerve leaves eyeball; medial to macula; its | presence creates the “blind spot” in the visual field

Answer 71

retina

Question 72

center of focus for retina when you look directly | at something;

Answer 72

Macula lutea or macula

Question 73

– center of macula; all cones; highest density

Answer 73

fovea

Question 74

create black & white vision in dim light creating scotopic (nighttime) vision; only create a perception of light or no light; they do not help in perception of color

Answer 74

rods

Question 75

– create color vision in bright light creating phototopic (daytime) vision

Answer 75

cones

Question 76

– Refraction at the cornea and the filtering of the pupil combine with the lens to form a small, focused image on the retina, usually on the fovea when looking at something. upside down and backwards

Answer 76

Image Formation

Question 77

normal, relaxed vision, focused about 20 ft away.

Answer 77

Emmetropia

Question 78

– vision focused on a near object. This requires contraction of muscles attached to the eyeball to rotate both eyes medially so that reflected light from the near object can strike the fovea of both eyes at the same time

Answer 78

Convergence

Question 79

adjusting for near or far vision;includes | convergence, pupil constriction and rounding/thickening the lens for near vision

Answer 79

Accommodation

Question 80

hold the lens in place in the eyeball.

Answer 80

Suspensory ligaments

Question 81

is a circular muscle within the suspensory ligaments that hold the lens

Answer 81

ciliary | muscle

Question 82

when tthe suspensory ligaments stretch out the lens | making it thinner.

Answer 82

ciliary muscle relaxes

Question 83

it stretches the suspensory ligaments taking tension off the lens. This lets the lens get rounder and thicker for near vision

Answer 83

When the ciliary muscle contracts

Question 84

is regulated by reflex arcs that can be | stimulated by the amount of light.

Answer 84

Pupil size

Question 85

is the overriding | signal except in stress.

Answer 85

Light stimulation

Question 86

fibers stimulate pupil constriction, which aids | near vision

Answer 86

Parasympathetic fibers

Question 87

fibers stimulate pupil dilation, which can aid | distance vision.

Answer 87

Sympathetic fibers

Question 88

; requires bright light to stimulate cones

Answer 88

cones

Question 89

exciting red and green cones at the same time can create a | sensation of

Answer 89

yellow

Question 90

most of cones are in or near the

Answer 90

macula of the retina

Question 91

scotopic vision in dim light.are more densely packed at | the edges of retina, and fewer of them are found near the macula.

Answer 91

Rods

Question 92

fuzzy without color, but it does cover a wider field of vision than phototopic vision.

Answer 92

Scotopic vision

Question 93

When the 2 differing images from each retina are brought together in the cortex, your brain perceives those subtle differences in image positioning on the retinas as distance or depth.

Answer 93

Stereoscopic vision