Chapter 46: Sensory Systems

Question 1

first step of sensory transduction

Answer 1

change in the membrane potential of the receptor cell in response to specific type of stimulus

Question 2

receptor potential

Answer 2

change in the membrane potential of a receptor cell

Question 3

ionotropic sensory receptors

Answer 3

mechanoreceptors, thermoreceptor, electroreceptors

Question 4

metabotropic sensory receptors

Answer 4

chemoreceptor, photoreceptor

Question 5

adaptation

Answer 5

enables an animal to ignore background or unchanging conditions while remaining sensitive to changes and new information

Question 6

chemoreceptors

Answer 6

receptor proteins that bind to specific molecules and are responsible of smell and taste

Question 7

olfaction

Answer 7

the sense of smell, dependent on chemoreceptors

Question 8

olfactory bulb

Answer 8

olfactory integration area of the brain

Question 9

odorant

Answer 9

molecule in the environment that binds to and activates an olfactory receptor protein on the cilia of olfactory receptor neurons

Question 10

pheromone

Answer 10

specialized chemical signal used for communication among individuals of the same species

Question 11

gustation

Answer 11

sense of taste, dependent on taste buds (chemoreceptors)

Question 12

mechanoreceptors

Answer 12

respond to mechanical forces

Question 13

merkel’s discs

Answer 13

adapt rather slowly and provide continuous information about anything touching the skin. most important tactile receptors

Question 14

meissner’s corpuscles

Answer 14

very sensitive, adapt rapidly, provide information about changes in things touching the skin

Question 15

ruffini endings

Answer 15

deeper in the skin, adapt slowly and are good at providing information about vibrating stimuli of low frequency

Question 16

pacinian corpuscles

Answer 16

adapt rapidly, provide information about vibrating stimuli of higher frequencies

Question 17

muscle spindles

Answer 17

stretch receptors. modified muscle cells embedded in connective tissue inside muscles and innervated by sensory neurons

Question 18

golgi tendon organ

Answer 18

type of mechanoreceptor.
found in tendons and ligaments
provides information about the force generated by a contracting muscle

Question 19

hair cells

Answer 19

mechanoreceptor for the vertebrate auditory system and vestibular system. ( Sound perceiving and equilibrium-maintaining systems)

Question 20

stereocilia

Answer 20

fingerlike projections of the cell membrane stiffened by cross-linked actin filaments

Question 21

tympanic membrane

Answer 21

covering the end of the auditory canal
vibrates in response to pressure waves traveling down the canal, converting the pressure waves to physical forces in the middle ear

Question 22

eustachian tube

Answer 22

filled with air, pressure equilibrates between the middle ear and the enviornment

Question 23

ossicles

Answer 23

composed of the malleus, incus, and stapes

transmits the vibrations of the tympanic membrane to oval window

Question 24

oval window

Answer 24

receives vibrations from stapes. pressure is now 20x greater than at tympanic membrane

Question 25

vestibular canal

Answer 25

part of the inner ear. organ of balance

Question 26

cochlea

Answer 26

part of the inner ear, organ hearing. long tapered coil structure. composed of vestibular membrane and the basilar membrane

Question 27

organ of corti

Answer 27

sits on the basilar membrane

traduces pressure waves into action potentials

Question 28

round window

Answer 28

flexible membrane at the end of the tympanic canal

Question 29

flexions

Answer 29

traveling waves

Question 30

cupula

Answer 30

gelatinous swelling enclosing a cluster of hair cell stereocilia

Question 31

rhodospin

Answer 31

vertebrate visual pigment

consists of opsin(protein) and 11-cis-retinal (light absorbing functional group)

Question 32

eye cups

Answer 32

organized photoreceptor cells

Question 33

ommatidia

Answer 33

optical unit, with its own narrow-angle lens

Question 34

sclera

Answer 34

spherical, fluid filled structure bounded by a tough connective tissue layer

Question 35

cornea

Answer 35

at the front of the eye
formed by sclera
transparent to allow light in

Question 36

iris

Answer 36

just inside the cornea
gives the eye its color
controls the amount of light that reaches the photoreceptor cells at the back of the eye

Question 37

pupil

Answer 37

central opening of the iris

Question 38

lens

Answer 38

crystalline protein

makes fine adjustments in the focus of images

Question 39

retina

Answer 39

photosensitive layer

Question 40

the two photoreceptors of the vertebrate retina

Answer 40

rod and cone cells (both modified neurons)

Question 41

rod cells

Answer 41

highly light-sensitiveand perceive shades of gray in dim light
3 segments: outer, inner, and synaptic terminal

Question 42

cone cells

Answer 42

function at high levels
responsible for high-acuity color vision

Question 43

fovea

Answer 43

area of the retina that receives light from the center of the visual field

Question 44

optic nerve

Answer 44

formed by the axons of ganglion cells

Question 45

ganglion cells

Answer 45

closest to the lens

fire action potentials

Question 46

bipolar cells

Answer 46

connect ganglion cells to photoreceptors

rate of neurotransmitters released from the bipolar cells determines the rate that ganglion cells fire action potentials

Question 47

horizontal cells

Answer 47

form synapses with neighboring photoreceptors and bipolar cells

Question 48

amacrine cells

Answer 48

form local interconnections between bipolar cells and ganglion cells.
some highly sensitive to motion or to changing illumination