Sensory Overview

Question 1

Sensory Pathway

Answer 1

stimulus (touch, heat, pain, etc), to receptor (acts as transducer), cell signal (usually change in potential-graded potential), (stimulus>threshold> action potential to CNS), CNS interprets “decides” what is noticed

Question 2

transducer

Answer 2

need to convert stimulus into something the body understands

Question 3

CNS interprets and decides what?

Answer 3

forget wearing clothes/ notice itchy clothes

Question 4

graded potential

Answer 4

change in potential due to stimulus binding and opening channels (Ca and K-doesn’t have to lead to action potential) up or down, not all or nothing

Question 5

special senses

Answer 5

(usually conscious) vision, hearing, taste, smell, equilibrium

Question 6

somatic senses

Answer 6

(usually conscious) touch, temperature, nociception (pain, itch), proprioception

Question 7

somatic stimuli

Answer 7

(usually subconscious) muscle length and tension, proprioception

Question 8

visceral stimuli

Answer 8

(usually subconscious) blood pressure, distension of gastrointestinal tract, blood glucose concentration, internal body temperature, osmolarity of body fluids, lung inflation, pH of cerebrospinal fluid, pH and oxygen content of blood

Question 9

proprioception

Answer 9

brain knowing where body is in space

Question 10

inhibition/excitation

Answer 10

inhibition (left and negative), excitation (right and positive)

Question 11

low pitch sounds

Answer 11

travel further

Question 12

high pitch sounds

Answer 12

at beginning

Question 13

loud sounds

Answer 13

wear down first part of hair

Question 14

strong effect of hearing

Answer 14

knowing where body is in space

Question 15

regular threshold

Answer 15

depolarization

Question 16

perception threshold

Answer 16

teaches brain to ignore wearing clothing

Question 17

habituation

Answer 17

a person responds less and less to a repeated stimulus

Question 18

olfactory pathways from the nose

Answer 18

project through the olfactory bulb to the olfactory cortex

Question 19

most sensory pathways project to the…

Answer 19

THALAMUS- the thalamus modifies and relays information to cortical centers

Question 20

equilibrium pathways project primarily to…

Answer 20

the cerebellum

Question 21

receptors to particular forms of energy

Answer 21

naked (“free”) nerves, complex neural receptors encased in protective tissue capsules, smell receptors are neurons, nonnueral receptors for 4 special senses

Question 22

smell receptors are..

Answer 22

neurons! constantly remaking neurons in nose

Question 23

simple receptors

Answer 23

neurons with free nerve endings, may have myelinated or unmyelinated axons

Question 24

complex neural receptors

Answer 24

nerve endings enclosed in connective tissue capsules

Question 25

special sense receptors

Answer 25

cells that release neurotransmitter onto sensory neurons, initiating an action potential

Question 26

types of sensory receptors

Answer 26

chemoreceptors, mechanoreceptors, thermoreceptors, photoreceptors, nocireceptors (pain receptors)

Question 27

chemoreceptors

Answer 27

respond to chemical ligand: taste, smell (oxygen, pH, various organic molecules such as glucose, carbon dioxide)-dissolved in saliva and mucous

Question 28

mechanoreceptors

Answer 28

respond to mechanical energy pressure and sound: touch and hearing, physically manipulated by a stimulus (pressure (baroreceotors), cell stretch (osmoreceptors), vibration, acceleration, sound)

Question 29

photoreceptor

Answer 29

for vision response to light; photons of light

Question 30

thermoreceptors

Answer 30

respond to temperature (each responds to a different range in temps and wave lengths); varying degrees of heat

Question 31

nociceptors

Answer 31

varying degrees of heat

Question 32

receptor characteristics

Answer 32

changes in membrane potential, threshold potential leading to ap, perceptual threshold potential, habituation, brain sensory modules

Question 33

changes in membrane potential

Answer 33

ion channels and 2 degree messengers (receptor characteristics)

Question 34

threshold potential leading to action potential

Answer 34

doesn’t reach threshold, doesn’t react (receptor characteristics)

Question 35

perceptual threshold potential

Answer 35

reaches threshold, CNS notices (receptor characteristics)

Question 36

brain sensory modules

Answer 36

not sent to right place, recognized wrong; can’t tell if being touched in one spot or 2

Question 37

every sense goes through thalamus except for...

Answer 37

SMELL

Question 38

stimulus properties

Answer 38

MILD; modality (stimulus sensitivity and termination of neuron), location (receptor field, neighbor sensory cells-lat inhib- coding or cell label (cold receptors); intensity (strength of stimulus/freq ap); duration

Question 39

localization of sound

Answer 39

signals from right side read the brain first

Question 40

lateral inhibition

Answer 40

capacity of an excited neuron to reduce the activity of its neighbors- disabled the spreading of action potentials from excited neurons to neighboring neurons in the lateral direction (edged bounded by 8’s)

Question 41

coding for stimulus intensity and duration

Answer 41

integrated in trigger zone, frequency, strength and duration of ap is proportional to stimulus intensity, neurotransmitter release varies w pattern of ap arriving at the axon terminal

Question 42

phasic receptors

Answer 42

rapidly adapt to a constant stimulus and turn off

Question 43

tonic receptors

Answer 43

slowly adapting receptors that respond for the duration of a stimulus