receptor physiology

Question 1

ecteroreceptor

Answer 1

info from the external world

Question 2

proprioceptor

Answer 2

info from the musculoskeletal system (deep sensation from muscle and tendons and joints)

Question 3

interoreceptors

Answer 3

info from internal organs

Question 4

PNS is link bw what

Answer 4

periphery and CNS

Question 5

PNS consists of what and what are the divisions

Answer 5

nerve fibres that carry info bw CNS and other parts of body

afferent division: info from receptors about internal and ectermal enviroment to CNS- sensory- somatosensory, visceral sensory

efferent division- response that controls the effectors (skeletal muscles, tissues, organs- motor, somatic motor, visceral motor

Question 6

where does sensory info go

Answer 6

either to spinal chord or travel directly to higher levels in brainstem and thalamus to the primary sensory cortex

Question 7

first order sensory neuron

Answer 7

afferent neuron with its peripheral receptor that first detects stimulus

Question 8

second order sensory neuron

Answer 8

either spinal chord or medulla and synapsys with third order neuron

Question 9

third order sensory neuron

Answer 9

located in thalamus

Question 10

somatic sensory information

Answer 10

body sense- temp, pain, tactile, proprioceptive from skin, muscles, joints, and inner ear

Question 11

visceral sensory information

Answer 11

internal organs- pain temp, stretch, chemica, osmotic

Question 12

special sense sensory info

Answer 12

vision, hearing, balance, taste, smell

Question 13

where are sensory receptors located

Answer 13

at peripheral endings of afferent neurons

Question 14

what detects stimuli

Answer 14

sensory stimuli or receptor cells

Question 15

sensory transduction

Answer 15

conversion of different forms of energy into electrical signals- action potentials-

Question 16

modality

Answer 16

different types of sensation such as sound, light, taste, pain, touch

Question 17

photoreceptors

Answer 17

visible wavelengths of lighty

Question 18

photoreceptors

Answer 18

visible wavelengths of light

Question 19

mechanoreceptors

Answer 19

mechanical energy

Question 20

thermoreceptors

Answer 20

heat and cold

Question 21

nocioceptors

Answer 21

pain

Question 22

chemoreceptors

Answer 22

specific chemicals

receptors for smell, taste, o2 and co2 conc in blood and chemical content of digestive tract

Question 23

osmoreceptors

Answer 23

osmotic pressure

Question 24

adequate stimulus

Answer 24

least amount of energy to activate particular receptor. form of energy that receptor is most responsve

Question 25

law of specific nerve energies

Answer 25

sensation characteristic of each sensory neuron produced by its adequate stimulus

Question 26

categories of sensory receptors

Answer 26

free nerve endings- nociceptors

specialized endings of sensory neurons- encapsulated receptors- pacinian corpuscle, meissners corpuscles

specialized structures that have synaptic connections with sensory axons- taste buds, hair cells

Question 27

what does a stimulus do to a receptor

Answer 27

alters its permeability causing nonselective opening of all small ion channels leading to influx of na ions depolarizing membrane. graded local potential known as RECEPTOR POTENTIAL

Question 28

receptor potential

Answer 28

graded potential for one separate receptor- amp and duration can vary

Question 29

generator potential

Answer 29

graded potential in the case of the specialized ending of a nerve fibre- amp and duration can vary

Question 30

do receptor potential have a refractory period

Answer 30

no

Question 31

can receptor potentials haev summation

Answer 31

yes with rapidly successive stimuli

Question 32

tonic receptors

Answer 32

do not adapt or adapt slowly to sustained stimulation. muscle stretch receptors, joint proprioceptors

constant rate of depolarization

Question 33

phasic receptors

Answer 33

rapidly adapting receptors or sustained stimuli. tactile receptors in skin

burst of activity when stimulus is first applied then quicly decrease firing rate. exhibit off response

Question 34

somatosensory

Answer 34

1:1 association of receptor with a sensation- labelled line coding

Question 35

pathway for a detected modality

Answer 35

modality detected by a specialized receptor is sent over to a specific afferent and ascending pathway to excite a defined area in the somatosensory cortex. sensory info is mapped along specific pathways

Question 36

synesthesia

Answer 36

one sensation triggers another sensation

Question 37

receptive field

Answer 37

region of skin surface that the somatosensory neuron responds to

Question 38

acuity

Answer 38

the smaller the receptive field the greater the acuity- discriminative ability

Question 39

lateral inhibition

Answer 39

influences acuity

Question 40

sensory humonculus

Answer 40

represents a map of brain areas dedictaed to sensory processing for diff anatomical divisions of the body

Question 41

where is the primary sensory cortex located

Answer 41

postcentral gyrus

Question 42

what does the primary sensory cortex do

Answer 42

handles signals coming from the thalamus

Question 43

does a stronger receptor potential produce a larger action potential

Answer 43

no. it can induce a higher frequency firing of AP

Question 44

adaptation

Answer 44

reduction in receptor potentials despite sustained stimulation of the same magnitude. can be reduction in number of APs. helps prevent overload