NS V Sensory Physiology

Question 1

where do afferent pathways enter the spinal cord

Answer 1

through the posterior/dorsal root

Question 2

what does the dorsal column pathway send info about

Answer 2

touch pressure proprioception

Question 3

what does the spinothalamic tract send info about

Answer 3

pain and temperature

Question 4

where does the dorsal column pathway cross over

Answer 4

lower medulla

Question 5

where does the spinothalamic tract cross over

Answer 5

at the spinal cord

Question 6

what neuron is the one that always crosses over

Answer 6

the second order neuron

Question 7

what are the 5 types of sensory receptors

Answer 7

-mechanoreceptors
-chemoreceptors
-thermoreceptors
-nociceptors
-photoreceptors

Question 8

what do mechanoreceptors receive info about and where are they found

Answer 8

info about compression/stretch
- found in skin, muscle spindles, hearing, equilibrium, arterial pressurer

Question 9

what do chemoreceptors signaled by

Answer 9

ligands

Question 10

what are nociceptors signaled by

Answer 10

damage

Question 11

the particular form of energy to which a receptor is most sensitive is called its _____?

Answer 11

adequate stimulus

Question 12

what does activation of sensory receptors cause

Answer 12

change in membrane potential called transduction and produces a graded potential

Question 13

what type of receptor is a pacinian corpuscle

Answer 13

mechanoreceptor

Question 14

what does a larger graded potential lead to

Answer 14

larger number of APs

Question 15

what is the relationship between increase in stimulus strength and graded potentials

Answer 15

direct but not linear

Question 16

what is the intensity of stimulus determined by

Answer 16

the frequency of APs (temporal summation) and the total number of receptors activated (spatial summation)

Question 17

what is adaptation

Answer 17

when stimulus is maintained the frequency of APs decreases over time

Question 18

where can adaptation occur

Answer 18

at the receptor or in the neuron

Question 19

what is tonic vs phasic

Answer 19

tonic adapts slow phasic adapts fast

Question 20

what happens in receptor adaptation

Answer 20

decrease in amplitude of graded potential over time in the presence of a constant stimulus

Question 21

what do tonic receptors help differentiate

Answer 21

stimulus intensity

Question 22

what do phasic receptors help differentiate

Answer 22

duration

Question 23

what are examples of tonic receptors

Answer 23

, nociceptors, baroreceptors, chemoreceptors

Question 24

what are examples of phasic receptors

Answer 24

pacinian corpuscle

Question 25

what is the labeled line principle

Answer 25

a precise type of stimulus activates specific receptors and postsynaptic cells. the info continues on a pathway that specific kinds of information are conveyed by specific nerve fibers to specific regions of the CNS that are programmed for perception of that modality

Question 26

what does the homonculus do

Answer 26

correlates the anatomical regions of the CNS with where interpretation and awareness of sensations are perceived

Question 27

where do second to third order neurons synapse

Answer 27

at the thalamus

Question 28

what is a receptive field

Answer 28

region where a single fibers afferent receptors are located

Question 29

what is the effect of overlap in receptive fields

Answer 29

it improves localization ability

Question 30

what is acuity

Answer 30

precision with which a stimulus is perceived

Question 31

what does lateral inhibition do

Answer 31

enhances acuity

Question 32

how does lateral inhibition work

Answer 32

it decreases lateral spread of an excitatory signal and increases degree of contracts in the sensory pattern perceived in the cortex

Question 33

where does lateral inhibition occur

Answer 33

at each synapse, medulla, thalamus and cerebral cortex

Question 34

what is the conduction velocity and type of information transmitted by A alpha fibers

Answer 34

fast -muscle spindle, muscle tendon, skeletal muscle

Question 35

what is the conduction velocity and type of information transmitted by A betafibers

Answer 35

fast -muscle spindle, hair receptors, vibration, high discrimination touch, deep pressure, skeletal muscle

Question 36

what is the conduction velocity and type of information transmitted by A gamma fibers

Answer 36

fast -deep pressure and touch, pricking pain

Question 37

what is the conduction velocity and type of information transmitted by A delta fibers

Answer 37

fast -deep pressure and touch , pricking pain

Question 38

what is the conduction velocity and type of information transmitted by C fibers

Answer 38

slow - crude touch and pressure, tickle, aching pain, cold and warmth

Question 39

what are the types of mechanoreceptors

Answer 39

-free nerve endings - pacinian corpuscles

Question 40

what is the function and location of free nerve endings and what type of adaptation

Answer 40

function: detect touch and pressure (temp and pain) location: skin, cornea, dental pulp, GI tract -slow/tonic

Question 41

what is the function, location, and type of adaptation of pacinian corpuscles

Answer 41

function: detect deep pressure, vibration location: subcutaneous tissue, viscera, joints -rapid/phasic

Question 42

what type of vibration is detected by pacinian corpuscles? meisnners?

Answer 42

pacinian- higher frequency meissners: lower frequency

Question 43

what spinal pathway detects vibration

Answer 43

dorsal column pathway

Question 44

what is the function, location, and type of adaptation of meissners corpuscles?

Answer 44

function: detect light, touch, pressure and vibration location: glabrous skin -rapid/phasic

Question 45

what is the function, location, and type of adaptation of merkels discs

Answer 45

function: localize continuous pressure and sensing an objects texture location: all skin slow/tonic

Question 46

what is the function, location, and type of adaptation of ruffini's endings

Answer 46

function: sensitive to stretch or indentation; proprioception location: deep layers of skin, joints, surrounding tooth roots -slow/tonic

Question 47

what are the receptors in the periodontal ligament

Answer 47

mechanoreceptors that are ruffini-like receptos

Question 48

what is the function, location, and type of adaptation of hair end organ

Answer 48

function: hair movement location: base of hair follicle -rapid/phasic

Question 49

what side of the spinal cord does the ascending sensory tract ascend the spinal cord in the dorsal column pathway

Answer 49

same side as the stimulus

Question 50

what side of the spinal cord does the ascending sensory tract ascend the spinal cord in the spinothalamic pathway

Answer 50

opposite side of the stimulus

Question 51

what are the proprioception receptor types

Answer 51

-photoreceptors -touch and pressure receptors in skin, joints, ligaments (periodontal ligament) -skeletal muscle receptors -vestibular receptors

Question 52

what are examples of skeletal muscle receptors

Answer 52

-muscle spindles -golgi tendon organs