Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
43 Cards in this Set
- Front
- Back
|
how does the brain make sense of touch?
|
transduces so neuron can understand it (ISPS or ESPS). The transduction sends an intercelluar signal to the CNS
|
|
|
define stimulus
|
physical energy that activates the receptor.
|
|
|
how does transduction occur
|
ransduces to intercellular signal via opening ion channels, switching on second messenger systems sends signal to CNS so we know our arm has been touched.
|
|
|
what are the 4 sensory receptors?
|
chemoreceptor
mechanoreceptor photoreceptor thermoreceptor |
|
|
Define adequate stimuli
|
any of the 4 sensory receptors that the stimuli is most responsive to
|
|
|
define transduction
|
converting physical signals into intercellular signals that the CNS can understand
|
|
|
define threshold
|
minimum amount of stimuli needed to activate EPSP or IPSP
|
|
|
define graded potential
|
change in the membrane potential in response to the stimulus
|
|
|
define ESPS
|
depolarization, bring M.P. closer to threshold for A.P.
|
|
|
define ISPS
|
inhibitory, increasing M.P. further from threshold from A.P.
|
|
|
define receptor potential
|
produced when receptor is activated by its adequate stimulus and above threshold. Changes in M.P. in response to the stimulus.
|
|
|
What are the steps in the pathway to the cortex?
|
Primary S.N. has sensory receptors in it, transduce stimulus
send signal to second S.N. send signal to thalamus send signal to the cortexx |
|
|
where does fine touch decussate?
|
in the medulla
|
|
|
where does pain/temp decussate?
|
in the spinal cord
|
|
|
who am I?
Mechanical stimuli- vibration deep in dermis large receptive field rapidly adapting |
Pacinian corpuscles
|
|
|
who am I?
mechanical stimli-stretching deep in dermis lg. receptive field slowly adapting? |
Ruffini
|
|
|
who am I?
mechanical-flutter/ stroke located in the fingertips small receptive fields slowly adapting |
Meissners
|
|
|
Who am I?
mechanical- steady pressure and texture superficial layers of the skin small receptive field slowly adapting |
Merkel's disc
|
|
|
who am I?
located around hair roots and under skin surface responds to various stimuli variable adaptation |
free nerve endings
|
|
|
define two point discrimination
|
the minimum distance necessary to differentiate between two points touching the body simultaneously
|
|
|
what is the function of primary afferent neurons?
|
to carry sensory signals to the brain
|
|
|
where do primary afferent neurons enter the spinal cord?
|
through the dorsal roots.
|
|
|
where are the cell bodies located that are associated with primary afferent axons?
|
in the dorsal root ganglion
|
|
|
what are the three different types of sensory nerve fibers?
|
A beta
A delta C |
|
|
who am I?
thick fastest conducting signal MYLENATED heavily sensory- mechanoreceptors in the skin |
A beta
|
|
|
who am I?
medium thickness medium speed lighly myelinated sensory- cold, fast pain, mechanical stimuli |
A delta
|
|
|
who am I?
thin layer slowest conducting signal no myelination sensory- slow pain, heat, cold, mechanical stimuli |
C
|
|
|
where is the somatosensory cortex in the brain?
|
the parietal lobe
|
|
|
what is the somatosensory cortex also known as?
|
post-central gyrus
|
|
|
what are the brodmann area's associated with the somatosensory cortex?
|
1, 2, 3a, 3b
|
|
|
what is located at brodmann area 3b ?
|
primary somatosensory cortex
|
|
|
what is the somatotropic map a map of?
|
the somatosensory cortex
|
|
|
what does each portion of the somatosensory cortex represent?
|
a different part of the body. The amount of space given to each part is correlated to how sensitive it is.
|
|
|
define cortical map plasiticity
|
cortical maps are dynamic and adjust depending on the amount of sensory experience
|
|
|
who am I?
feel pain, free nerve endings in the skin. These nerve endings respond to noxious stimuli, or potentially damaging stimuli to the tissue |
Nociceptor
|
|
|
Nociceptor channels open b/c of what chemical signals?
|
ATP, K+, Bradykinin
|
|
|
what are the 4 different nociceptors?
|
polymodal
mechanical thermal chemical |
|
|
what is the really neat thing about vanilloid R?
|
it can detect heat from temperature and from hot sauce
|
|
|
what sensory nerve fiber am I ?
I feel the initial pain? |
A delta
|
|
|
what sensory nerve fiber am I?
slow itch, pain |
C
|
|
|
what is the gate-control theory of pain?
|
painful stimulus is trying to send info to the brain, its trying to switch of the inhibitory interneuron. At the same time you give a mechanical non-painful stimulus, this info is given by A beta fibers switches inhibitory back on. It can override the C fibers to shut off the inhibitory
|
|
|
what do prostoglandins do?
|
shut off the COX pathway
|
|
|
who is safer, cox 1 or cox 2?
|
cox 2, we need cox 1 to be switched on so we dont have GI bleeding
|
