Somatosensory System Flashcards
What sense is detected in the somatosensory system?
Touch
Choose the best option
The somatosensory system (does/does not) have a single receptor sheet where the somatosensory information is transduced.
Does not
Where can you find Somatosensory receptors?
They can be found throughout the body.
Located on our:
Skin Surfaces
Muscle Joints
Internal Organs
There are several different types of somatosensory receptors which transduce different ________ of somatosensory sensation.
Modalities
What are the three characteristics of the different types of somatosensory receptors?
Different mechanisms of transduction
Different types of axons
carry information to the brain by different pathways
Looking at this figure
Which one(s) of these cells are mechanoreceptors, a sense organ or cell that responds to mechanical stimuli such as touch or sound?
Meissner Corpuscle
Ruffini’s corpuscles
Merkel’s discs
Pacinian corpuscle
True or False: Free Nerve Endings, Somatosensory Receptors, all look the same anatomically but have four different functions.
True
True or False: Free Nerve Endings have different sensitivities due to molecular (not cellular) specializations.
True
What are the two types of Free Nerve Ending Receptors?
Thermoreceptors, transducing changes in temp.
Nociceptors, transducing pain
What are the two types of thermoreceptors Free Nerve Ending Receptors?
Cold Receptors
Hot Receptors
What do Cold receptors respond to?
Respond to sudden decreases in temp. adapted , the cold feeling will go away, over the course of a few seconds
Choose the best option
Cold receptors have (small/large) diameter (unmyelinated/ myelinated) axons. The A.P. travel at medium velocity
Small ; Myelinated
What pathway does the cold information take to send to the brain?
Spinothalamic Pathway
What is the other type of Thermoreceptors?
Hot Receptors
What do Hot Free Nerve Ending receptors respond to?
They respond to sudden increases in temp. adapt over the courses of a few seconds.
Choose the best option
Hot receptors have (small/large) diameter, (myelinated, unmyelinated) axons.
The A.P. travel at a slow velocity
Small ; Unmyelinated
What pathways do the hot receptors send information to the brain?
Spinothalamic Pathway
Nociceptors
What is nociception?
Where does it arise from?
The perception of noxious or damaging stimuli (ex: cut in the skin)
Arises from a combination of direct and indirect action on the peripheral sensors.
This include:
painful heat
Acid
Chemical activators such as ATP and bradykinin released from skin damage
What are the two types of Nociceptors receptors?
Sharp Pain Receptors
Burning Pain Receptors
For Sharp Pain receptors, what stimuli do they respond to?
They respond to stimuli causing a sharing force on the skin such as cuts or bruises.
Choose the best option
Sharp pain receptors have a (small/large) diameter (thinly/heavily) myelinated axons.
The axons fibers are Ad group, meaning that the A.P. travel at medium velocity.
Small ; Thinly
Where do the sharp pain receptors send their information to the brain?
Spinothalamic pathways
For Buring pain receptors, what kind of stimuli does it respond to?
Respond to many painful stimuli including damaging heat, sharp blow, and noxious chemicals.
Choose the best option
Bruning pain receptors have a very (small/large), (myelinated/ unmyelinated) axon.
The axon fibers are C fiber groups.
A.P. travel at a slow velocity
Small; unmyelinated
Where do burning pain receptors send information to the brain?
Thru the spinothalamic pathways
What kind of channel are the hot and cold receptors?
TRP (Transient Receptor Potential) Channels
Temp. changes are transduced by free nerve ending through the activation of TRP ion channels.
What are the structural components of TRP channels?
TRP channels are composed of 6 putative membrane-spanning units and cytoplasmic N- and C- termini
TRPV 1 to TRPV 4 are activated over different _______ ranges.
Warm Temp.
TRPM8 is a Ca2+ permeable channel activated by _________.
Lower temp
TRP can also be activated by _________ stimulations.
TRPV1 is also sensitive to __________
TRPM8 is also sensitive to _________ and ___________.
Non- temp.
Capsaicin
Methol and eucalyptol