Lecture 8 Flashcards
(9 cards)
What is leprosy?
Results in continuous injuries, infections, etc.
What is shingles and what is it caused by?
A section of skin that has a burning or stabbing pain, hypersensitivity, inflamed and blistered skin, and a scaly appearance, it is commonly only on one side of the body and it is caused by the chicken pox virus that lays dormant in the dorsal root ganglion cells and reactivates.
What is a phantom limb?
Where amputees believe that their amputated limb is still there, and they have extreme pain in their phantom limb
What is telescoping?
Where an amputee believes that the phantom limb is getting shorter, for example their phantom arm is getting closer to their shoulder.
What are the three basic types of somatosensations?
1) touch and pressure on the skin
2) pain and temperature
3) limb orientation and posture
What are the three types of mechanoreceptors?
Slowly Adapting (SA)- these respond best to pressure, and will fire more action potentials with increasing pressure on the skin Rapidly-Adapting (RA)- these respond to transients in pressure, and will respond to the onset and offset of pressure to the skin, they can phase lock stimuli in the range of 5-40 Hz Pacinian/vibratory- these respond best to very high frequencies and will phase lock in the range of 40-350 Hz
What is a peri-stimulus time histogram (PSTH)
a common way of showing how a neuron responds by action potentials
What happens when something presses against the skin?
Opens stretch channels, which will let anything cross the membrane (Na+, K+, Ca++, etc), thus the membrane potential will be driven down to 0 mV
What makes the RA and PC receptors different than the SA regarding stretch channels?
RA and PC have structures around the stretch channels that will absorb the change in skin and let the stretch channel relax back to the closed position even if the skin is still depressed.
