Question High voltage pulses (> 50 v) applied to skin increase its permeability
ID: 3478746 • Letter: Q
Question
Question
High voltage pulses (> 50 v) applied to skin increase its permeability to large molecular weight, hydrophilic permeants in a remarkable manner clearly distinct from low voltage iontophoresis. Name the mechanism by which this permeability increase is thought to occur.
No unique mechanism is implied. Most materials respond this way.
The stratum corneum acts as a semiconductor.
The lipids surrounding the corneocytes in the bulk stratum corneum are electroporated.
The phospholipids lining the skin appendages (sweat glands and sebaceous glands) are electroporated.
Convective flow through the sweat ducts is stimulated.
Question
The DC current-voltage characteristic of human skin is non linear at voltages above about 0.25 v, i.e. current (i) increases much faster than voltage (v). The dependence is approximately exponential. Name a mechanism that could account for this phenomenon for voltages in the range 0.25 < v < 4 volts.
No unique mechanism is implied. Most materials respond in this way.
The stratum corneum acts as a semiconductor.
The lipid bilayers surrounding the corneocytes in the bulk stratum corneum are electroporated.
The phospholipids lining the appendageal cell membranes (sweat gland and sebaceous gland) are electroporated.
Convective flow through the sweat ducts is stimulated.
Question
The GlucoWatch Biographer (TM) elicited glucose levels at the skin surface based on what physical principle?
sonophoresis
iontophoresis
electroporation
electro-osmosis
radio-frequency ablation
a.No unique mechanism is implied. Most materials respond this way.
b.The stratum corneum acts as a semiconductor.
c.The lipids surrounding the corneocytes in the bulk stratum corneum are electroporated.
d.The phospholipids lining the skin appendages (sweat glands and sebaceous glands) are electroporated.
e.Convective flow through the sweat ducts is stimulated.
Explanation / Answer
Question 1- The third option-c is correct. It is the only present reason of skin’ nature for High voltage pulses, which is by electroporation of the stratum corneum though its intracellular lipid bilayers.
Question 2- The second option is correct. It is the nature of human skin, works as semiconductor for DC current. That causes increase in current.
Question 3- The fourth option- d is correct. It is the transportation process, electro-osmosis, which helps in high molecular weight cations and transporting uncharged molecules.
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