Surgery Flashcards
What nerves innervate the conchal bowl?
CNVII, IX, X
A ring block around the entire ear will numb the whole thing except:
concha AND external auditory canal
Innervation of the majority of the posterior ear
Greater auricular nerve
What nerve is damaged in Frey syndrome?
Auriculotemporal nerve (a branch of the mandibular nerve)
Frey syndrome is also called auriculotemporal nerve syndrome which is facial flushing, sweating in response to gustatory stimuli - usually and injury of the parotid nerve
What chemical does Botox prevent the release of?
Acetylcholine from the presynaptic terminal
Which part of the Botox protein binds to SNAP25? Heavy chain or light chain?
Light chain
What does the heavy chain of Botox do?
Binds to the axon terminal
SNAP25 is what type of protein?
A SNARE Protein
Which serotypes is SNAP/SNARE cleaved by? (A-E)
A & E
VS VAMP which is cleaved by B,D,F,G
Which type of neurotransmitter does Botox block - sympathetic or nonsympathetic?
Acetylcholine so it is sympathetic
Property of lasers in which the light waves travel in PHASE together
Coherence
Vs collimation which means the light waves travel in parallel. Together these two properties give a laser its ability to be precise
Property of lasers in which light waves travel in parallel to each other
Collimation
The emission of ONE well-defined wavelength, rather than a band or variety of wavelength
Monochromicity
What is the Fresnel reflectance property?
The property of skin that causes 4-7% of light to be reflected because of the difference in the refractive index of the stratum corneum and the Aires
What is the absorption coefficient in the skin? And what does it depend on
The absorption coefficient is the probability of a photon being ABSORBED (rather than reflected or scattered) by its target chromophore. And it depends on the CONCENTRATION OF CHROMOPHORES present
Name the three primary skin chromophores
Water, melanin, hemoglobin
Name the spectrum of light that melanin absorbs photons in?
Broadly across the visible and UV spectrum
Name the spectrum of light that hemoglobins absorb photons in?
UV, and specifically green, blue, and yellow regions
Name the spectrum of light that Water absorbs photons in?
Infrared spectrum
Name the spectrum of light that the chromophores absorb photons in:
Melanin
Hemoglobin
Water
Melanin - Broad UV, Visible light
Hemoglobin - UV, Green, Blue, Yellow
Water - Infrared
Name the wavelengths of the most deeply penetrating lasers
650-1200nm
What is the cut-off wavelength when a laser switches from being deep penetrating to superficial
1200nm
The least penetrating wavelengths are within which spectrum?
Far Infrared and far UV spectrums
Two most superficially penetrating lasers
Erbium Yag
CO2 laser
Which type of collagen gets melted during laser therapy?
Type I collagen
Definition of thermal relaxation time
The time it takes a heated tissue to cool to HALF of its original temperature
What is the relationship between the size of a tissue and it’s thermal relaxation time
Thermal relaxation time is equal to the square of the target dimension (in millimeters)
The optical pulse duration in photothermolyis is equal to what:
The Thermal relaxation time (TRT)
Name the two most common continuous wave lasers (vs pulsed)
Argon and NG:YAG
Peak absorption of oxyhemoglobin
577nm (within yellow spectrum)
Wavelength of PDL laser
560-600nm
*b/c PDLs are used to treat vascular lesions, and oxyhemoglobin’s peak absorption spectrum is 577nm
Deepest penetrating laser and its absorption wavelength
Nd:YAG 1064nm
Wavelength of PDL laser
560-600nm
Wavelength of Nd:YAG laser
1064nm (deepest penetrating laser, good for dermal vessels)*
Wavelength of Alexandrite laser
755nm
Best kind of lasers for treating pigmented lesions and tattoos
Q switched lasers (like Q-switched Ruby and Alexandrite)
Q-switched ruby & Alexandrite lasers are useful for removing what kind of lesions?
Pigmented nevi & black/green tattoo pigment
Deep black tattoos and dermal melanocytic nevi (like Nevus of Ota) are best treated with which laser?
Q switched Nd:YAG
Q switched Nd:YAG laser is used to treat what
Deep black tattoos (Dermal involvement)
&
Dermal melanocytosis (like Nevus of Ota)
*b/c Nd:YAG laser is 1064nm, the deepest penetrating, down to dermis
Which laser creates thousands of micro thermal treatment zones in the epidermis and dermis
Fraxel (fractional photothermolysis)
How does Fraxel work?
Creates thousands of microthermal treatment zones
Highest risk of blindness with which kind of lasers
Near-Infrared Q-switched lasers
What kind of media is a PDL laser?
Liquid media (rhodamine dye)
Name two lasers with Gas media?
CO2 laser Xenon chloride (excimer laser)
To achieve selective photothermolyis, do you want your pulse duration to be less than or greater than your thermal relaxation time (TRTs)?
You want you pulse duration to be LESS THAN your TRT
Continuous laser is low or high power?
Continuous laser is low power, pulsed laser is high power