Chpt. 4: *Light Flashcards
(35 cards)
What kind of light can cause harm?
sun burn, cutting laser, infra red radiation microwave, x-rays
What is the inverse relationship of light?
wavelength and frequency
-(if you have shorter wavelengths, you have larger frequency)
What are wavelengths measured in?
nanometers= visible light between 400-800 nm
*What are the two bands of UV light commonly used?
UV-A and UV-B
Define Reflection:
bouncing back of ray of light from energy source
Define Refraction:
Bending of energy; If the angle is not perpendicular, the light will be bent
Define absorption:
take-in light, or radiant energy
What is inverse relationship of absorption?
penetration
Who developed the Photoelectric Theory?
Einstein
What is Photoelectric theory?
a process whereby light falling on a surface knocks electrons out of the surface
What makes up all forms of light and is the elementary particle responsible for electromagnetic phenomena?
Photon
Define Photon
has no MASS, no charge and travels at speed of light
Why is full-spectrum light healthy for you?
(at noon)
-response reduces daily levels of melatonin and the stress hormone cortisol
*When daylight enters our eyes, it reaches the ____ and activates our ____ which is connected to our immune and nervous systems.
- pineal gland
- Endocrine system
What gland produces melatonin which is supposed to be related to immune system and disorders?
Pineal Gland (shaped like a cone)
What is the funciton of melatonin? (3)
- regulates daily body rhythms
- regulates circadian rhythm
- slow aging process
- coordninates fertility
What disorders is the pineal gland related to? (3)
- hypertension,
- epilepsy
- Paget’s disease.
What dermatologic condition has UV light been used as for treatment ?
psoriasis
UV-A has what type of wavelengths?
UV-B has what type of wavelengths?
Long wavelengths, low frequency
Short wavelengths, high frequency
-therefore greater absorption
Absorption depends on what from the source?
depends on distance
What two things need to be constance when using light as treatment?
intensity and distance
What are some contraindications for UV light treatment?
- photosensitive patients
- fever
- acute diabetes
What does LASER stand for?
Light Amplification by the Stimulated Emission of Radiation
What is Monochromatic ?
one wavelength= one colour
