CORRECT ANSWERS 2024/2025
Define radiation - ANSWERSa form of energy carried by waves or a stream of particles
Steps to produce x-rays - ANSWERS1: x-ray machine on
2: current travels from control panel to the tubehead
3: current directed to filament circuit and step-down transformed in the tubehead. 110/120v to 3-5v
4: filament current uses 3-5 to heat tungsten filament in cathode portion of x-ray tube
5: exposure button pushed - activates high voltage current - electrons are accelerated from cathode
across x-ray towards anode
6: electrons strike tungsten target and kinetic energy converted to x-ray energy and heat
7: heat produced and carried away from copper stem and absorbed by insulating oil in tubehead
8: x-rays travel through unleaded glass window, tubehead seal, and aluminum disks
9: size of the x-ray beam restricted by lead collimator
10: beam travels down lead lined PID and exits tubehead at opening of PID
How do x-rays differ from light? - ANSWERSThe light waves are visible and each color has a different
wavelength. X-rays are invisible and have shorter wavelengths and a higher frequency.
Low-voltage circuit is controlled by what setting? - ANSWERSmA
High voltage circuit is controlled by what setting? - ANSWERSkV
What allows for greater penetration of xrays? - ANSWERSx-ray beam quality and shorter wavelengths
caused by the increased kVp allow for greater penetration
Hired the first dental assistant as an "escort" and introduced the paralleling technique (XCPs) -
ANSWERSC. Edmund Kells
, What kind of radiation do dental x-rays produce? - ANSWERSelectromagnetic radiation
Focal spot (tungsten target) - ANSWERSthe area of the anode surface which receives the beam of
electrons from the cathode; converts bombarding electrons into x-ray photons, concentrating the
electrons or creating an enormous amount of heat
What controls the speed of the electrons? - ANSWERSVoltage determines the speed/energy of electrons
Lymphocytes (blood)
GI tract
Bone
Nerves
LILY GOES BOUNCING NORTH - ANSWERSOrder of most sensitive to least sensitive to ionizing radiation
Radiosensitive (most sensitive) cells - ANSWERSblood cells, immature reproductive cells, young bone
cells, small lymphocytes (most sensitive out of group)
What is secondary radiation? - ANSWERSx-radiation that is created when a primary beam interacts with
matter; it is less penetrating than primary radiation
kVp - ANSWERSWhat determines the energy of photons?
What increases the quantity of generated x-rays? - ANSWERSmilliamperage (mA) and exposure time are
inversely related and have a direct influence on the number of electrons produced.
(When mA is increased, exposure time is decreased and vice versa)
What stops x-rays the most? - ANSWERSlead