Unit 2, Part B: Posterior Paralleling, Radiation History and Production

Vocabulary practice flashcards covering terminology, exposure sequencing, radiation history, atomic physics, and x-ray production based on Unit 2, Part B lecture notes.

Radiology

The study of radiation.

Radiation

Forms of waves of energy emission through space or material.

X-radiation

High-energy, ionizing electromagnetic radiation.

Radiographs

Images that are either film-based or digitally produced, which are recordings of anatomic structures.

Radiographer

A trained and certified individual who exposes an anatomical area to ionizing radiation.

Posterior Periapical Receptor Placement Sequence

The exposure sequence starting with the maxillary right quadrant, moving to the mandibular left quadrant, then to the maxillary left quadrant, and finishing with the mandibular right quadrant.

Mandibular Premolar Receptor Placement

A technique modification where the receptor is placed under the tongue to reduce sensitivity and discomfort, with the lower edge gently softened.

Wilhelm Conrad Roentgen

The Bavarian physicist who discovered x-rays on November 8, $1895$, and was awarded the first Nobel Prize in physics in $1901$.

Crookes Tube

An early discharge tube used in early laboratory investigations of radiation.

Otto Walkhoff

The individual who made the first dental radiograph.

Dr. C. Edmund Kells

A New Orleans dentist credited with the first practical use of radiographs in dentistry in $1896$.

Energy

The capacity to do work.

Matter

Anything that occupies space and has form or shape.

Protons

Subatomic particles contained within the nucleus of an atom that carry positive electrical charges.

Neutrons

Subatomic particles contained within the nucleus of an atom that carry no electrical charge.

Electrons

Tiny negatively charged particles with very little mass that orbit around the nucleus of an atom.

Electron Shell

The designated orbit path of an electron surrounding an atomic nucleus.

Electron Binding Energy

The maintaining force that holds orbiting electrons in place around the nucleus, similar to gravitational attraction.

Photon

A minute bundle of pure energy that has no weight or mass.

Ion

An atom that has gained or lost an electron and become electrically unbalanced.

Ionization

The process where high-energy photons push an electron out of its orbit, creating an electrically unbalanced positive ion and an ejected negative electron.

Electromagnetic Radiation

Radiation composed of photons traveling through space at the speed of light in a straight line with a wavelike motion.

Wavelength

The distance from one wave crest to the next, determining the frequency and energy level of the x-ray.

Thermionic Emission

The release of an electron cloud resulting from heating the tungsten filament in the cathode using $3\text{ to }5\text{ V}$.

Cathode

The negative electrode in an x-ray tube containing a tungsten filament and molybdenum focusing cup.

Anode

The positive electrode in an x-ray tube containing a tungsten target that converts kinetic energy into x-ray energy and heat.

Aluminum Filter

A component in the x-ray tubehead that removes longer-wavelength, lower-energy x-rays from the primary beam.

Primary Radiation

The useful x-ray beam that originates directly from the target of the x-ray tube.

Secondary Radiation

X-radiation that is created when the primary beam interacts with matter.

Scatter Radiation

A form of secondary radiation that occurs when an x-ray beam is deflected from its trajectory by interaction with matter.

Radiolucent

Describing body structures that allow x-rays to pass through them, appearing dark or black on a radiograph (e.g., air spaces, soft tissues, pulp).

Radiopaque

Describing dense structures that do not allow x-rays to pass through them, appearing white or light gray on a radiograph (e.g., metal, enamel, dense bone).