Ultrasound and Radiation Physics Quiz

The range of frequencies where human ears are most sensitive, typically between 2000 Hz and 5000 Hz.

Represents the threshold of human hearing, meaning the quietest sound we can perceive. It's not the absence of sound, but the minimum sound level we can detect.

The subjective quality of sound that allows us to distinguish different instruments or voices, even if they play the same note at the same loudness. It's determined by the mix of harmonics and overtones in the sound wave.

The perceived highness or lowness of a sound, primarily determined by the frequency of the sound wave. Higher frequencies correspond to higher pitches.

The relationship between the intensity of a sound wave and its perceived loudness. It states that the perceived loudness grows logarithmically with the intensity of the sound.

The power of a sound wave per unit area. It's a measure of the energy carried by the sound wave.

The property of a material that determines how much sound is transmitted or reflected at a boundary. It's calculated by multiplying the density of the material by the speed of sound in that material.

Measured in decibels (dB), it represents the intensity level of a sound wave. It's a logarithmic scale used to compare the loudness of different sounds.

The change in frequency of a wave due to the relative motion between the source and the observer.

The ability of sound waves to pass through a medium.

The measurement of the difference in the ultrasonic wave frequencies emitted and received by a transducer. This difference reveals information about the movement of blood cells and other structures.

The ability of certain materials to generate an electrical signal when subjected to mechanical stress, and vice versa.

Ultrasound with frequencies below the range of human hearing.

The use of ultrasound to deliver medications or other substances into the body.

The ability of ultrasound waves to penetrate tissue depends on the frequency of the ultrasound. Lower frequency waves (e.g., 3 MHz) penetrate deeper than higher frequency waves (e.g., 20 MHz).

The speed of sound in a medium depends on the properties of that medium. Different tissues have different densities and elasticity, which affects how sound travels through them.

The use of high-frequency sound waves (above 20 kHz) to create images of internal structures in the body.

The change in frequency of a wave (like ultrasound) due to the relative motion of the source and observer. Used to measure blood flow.

A medical procedure using high-energy sound waves to break down kidney stones without damaging surrounding tissues.

Mechanical waves that travel through a medium by compressing and expanding the particles of the medium.

Ultrasound waves in the human body are longitudinal, meaning the particles vibrate parallel to the direction the wave travels.

Certain tissues, like collagen, in the human body exhibit piezoelectric properties, meaning they generate electrical charges in response to mechanical stress.

The time it takes for a wave to complete one full cycle.

Alternating current changes direction with time.

Negatively charged particles responsible for electric current flow in metals.

The minimum energy required to remove an electron from a material.

The relationship between voltage, current, and resistance in a circuit.

The rate of change of electric charge over time.

The instrument used to measure and display the relationship between voltage and time.

The SI unit of electric current, representing one coulomb of charge per second.

Movement of solvent (like water) through a semipermeable membrane, from a region of lower solute concentration to a region of higher solute concentration. In simpler terms, water moves from where there's less dissolved stuff to where there's more dissolved stuff.

The process of removing excess water and waste products from the blood using a dialysis machine, which acts as an artificial kidney.

A solution with a higher solute concentration than the blood, which is essential for drawing out excess water from the blood during hemodialysis.

A type of conductivity in semiconductors where positively charged 'holes' act as the primary charge carriers. It's created by doping a semiconductor with a group III element, like Boron.

A type of conductivity in semiconductors where negatively charged electrons are the primary charge carriers. It's created by doping a semiconductor with a group V element, like Phosphorus.

A process where a high-energy photon interacts with an atom, causing the emission of an electron and a positron.

The most common interaction between radiation and tissue (mostly water) for energies between 60 keV and 10 MeV. It involves the scattering of a photon by an electron, resulting in a change in direction and energy of the photon.

The unit used to measure the amount of energy absorbed per unit mass of material. It's defined as 1 joule of energy absorbed per kilogram of mass.

Gamma rays have higher penetration power and cause less damage near the surface allowing for targeted treatment of deep tumors.

Electron beams are well-suited for treating surface and skin tumors because their energy decreases rapidly with depth, delivering most of their dose to the desired area.

The unit used to measure the biological effect of radiation on living organisms. It accounts for the type of radiation and the sensitivity of the tissue.

A measure of the ionization produced in air by X-rays or gamma rays. It's expressed as the amount of electric charge produced per unit mass of air.

Radiation composed of charged particles, like electrons, protons or alpha particles, which interact directly with matter.