Biophysics & Medical Physics
5 terms
Absorbed Dose
Biophysics & Medical Physics
Gy (Gray = J/kg)
The physical quantity measuring the amount of energy deposited by ionizing radiation per unit mass of matter.
D = dE / dm, 1 Gy = 1 J / kg = 100 rad
Action Potential
Biophysics & Medical Physics
mV (Amplitude ~100 mV) & m/s (Conduction Speed)
A rapid, self-propagating electrical voltage impulse along the membrane of excitable cells (neurons and muscle cells).
v_conduction ∝ √(d) (Unmyelinated), v_conduction ∝ d (Saltatory Myelinated)
Active Transport
Biophysics & Medical Physics
Ions/sec or μmol/min
The energy-requiring transport of ions or molecules across a biological cell membrane against their concentration gradient.
3 Na⁺_out + 2 K⁺_in per ATP Hydrolyzed (Sodium-Potassium Pump)
ALARA Principle
Biophysics & Medical Physics
Radiation Safety Protocol
A fundamental radiation protection safety principle stating that all radiation exposures must be kept 'As Low As Reasonably Achievable' (ALARA).
Dose Optimization: Minimize Time, Maximize Distance, Optimize Shielding
Audiometry
Biophysics & Medical Physics
dB HL (Decibels Hearing Level) & Hz
The clinical evaluation and quantitative measurement of human hearing sensitivity across pure tone sound frequencies.
Hearing Level dB HL = 20 log₁₀(P_measured / P_reference)