Biophysics and Physical Principles Flashcards

This set of vocabulary flashcards covers concepts from Biophysics in Psychology, including brain imaging, eye anatomy, measurement standards, SI and derived units, uncertainty, significant figures, and vector/scalar physics.

Biophysics

The field that applies the theories and methods of physics to understand how biological systems work.

MRI (Magnetic Resonance Imaging)

A brain imaging technique used to visualize internal structures of the brain.

fMRI (functional MRI)

An imaging technique used for resting state analysis and mental imagery tasks.

MRA

Magnetic Resonance Angiography.

CT

Computed Tomography.

Accommodation

The process by which the eye focuses light; involving the rounding of the lens for close objects and flattening of the lens for distant objects.

Ciliary Muscle

The muscle that relaxes to focus on distant objects (flattening the lens) and contracts to focus on close objects (rounding the lens).

Measurement

The technique in which properties of an object are determined by comparing them to a standard quantity (units), translating properties into numbers.

Standard Units

Universally recognized units used for consistent measurement.

Non-Standard Units

Units used for less precise measurement that relies on societal knowledge.

Length

The measure of distance between two objects or points.

Volume

The measure of how much space something occupies.

Weight/Mass

The measure of the heaviness of an object or the amount of matter in an object.

Temperature

The measure of the degree of hotness or coldness of an object or substance based on a comparative scale.

English to Metric: Length

Conversion factors including $1\text{ mile} = 1.609\text{ km}$, $1\text{ ft} = 0.305\text{ m}$, and $1\text{ inch} = 2.54\text{ cm}$.

English to Metric: Mass

Conversion factors including $1\text{ lb} = 453.59\text{ g}$ and $1\text{ oz} = 28.35\text{ g}$.

Celsius to Kelvin Conversion

$0^\circ\text{C} = 273.15\text{ K}$.

Dimensional Analysis

The process of converting from one unit to another using conversion factors.

Fundamental SI Units

Units that cannot be expressed in terms of other units, including Mass, Length, Time, Current, Temperature, Amount of Substance, and Luminous Intensity.

Current

The flow of electrons from a high potential to a low potential.

Luminous Intensity

A measure of the amount of light that a point source radiates in a given direction.

Derived Units

Units formed as a combination (product or ratio) of two or more SI units, such as the Newton ($\text{kg}\times\text{m/s}^2$) or Pascal ($\text{N/m}^2$).

Type A Evaluation

A method of evaluating uncertainty through the statistical analysis of repeated measurements, often caused by random variations.

Type B Evaluation

A method of evaluating uncertainty using non-statistical methods or expert judgment, addressing systematic errors and instrument limitations.

Significant Figure Rule: Leading Zeros

Leading zeros do not count as significant digits (e.g., $0.000034$ has 2 significant digits).

Significant Figure Rule: Trailing Zeros

Trailing zeros count if there is a decimal point, but may not count if there is no decimal point (e.g., $190000$ is conservatively treated as 2 significant digits).

Scalars

Quantities defined solely by their magnitude, such as mass, time, energy, and speed.

Vectors

Quantities defined by both magnitude and direction, such as weight, velocity, and force.

Negative of a Vector

A vector having the same magnitude as the original vector but pointing in the opposite direction.

Tail to Head Method

A graphical method of adding vectors by placing the tail of the second vector at the head of the first and drawing a resultant vector from the start to the end.

Unit Vector

A vector that has a magnitude of $1$ and no units, used to describe a position in space.