9 Applied Biophysics in Medicine Free Online FlashCards

What does applied biophysics connect?

Applied biophysics connects physical laws to living systems and clinical care, helping detect disease, guide treatment, and operate biomedical devices.

What does Hooke’s law relate in an elastic material?

For small deformations, Hooke’s law is $F=kx$, where $F$ is force, $x$ is displacement, and $k$ is stiffness.

How does vessel radius affect resistance in Poiseuille’s relation?

For ideal laminar flow through a rigid cylindrical tube, $R=\frac{8\eta L}{\pi r^4}$. The fourth-power dependence means a modest decrease in radius can greatly raise resistance.

What drives flow through vessels and airways?

A pressure difference drives flow through vessels and airways; resistance depends on fluid properties and passage geometry.

How does a ventilator help move air into the lungs?

A ventilator applies pressure to move air through the airways and expand the lungs. Clinicians monitor pressure and airflow to limit unnecessary mechanical stress.

What is the goal of radiotherapy treatment planning?

High-energy radiation damages cellular DNA. Treatment planning aims to deliver the prescribed dose to a target while limiting exposure of nearby healthy tissue.

What does one gray measure?

The absorbed dose is measured in grays $Gy$; $1\,\mathrm{Gy}=1\,\mathrm{J/kg}$.

What biological activity does an ECG detect?

An electrocardiogram (ECG) records the heart’s changing electrical activity using electrodes placed on the skin.

How does a pacemaker support the heart?

A pacemaker uses electrical pulses to stimulate the heart when its natural rhythm needs support.

How do echoes help form an ultrasound image?

Ultrasound uses high-frequency sound; echo travel time helps estimate depth, and echo strength contributes to image brightness. It provides real-time imaging without ionizing radiation.

What does Doppler ultrasound measure in moving blood?

Doppler ultrasound measures the frequency shift of sound reflected by moving blood cells. The shift depends on flow velocity and the angle between the beam and blood flow.

What signals does MRI use to create images?

MRI combines strong magnetic fields and radiofrequency energy. Signals from hydrogen nuclei in body water and fat are used to form detailed images, especially of soft tissue.