Homeostasis, Neuroscience, and Biomedical Engineering Lecture Notes

A comprehensive set of vocabulary flashcards covering basic physiology, neuroscience, immunology, regulatory standards, and medical ethics.

Homeostasis

The process by which the body maintains a stable internal environment despite external changes.

Negative Feedback

A mechanism that occurs when a deviation from a set point triggers responses that reverse that deviation.

Antagonistic Negative Feedback

A process involving two opposing effectors where one increases a variable while the other decreases it, such as the regulation of blood glucose by insulin and glucagon.

Acids

Substances that donate hydrogen ions ($H^+$).

Bases

Substances that accept hydrogen ions or release hydroxide ions ($OH^-$).

pH

The negative logarithm of hydrogen ion concentration, defined as $\text{pH} = -\log[H^+]$.

Buffers

Systems, such as the bicarbonate system, that resist changes in pH by shifting equilibrium reactions to maintain blood pH between $7.35$ and $7.45$.

Hodgkin–Huxley Model

A model that describes how action potentials are generated by treating the membrane as an electrical circuit with capacitance and conductance, involving sodium influx and potassium efflux.

GLP

Good Laboratory Practice; regulations governing laboratory research practices to ensure reliable data.

GMP

Good Manufacturing Practice; regulations that ensure consistent and safe manufacturing processes for medical devices.

510(k) Process

An FDA regulatory pathway that demonstrates a medical device is substantially equivalent to an existing device.

PMA

Premarket Approval; a requirement for high-risk devices involving extensive clinical testing.

Resting Membrane Potential

The baseline electrical potential of a neuron, measured at approximately $-70\,mV$.

Action Potential Threshold

The depolarization level, approximately $-55\,mV$, required to trigger an action potential.

Depolarization

The phase of an action potential caused by the opening of sodium channels and the subsequent influx of $Na^+$.

Repolarization

The phase of an action potential caused by the opening of potassium channels and the subsequent efflux of $K^+$.

Refractory Periods

Time intervals that ensure one-way signal propagation along a neuron.

Frontal Lobe

The region of the cerebrum that controls motor function, decision-making, and personality.

Parietal Lobe

The region of the cerebrum that processes sensory information such as touch and pressure.

Temporal Lobe

The region of the cerebrum responsible for hearing and memory.

Occipital Lobe

The region of the cerebrum that processes visual information.

REM Sleep

A stage of sleep characterized by dreaming, high brain activity, and muscle paralysis.

Schwann Cells

Cells in the peripheral nervous system that enable the regeneration of neurons.

Long-Term Potentiation (LTP)

The process of strengthening synapses through repeated stimulation, which underlies learning and neuroplasticity.

Cardiac Cycle Phases

A sequence of four events: ventricular filling, isovolumetric contraction, ejection, and isovolumetric relaxation.

SA Node

The part of the heart's electrical system that initiates the heartbeat.

AV Node

The part of the heart's electrical system that delays the signal to allow for ventricular filling.

P Wave

The portion of an ECG representing atrial depolarization.

QRS Complex

The portion of an ECG representing ventricular depolarization.

T Wave

The portion of an ECG representing ventricular repolarization.

fMRI

Functional Magnetic Resonance Imaging; a technique that measures brain activity indirectly through the BOLD signal (blood oxygenation changes).

Innate Immunity

A fast and non-specific immune response that serves as the body's primary defense.

Adaptive Immunity

A slower, highly specific immune response that includes memory and improves upon repeated exposure.

Phagolysosome

The structure formed when a phagosome fuses with a lysosome to digest pathogens.

Inflammation

A process characterized by redness, heat, swelling, and pain, caused by vasodilation and increased vascular permeability.

T Cells

Cells maturing in the thymus that mediate cellular immunity, including helper and cytotoxic functions.

B Cells

Cells maturing in the bone marrow that produce antibodies and mediate humoral immunity.

Antigens

Foreign substances that trigger an immune response.

Antibodies

Proteins that bind specifically to antigens to neutralize or destroy them.