Philippines PLE key terms

The body's tendency to keep internal conditions such as temperature, pH, and glucose within a narrow, workable range using feedback loops that sense change and trigger corrective responses.

A control mechanism in which the output of a process reduces the original stimulus, returning a variable toward its set point; most endocrine and autonomic regulation works this way.

The concentration of dissolved particles per kilogram of solvent, determining water movement across membranes; plasma osmolality normally sits near 275 to 295 milliosmoles per kilogram.

The pressure needed to stop net water movement across a semipermeable membrane separating solutions of different solute concentration; it drives fluid shifts between plasma and interstitial compartments.

The portion of plasma osmotic pressure contributed by proteins, mainly albumin, that holds water inside capillaries; low albumin lowers it and promotes edema.

The four pressures governing fluid exchange across capillary walls: capillary hydrostatic pressure, interstitial hydrostatic pressure, plasma oncotic pressure, and interstitial oncotic pressure.

A rapid, self-propagating change in membrane voltage produced by sequential sodium influx and potassium efflux through voltage-gated channels; it transmits signals along nerve and muscle fibers.

The steady voltage across a cell membrane at rest, typically about minus 70 millivolts in neurons, set mainly by potassium permeability and the sodium-potassium pump.

An energy-using membrane transporter that moves three sodium ions out and two potassium ions in per cycle, maintaining ion gradients and contributing to membrane voltage.

The brief interval after an action potential during which a neuron cannot fire again, or can fire only with a stronger stimulus, limiting signal frequency and ensuring one-way conduction.

The volume of blood pumped by one ventricle per minute, equal to heart rate multiplied by stroke volume; it is a central measure of circulatory performance and tissue perfusion.

The ventricular wall stretch at the end of filling, reflecting venous return and end-diastolic volume; within limits, greater preload increases stroke volume by the Frank-Starling mechanism.

The amount of blood ejected by a ventricle in a single contraction, determined by preload, afterload, and contractility; a typical adult value is about 70 milliliters.

The volume of plasma filtered by both kidneys per unit time, normally around 125 milliliters per minute; it is estimated clinically from creatinine and reflects functioning nephron mass.

A kidney autoregulatory mechanism in which the macula densa senses sodium chloride delivery and adjusts afferent arteriolar tone, stabilizing filtration despite changes in blood pressure.

A phospholipid mixture secreted by type II alveolar cells that lowers alveolar surface tension, preventing small air sacs from collapsing at the end of expiration.

The change in lung volume produced by a given change in transpulmonary pressure; low compliance means stiff lungs that require more effort to inflate.

The study of reaction rates catalyzed by enzymes, described by parameters such as Michaelis constant and maximal velocity, and used to characterize inhibition and substrate affinity.

The substrate concentration at which an enzyme works at half its maximal velocity; a low value indicates tight substrate binding and high affinity.

A reversible block in which an inhibitor resembling the substrate binds the enzyme's active site; it raises the Michaelis constant but leaves maximal velocity unchanged at high substrate.

The cytoplasmic pathway that splits one glucose into two pyruvate molecules, yielding two ATP and two NADH without oxygen; it is the entry point for both aerobic and anaerobic glucose use.

The mitochondrial sequence that oxidizes acetyl coenzyme A to carbon dioxide, generating reduced carriers NADH and FADH2 that feed the electron transport chain.

The mitochondrial process in which electrons passed along the respiratory chain pump protons, and the resulting gradient drives ATP synthase to make most cellular ATP.

The synthesis of glucose from non-carbohydrate precursors such as lactate, glycerol, and amino acids, occurring mainly in liver and kidney during fasting.

The breakdown of stored glycogen into glucose-6-phosphate, triggered by glucagon and epinephrine, which helps maintain blood glucose between meals.

Production of ketone bodies such as acetoacetate and beta-hydroxybutyrate from fatty acids in liver mitochondria, prominent during prolonged fasting or uncontrolled diabetes.

A metabolic acidosis caused by accumulation of ketone acids, seen in uncontrolled diabetes or starvation, marked by high anion gap, hyperglycemia, dehydration, and Kussmaul breathing.

The difference between nitrogen taken in through protein and nitrogen lost in urine, stool, and skin; a positive balance supports growth, while negative balance indicates catabolism or inadequate intake.

An amino acid the body cannot synthesize in adequate amounts and must obtain from diet; in adults these include leucine, isoleucine, valine, lysine, methionine, phenylalanine, threonine, and tryptophan.

A deficiency state from inadequate protein and calories, presenting as marasmus with severe wasting or as kwashiorkor with edema, low albumin, and relative preservation of fat.

Energy expended at complete rest, awake, and fasting, to maintain vital functions; it accounts for the largest share of daily energy use and is influenced by body size, age, and thyroid status.

Criteria linking a microbe to a disease: it must be found in all cases, be isolated and grown, reproduce disease when inoculated, and be recovered again from the experimental host.

Microorganisms that colonize skin and mucosal surfaces without causing disease, competing with pathogens for nutrients and space and sometimes causing infection when host defenses fail.

A microbe that rarely harms healthy hosts but causes disease when immunity is weakened or natural barriers are breached, such as Pseudomonas in neutropenia or burns.

The lowest antimicrobial concentration that visibly prevents growth of a standardized bacterial inoculum in vitro, used to guide susceptibility reporting and dosing decisions.

The lowest antimicrobial concentration that kills at least 99.9 percent of the starting bacterial population, determined by subculture after inhibitory testing.

Coordinated efforts to use antimicrobials only when indicated, at the right dose, duration, and route, to preserve effectiveness and limit resistance and adverse effects.

A bacterial enzyme that hydrolyzes the beta-lactam ring of penicillins and cephalosporins, inactivating them; inhibitor combinations such as clavulanate restore activity against many producers.

The ratio between a drug's toxic dose and its effective dose; a narrow index means small dose changes can cause toxicity, so plasma level monitoring is often needed.

The time required for plasma drug concentration to fall by half, governing how often a drug is dosed and how long effects persist after stopping.

A calculated apparent space relating total drug in the body to plasma concentration; a large value suggests extensive tissue uptake rather than confinement to blood.

Drug inactivation in gut wall and liver before reaching systemic circulation after oral dosing, which lowers bioavailability and can be avoided by parenteral routes.

Programmed cell death with cell shrinkage, chromatin condensation, and membrane blebbing, producing apoptotic bodies cleared without inflammation; it is energy-dependent and genetically regulated.

Uncontrolled cell death from severe injury, marked by swelling, membrane rupture, and inflammation; patterns include coagulative, liquefactive, caseous, and fat necrosis.

A reversible change in which one mature cell type is replaced by another better suited to stress, such as squamous change in smoker's airways; it is not itself malignant.

Disordered growth with variation in cell size, shape, and nuclear features and loss of normal orientation; it is precancerous and may progress to carcinoma in situ.

Autonomous new growth of cells that persists after the stimulus stops; benign tumors stay localized, while malignant ones invade and can spread to distant sites.

Spread of malignant cells from a primary tumor to distant organs through lymphatics, blood, or body cavities, where they implant and grow as secondary tumors.

A nodular collection of activated macrophages, often with multinucleated giant cells and a rim of lymphocytes, formed in chronic inflammation such as tuberculosis.

Abnormal accumulation of fluid in interstitial tissue or body cavities, arising from raised hydrostatic pressure, low oncotic pressure, lymphatic obstruction, or leaky capillaries.