PMC Residency Entrance Exam key terms

The principle that stretching cardiac muscle fibres with greater filling volume increases the force of contraction, so stroke volume rises with preload up to a physiological limit.

The ventricular wall stretch at end-diastole, determined mainly by venous return and blood volume, and estimated clinically by central venous pressure or echocardiographic filling assessment.

The volume of blood ejected by one ventricle per minute, calculated as stroke volume multiplied by heart rate, normally about five litres at rest in adults.

The difference between measured serum sodium and the sum of chloride and bicarbonate, used to classify metabolic acidosis as high-gap or normal-gap and to guide further testing.

A primary fall in plasma bicarbonate producing low blood pH, caused by acid accumulation, bicarbonate loss, or impaired renal acid excretion, and compensated by hyperventilation.

Life-threatening circulatory failure from infection, defined by persistent hypotension requiring vasopressors to maintain mean arterial pressure despite adequate fluid resuscitation, with raised serum lactate.

A clinical sign in which the examiner's hand pressing below the right costal margin elicits an inspiratory arrest during deep breathing, suggesting acute cholecystitis.

Pain felt in the right lower quadrant when the left lower quadrant is palpated, produced by gas displacement within the colon, and classically associated with acute appendicitis.

Inflammation of the peritoneum, presenting with board-like abdominal rigidity, rebound tenderness, and guarding; may be primary, or secondary to a perforated or ischaemic viscus.

Torsion of a bowel loop around its mesenteric axis, causing closed-loop obstruction and risk of strangulation; sigmoid and caecal types produce characteristic radiological appearances.

New hypertension after twenty weeks of gestation with proteinuria or other organ dysfunction, reflecting widespread endothelial injury and carrying risk of seizures and placental insufficiency.

The occurrence of generalised tonic-clonic seizures in a woman with preeclampsia, without another identifiable cause, requiring urgent magnesium sulphate treatment and delivery planning.

A severe pregnancy complication marked by haemolysis, elevated liver enzymes, and low platelets, often accompanying preeclampsia and threatening maternal and fetal survival.

A numerical score of cervical dilatation, effacement, consistency, position, and fetal station used to predict the likelihood of successful induction of labour.

Yellow discolouration of skin and sclera from bilirubin accumulation in the first weeks of life; physiological forms appear after twenty-four hours, while earlier or rapidly rising jaundice needs investigation.

Permanent neurological injury from bilirubin deposition in the basal ganglia and brainstem of a newborn, causing hypotonia, deafness, choreoathetosis, and impaired upward gaze.

A rapid newborn assessment at one and five minutes scoring heart rate, respiratory effort, muscle tone, reflex irritability, and colour, each from zero to two.

The functional unit of the kidney, comprising a glomerulus and its tubule, which filters plasma and modifies the filtrate by selective reabsorption and secretion.

The volume of plasma filtered by both kidneys per unit time, normally near 125 millilitres per minute, and used clinically to stage chronic kidney disease.

The net movement of water across a semipermeable membrane from a region of lower solute concentration to one of higher solute concentration, driven by an osmotic pressure gradient.

A model describing enzyme rate as a saturable function of substrate concentration, defined by the maximum velocity and the substrate concentration giving half that velocity.

Reversible enzyme inhibition in which an inhibitor resembling the substrate binds the active site, raising the apparent Michaelis constant while maximum velocity remains unchanged at high substrate concentration.

Programmed cell death with cell shrinkage, chromatin condensation, and membrane blebbing, producing apoptotic bodies removed without inflammation, in contrast with necrosis.

Irreversible cell injury causing swelling, membrane rupture, and leakage of contents that provokes inflammation; classified as coagulative, caseous, fat, fibrinoid, or liquefactive by tissue pattern.

The lowest concentration of an antimicrobial agent that prevents visible growth of a standardised bacterial inoculum, used to define susceptibility and resistance.

An enzyme produced by some bacteria that hydrolyses the beta-lactam ring of penicillins and cephalosporins, abolishing their activity; inhibitor combinations such as clavulanate restore efficacy.

Indirect protection of susceptible individuals that arises when a sufficient proportion of a population is immune, reducing transmission and interrupting outbreaks.

The number of new cases of a disease arising in a defined population during a specified period, divided by the population at risk.

The proportion of a population that has a disease at a given point or over a period, reflecting both incidence and duration of illness.

The probability that a test is positive in a person who truly has the disease, calculated as true positives divided by all those with disease.

The probability that a test is negative in a person who truly does not have the disease, calculated as true negatives divided by all those without disease.

The probability that a person with a positive test result actually has the disease; it depends on disease prevalence as well as on test sensitivity and specificity.

An acute, fluctuating disturbance of attention and awareness with altered cognition, usually caused by physical illness, drugs, or withdrawal, and distinct from dementia.

A chronic, progressive decline in two or more cognitive domains sufficient to impair daily function, with preserved consciousness, commonly due to Alzheimer disease or vascular pathology.

A severe psychiatric emergency beginning within weeks of childbirth, marked by mood disturbance, confusion, and delusions, carrying high risk of suicide and infanticide.

Postmortem stiffening of muscles from depletion of adenosine triphosphate, beginning in small muscles within hours and resolving after roughly one to three days.

Postmortem purplish discolouration of dependent skin caused by gravitational settling of blood, useful for estimating time since death and for detecting body repositioning.

The gradual cooling of a body after death toward ambient temperature, used with other findings to estimate the postmortem interval.

A patient's voluntary agreement to an intervention after receiving adequate information about its nature, risks, benefits, and alternatives, given while mentally competent.

The ethical and legal duty to keep patient information private, disclosable only with consent or where law or overriding public interest permits.

A tuning-fork test comparing air conduction with bone conduction; normal hearing gives air conduction louder, while conductive loss reverses this pattern.

A tuning fork placed on the midline of the forehead or vertex; sound lateralises to the ear with conductive loss and away from the ear with sensorineural loss.

Bilateral optic disc swelling from raised intracranial pressure, causing blurred disc margins, venous engorgement, and transient visual obscurations, usually with preserved visual acuity.

An anaesthetic technique using a fast-acting induction agent and neuromuscular blocker with cricoid pressure to secure the airway quickly and reduce aspiration risk.

A bedside grading of visible oropharyngeal structures with the mouth open and tongue protruded, used to predict difficulty of laryngoscopy and tracheal intubation.

A calibrated measure of radiodensity on computed tomography, with water at zero, air near minus one thousand, and bone in the high positive hundreds.