MECEE-PG Nepal flashcards

32 cards. Read the term and the definition here. The deck at the top of this page is optional.

Erb palsy

Upper brachial plexus injury of C5 and C6 roots causing waiter's tip posture with the arm adducted, internally rotated, and the forearm pronated; commonly from birth trauma or shoulder dystocia.

Frank-Starling law

Stroke volume increases as ventricular end-diastolic volume increases, because greater stretch of myocardial fibres up to an optimum improves contractile force.

Rate-limiting enzyme of glycolysis

Phosphofructokinase-1 catalyses the committed step of glycolysis and is activated by AMP and fructose-2,6-bisphosphate while inhibited by ATP and citrate.

Caseating granuloma

A collection of epithelioid macrophages with central necrosis, classically seen in tuberculosis; non-caseating granulomas occur in sarcoidosis and Crohn disease.

Virchow triad

Three factors predisposing to thrombosis: endothelial injury, abnormal blood flow such as stasis or turbulence, and hypercoagulability of the blood.

Nephrotic syndrome

A renal syndrome defined by proteinuria above 3.5 g per day, hypoalbuminaemia, generalised oedema, and hyperlipidaemia, reflecting glomerular podocyte injury.

Zero-order kinetics

Drug elimination at a constant amount per unit time because metabolic enzymes are saturated; examples include ethanol, phenytoin, and high-dose aspirin.

Volume of distribution

A theoretical volume calculated as dose divided by plasma concentration; a large value indicates extensive tissue distribution and limited removal by dialysis.

Competitive antagonist

A drug that binds reversibly at the same receptor site as the agonist, shifting the dose-response curve rightward without reducing the maximal response.

Lancefield grouping

Classification of beta-haemolytic streptococci by cell-wall carbohydrate antigen; group A is Streptococcus pyogenes and group B is Streptococcus agalactiae.

HBeAg

A hepatitis B viral antigen indicating active viral replication and high infectivity; its presence supports consideration of antiviral therapy in chronic infection.

Ziehl-Neelsen stain

An acid-fast staining method using carbol fuchsin and acid-alcohol decolourisation; it detects mycobacteria such as Mycobacterium tuberculosis in sputum smears.

Diabetic ketoacidosis

A hyperglycaemic emergency with ketonaemia and high anion gap metabolic acidosis; total body potassium is depleted even when serum potassium appears normal.

Correction rate for hyponatraemia

Sodium should be corrected no faster than 8 to 10 mmol per litre in 24 hours to reduce the risk of osmotic demyelination syndrome.

Murphy sign

Inspiratory arrest during deep palpation below the right costal margin, indicating acute cholecystitis with an inflamed gallbladder contacting the examining hand.

Parkland formula

Burn resuscitation using 4 mL of Ringer lactate per kilogram body weight per percent total body surface area in 24 hours, half given in the first 8 hours.

Shock index

Heart rate divided by systolic blood pressure; a value above 0.9 suggests significant occult haemorrhage even when blood pressure still appears normal.

Naegele rule

Estimated delivery date calculated as the first day of the last menstrual period plus 7 days minus 3 months, assuming a regular 28-day cycle.

Placenta praevia

Placental implantation covering or near the cervical os, causing painless antepartum vaginal bleeding; digital vaginal examination is avoided until imaging excludes it.

Magnesium sulphate toxicity

Eclampsia treatment requiring monitoring of deep tendon reflexes, respiratory rate, and urine output; loss of reflexes, respiratory depression, and oliguria signal toxicity.

Apgar score

A neonatal assessment at 1 and 5 minutes scoring heart rate, respiratory effort, muscle tone, reflex irritability, and colour, each from 0 to 2.

Physiological jaundice

Neonatal jaundice appearing after the first 24 hours and peaking around days 3 to 5, caused by immature hepatic conjugation and increased bilirubin load.

Croup

Laryngotracheobronchitis causing a barking cough and inspiratory stridor in children, treated with dexamethasone and nebulised adrenaline for severe obstruction.

Koplik spots

Small white lesions on the buccal mucosa appearing before the measles rash; they are an early diagnostic sign of measles infection.

Incidence rate

The number of new cases of a disease divided by the population at risk, measured over a defined time period; it estimates disease risk.

Sensitivity

The proportion of people with disease who test positive, calculated as true positives divided by true positives plus false negatives.

Positive predictive value

The probability that a person with a positive test truly has the disease; it rises as disease prevalence in the tested population increases.

Herd immunity threshold

The proportion of a population needing immunity to interrupt transmission, approximated as 1 minus 1 divided by the basic reproduction number.

Glomerular filtration rate

The volume of plasma filtered by the kidneys per unit time; it depends on net filtration pressure and the filtration coefficient and is autoregulated.

Bohr effect

A rightward shift of the oxygen-haemoglobin dissociation curve caused by increased carbon dioxide, hydrogen ions, temperature, or 2,3-BPG, reducing oxygen affinity.

Michaelis constant Km

The substrate concentration at which an enzyme works at half its maximal velocity; a low Km indicates high affinity of the enzyme for substrate.

Alveolar ventilation

The volume of fresh air reaching alveoli per minute, calculated as respiratory rate multiplied by tidal volume minus anatomical dead space.