FCPS Part-1 flashcards

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

Resting membrane potential

The electrical potential across a neuron membrane at rest, about −70 mV, set mainly by potassium permeability and the Na⁺/K⁺-ATPase pump maintaining ion gradients.

Frank–Starling relationship

Within physiological limits, increased ventricular end-diastolic volume (preload) stretches myocardial fibers and increases stroke volume, matching cardiac output to venous return.

Hardy–Weinberg equation

p² + 2pq + q² = 1 describes genotype frequencies in a large randomly mating population without selection or mutation, where p and q are allele frequencies.

Autosomal recessive inheritance

Two carrier parents have a 25% chance per pregnancy of an affected child, 50% of a carrier child, and 25% of an unaffected non-carrier child.

Transport maximum

The maximum rate a carrier-mediated reabsorptive process can achieve when all transporters are saturated, as with renal glucose reabsorption at roughly 375 mg/min.

Inulin clearance

Inulin is freely filtered and neither secreted nor reabsorbed, so its clearance equals glomerular filtration rate; it is the reference standard for measuring GFR.

Henderson–Hasselbalch equation

pH = 6.1 + log([HCO₃⁻] / (0.03 × PaCO₂)); it relates bicarbonate and carbon dioxide to blood pH and underpins acid–base interpretation.

Volume of distribution

Apparent volume relating total body drug amount to plasma concentration (Vd = dose / concentration); large values indicate extensive tissue distribution rather than plasma binding.

Drug half-life

Time for plasma concentration to fall by half, calculated as 0.693 × Vd / clearance; about four to five half-lives are needed to reach steady state.

Loading dose formula

Loading dose = (Vd × target plasma concentration) / bioavailability; it rapidly fills the distribution volume before maintenance dosing sustains the target concentration.

Cerebrospinal fluid glucose

Normal CSF glucose is roughly 60% of simultaneous blood glucose; a ratio below 0.4 strongly suggests bacterial or fungal meningitis.

Osmotic demyelination risk

Overly rapid correction of chronic hyponatremia can cause central pontine demyelination; correction should not exceed 8–10 mmol/L in 24 hours.

Effective renal plasma flow

Para-aminohippurate is filtered and avidly secreted, so its clearance approximates effective renal plasma flow; renal blood flow equals this divided by (1 − hematocrit).

X-linked recessive inheritance

A carrier mother transmits the allele to 50% of sons, who are affected, and 50% of daughters, who are carriers; affected fathers pass it only to daughters.

Enzyme kinetics Km

The Michaelis constant is the substrate concentration producing half-maximal reaction velocity; a low Km indicates high enzyme affinity for substrate.

Primary PCI window

In ST-elevation myocardial infarction, primary percutaneous coronary intervention should be delivered within 90 minutes of first medical contact, or 120 minutes if transfer is needed.

Life-threatening asthma

Features include silent chest, cyanosis, exhaustion, SpO₂ below 92%, peak flow under 33% predicted, and a normal or rising PaCO₂ signaling fatigue rather than improvement.

Thrombolysis time window

Intravenous alteplase for acute ischemic stroke is generally given within 4.5 hours of symptom onset, after non-contrast CT excludes intracranial hemorrhage.

DKA insulin endpoint

In diabetic ketoacidosis, continue intravenous insulin until ketones and acidosis resolve, not merely until glucose normalizes; add dextrose when glucose falls to maintain insulin delivery.

Sepsis definition

Sepsis is life-threatening organ dysfunction caused by a dysregulated response to infection, operationalized as a SOFA score rise of two or more points.

Septic shock criteria

Sepsis with persisting hypotension requiring vasopressors to maintain mean arterial pressure ≥ 65 mmHg despite adequate fluid resuscitation, with serum lactate above 2 mmol/L.

Bacterial meningitis empiric therapy

Adults receive immediate ceftriaxone plus vancomycin, with ampicillin added when Listeria is a concern; dexamethasone before or with the first dose reduces hearing loss.

Glasgow–Blatchford score

A pre-endoscopy score using urea, hemoglobin, systolic pressure, heart rate, and clinical features to identify upper GI bleed patients who need intervention or admission.

Variceal bleed management

Suspected variceal hemorrhage is treated with a vasoactive drug (terlipressin or octreotide), prophylactic antibiotics, restrictive transfusion, and endoscopy within 12 hours.

Acute pancreatitis diagnosis

Requires two of three features: characteristic epigastric pain radiating to the back, serum lipase or amylase above three times the upper limit, and imaging findings.

Hyperkalemia ECG changes

Progressive peaked T waves, PR prolongation, loss of P waves, and QRS widening; severe cases need intravenous calcium, insulin with glucose, and salbutamol.

Nephrotic syndrome triad

Heavy proteinuria above 3.5 g/day, hypoalbuminemia, and edema with hyperlipidemia; minimal change disease is the commonest cause in children.

Acute epiglottitis features

Fever, sore throat, muffled voice, drooling, and tripod positioning in a toxic child; airway examination is deferred to senior staff and the airway secured urgently.

Preeclampsia diagnostic criteria

New hypertension after 20 weeks with proteinuria or other end-organ features such as renal, hepatic, neurological, or hematological dysfunction; delivery is the definitive treatment.

Diabetic foot osteomyelitis

Suspect when a foot ulcer probes to bone or a toe is swollen and erythematous; MRI and bone biopsy guide diagnosis, and prolonged antibiotics often follow debridement.

Pulmonary embolism diagnostic pathway

Use a validated clinical probability score; low probability with a negative D-dimer excludes embolism, while high probability proceeds to CT pulmonary angiography.

Atrial fibrillation stroke prevention

Estimate thromboembolic risk with CHA₂DS₂-VASc; anticoagulation is recommended at a score of 2 or more in men and 3 or more in women.

Cushing reflex

Hypertension with bradycardia and irregular respiration signals raised intracranial pressure with brainstem compromise, requiring urgent decompression and airway control.