UHS DES Entrance Exam flashcards

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

Median nerve injury

Carpal tunnel syndrome causes thenar wasting and loss of thumb abduction; the median nerve supplies the thenar muscles except adductor pollicis and the deep head of flexor pollicis brevis.

Inguinal canal boundaries

Anterior wall is external oblique aponeurosis, posterior is transversalis fascia reinforced by the conjoint tendon, roof is internal oblique and transversus, and floor is the inguinal and lacunar ligaments.

Femoral triangle contents

From lateral to medial lie the femoral nerve, artery, vein and lymphatics, within a triangle bounded by the inguinal ligament, sartorius and adductor longus.

Ureter constriction sites

Three natural narrowings where stones lodge are the pelviureteric junction, the crossing of the common iliac artery bifurcation, and the vesicoureteric junction as it enters the bladder.

Cardiac output and MAP

Cardiac output equals heart rate multiplied by stroke volume. Mean arterial pressure equals cardiac output times systemic vascular resistance, or diastolic pressure plus one third of pulse pressure.

Arterial oxygen content

Arterial oxygen content equals 1.34 times haemoglobin times saturation plus 0.003 times the partial pressure of oxygen; dissolved oxygen contributes little at normal atmospheric pressure.

Anion gap formula

The anion gap is sodium minus the sum of chloride and bicarbonate, normally 8 to 12 mmol/L; a raised gap suggests lactic acidosis, ketoacidosis, renal failure or toxin ingestion.

Glomerular filtration rate

GFR is the filtration coefficient multiplied by net filtration pressure, which is glomerular capillary hydrostatic pressure minus plasma oncotic pressure and capsular hydrostatic pressure.

Michaelis constant Km

Km is the substrate concentration giving half maximal velocity and is inversely related to enzyme affinity; a low Km means tight substrate binding at physiological concentrations.

Rate-limiting enzyme of glycolysis

Phosphofructokinase-1 converts fructose-6-phosphate to fructose-1,6-bisphosphate; it is inhibited by ATP and citrate and activated by AMP and fructose-2,6-bisphosphate.

HMP shunt function

The hexose monophosphate shunt produces NADPH for reductive synthesis and glutathione regeneration; glucose-6-phosphate dehydrogenase deficiency impairs this and causes haemolysis after oxidative stress.

Urea cycle rate-limiting enzyme

Carbamoyl phosphate synthetase I, activated by N-acetylglutamate, is rate-limiting; the cycle consumes four ATP and two nitrogen atoms to produce one urea molecule.

Virchow triad

Thrombosis results from endothelial injury, abnormal blood flow such as stasis or turbulence, and hypercoagulability; each limb of the triad is modified by different clinical risk factors.

Tumour suppressor gene loss

Tumour suppressor genes such as TP53 and retinoblastoma require loss of both alleles before function disappears, whereas oncogenes need only one activating mutation to drive proliferation.

Congo red amyloid

Amyloid deposits stained with Congo red show apple-green birefringence under polarised light; the misfolded beta-pleated sheet structure confers this property and is diagnostic on biopsy.

Zero-order kinetics drugs

In zero-order elimination a constant amount of drug is removed per unit time regardless of concentration, so half-life rises with dose; examples include ethanol, phenytoin and high-dose aspirin.

Volume of distribution

Volume of distribution equals dose divided by plasma concentration; large values indicate extensive tissue uptake, while small values indicate drug confined largely to plasma, as with warfarin.

Paracetamol antidote

N-acetylcysteine replenishes glutathione and detoxifies the reactive metabolite NAPQI; it is most effective when given within eight hours of ingestion and dosing is guided by the nomogram.

Staphylococcus aureus identification

Gram-positive cocci in clusters that are catalase positive and coagulase positive; coagulase converts fibrinogen to fibrin and distinguishes this organism from other staphylococci.

Hepatitis B serology

HBsAg indicates current infection, anti-HBs immunity, HBeAg high infectivity, and IgM anti-HBc acute infection; anti-HBc IgG persists lifelong as a marker of prior exposure.

Autoclave standard cycle

Steam sterilisation at 121 degrees Celsius and 15 pounds per square inch for 15 minutes kills spores; biological control uses Geobacillus stearothermophilus spores to verify the cycle.

Diabetes diagnostic criteria

Diabetes is diagnosed by fasting plasma glucose of 126 mg/dL or more, random or two-hour glucose of 200 mg/dL or more, or HbA1c of 6.5 percent or more.

CURB-65 components

Confusion, urea above 7 mmol/L, respiratory rate 30 or more, systolic pressure under 90 or diastolic 60 or under, and age 65 or older; each item scores one point.

Nephrotic syndrome criteria

Defined by proteinuria above 3.5 grams per day, hypoalbuminaemia below 3 g/dL, oedema and hyperlipidaemia; common causes include minimal change disease and membranous nephropathy.

Parkland burn formula

Give 4 mL of Ringer lactate per kilogram per percent of total body surface area burned over 24 hours, with half of the volume in the first eight hours from injury.

Indirect inguinal hernia

It passes through the deep ring lateral to the inferior epigastric vessels and travels within the spermatic cord; it is the commonest hernia in young males and may be congenital.

Postoperative fever timing

Timing suggests the cause: atelectasis and pneumonia early, urinary infection at three to five days, wound infection at five to seven days, deep vein thrombosis later, and drugs at any time.

Sepsis-3 definition

Sepsis is life-threatening organ dysfunction from a dysregulated host response, defined as a SOFA score rise of 2 or more; septic shock adds vasopressor need with lactate above 2 mmol/L.

Adult anaphylaxis adrenaline dose

Give 0.5 mg intramuscular adrenaline, which is 0.5 mL of a 1 in 1000 solution, into the anterolateral thigh and repeat every five minutes as required.

Adult CPR compression ratio

Compress the lower sternum at 100 to 120 per minute to a depth of 5 to 6 cm, allowing full recoil, with 30 compressions to 2 ventilations.

Sensitivity formula

Sensitivity is true positives divided by true positives plus false negatives, the proportion of diseased people correctly identified; highly sensitive tests suit screening and rule-out.

Herd immunity threshold

Herd immunity threshold equals one minus one divided by the basic reproduction number; it is the fraction of the population that must be immune to interrupt transmission.