Philippines PLE flashcards

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

Frank–Starling law

Stroke volume increases with greater ventricular end-diastolic volume because stretching cardiac muscle raises contractile force, up to a physiologic limit beyond which further stretch decreases efficiency.

Glomerular filtration rate

Volume of plasma filtered by the glomeruli per minute, normally about 125 mL/min. It depends on filtration pressure and is estimated clinically by creatinine clearance.

Erb palsy

Brachial plexus injury involving C5–C6 roots, producing weakness of shoulder abduction and elbow flexion with the arm held in adduction and internal rotation.

Oxygen dissociation curve

Graph of hemoglobin oxygen saturation against partial pressure of oxygen. Rightward shift means reduced affinity and easier tissue unloading, caused by increased CO2, H+, temperature, or 2,3-BPG.

Diluting segment

Thick ascending limb of the loop of Henle, which reabsorbs sodium and chloride but is impermeable to water, producing dilute tubular fluid and contributing to the medullary concentration gradient.

Cardiac output formula

Cardiac output equals heart rate multiplied by stroke volume, normally about 5 L/min. The Fick principle estimates it from oxygen consumption divided by the arteriovenous oxygen difference.

Rate-limiting enzyme of glycolysis

Phosphofructokinase-1 catalyzes the committed step of glycolysis and is regulated by ATP, citrate, and AMP, making it the principal control point of glycolytic flux.

Pyruvate dehydrogenase complex

Multienzyme complex converting pyruvate to acetyl-CoA. It requires thiamine pyrophosphate, lipoic acid, coenzyme A, FAD, and NAD+; deficiency causes lactic acidosis and beriberi.

Urea cycle rate-limiting step

Carbamoyl phosphate synthetase I in liver mitochondria catalyzes the first and rate-limiting reaction, condensing ammonia with bicarbonate using two ATP molecules.

Essential amino acids

Nine amino acids that cannot be synthesized in adequate amounts and must come from diet: histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine.

Energy value of macronutrients

Carbohydrate and protein provide about 4 kcal per gram, fat provides 9 kcal per gram, and alcohol provides 7 kcal per gram. These values are used in dietary calculations.

Phenylketonuria mechanism

Deficiency of phenylalanine hydroxylase or its tetrahydrobiopterin cofactor causes phenylalanine accumulation. Untreated disease produces intellectual disability; treatment is dietary phenylalanine restriction with tyrosine supplementation.

Lead and heme synthesis

Lead inhibits aminolevulinic acid dehydratase and ferrochelatase, causing accumulation of aminolevulinic acid and protoporphyrin, producing microcytic anemia and basophilic stippling.

NADH ATP yield

Each NADH oxidized by the electron transport chain yields about 2.5 ATP, while each FADH2 yields about 1.5 ATP, giving roughly 30 to 32 ATP per glucose molecule.

Endotoxin structure

Lipopolysaccharide of the gram-negative outer membrane, composed of lipid A, core polysaccharide, and O antigen. Lipid A triggers fever and septic shock through Toll-like receptor 4.

Staphylococcus aureus identification

Gram-positive cocci in clusters that are catalase positive and coagulase positive. Coagulase positivity distinguishes it from coagulase-negative staphylococci such as S. epidermidis.

Acid-fast staining

Ziehl–Neelsen stain that retains carbol fuchsin in bacteria with mycolic acid in the cell wall, such as Mycobacterium tuberculosis, appearing red against a blue background.

Hepatitis B serology

HBsAg indicates infection, anti-HBs indicates immunity, HBeAg indicates high infectivity, and anti-HBc IgM indicates acute infection or the window period.

Plasmodium falciparum features

Most dangerous malaria species, causing severe disease with banana-shaped gametocytes, multiple ring forms in one red cell, and high parasitemia. Diagnosed by Giemsa-stained thick and thin smears.

Ascaris lumbricoides

Largest intestinal nematode, acquired by ingesting embryonated eggs. Larvae migrate through lungs causing Loeffler syndrome; adult worms may cause intestinal obstruction or biliary obstruction.

Dengue NS1 antigen

Nonstructural protein 1 detectable in serum during the first five days of dengue fever, before antibodies appear, making it useful for early diagnosis in acute infection.

Coagulative necrosis

Pattern of necrosis caused by ischemia in most organs except the brain, characterized by preservation of tissue architecture and loss of nuclei, with a pale firm appearance.

Granuloma formation

Collection of activated macrophages transformed into epithelioid cells, often with multinucleated giant cells, formed in chronic inflammation such as tuberculosis, sarcoidosis, and leprosy.

Virchow triad

Three factors predisposing to thrombosis: endothelial injury, abnormal blood flow such as stasis or turbulence, and hypercoagulability. All three contribute to venous and arterial thrombi.

Apoptosis features

Energy-dependent programmed cell death mediated by caspases, producing cell shrinkage, chromatin condensation, and apoptotic bodies without inflammation, unlike necrosis.

Tumor suppressor genes

Genes whose loss of function permits tumor development. Examples include RB in retinoblastoma, TP53 in Li–Fraumeni syndrome, APC in familial adenomatous polyposis, and BRCA1 in breast cancer.

Zero-order kinetics

Elimination at a constant amount per unit time because metabolic enzymes are saturated. Half-life varies with dose; examples include ethanol, phenytoin at high dose, and high-dose aspirin.

Volume of distribution

Apparent volume calculated as dose divided by plasma concentration. It estimates the extent of drug distribution into tissues and guides loading dose calculation.

CYP450 inducers

Drugs that increase cytochrome P450 activity and lower concentrations of coadministered substrates. Examples include rifampicin, carbamazepine, phenytoin, and St John's wort.

ACE inhibitor adverse effects

Cough from bradykinin accumulation, hyperkalemia, hypotension, angioedema, and acute kidney injury. Contraindicated in pregnancy and bilateral renal artery stenosis.

Paracetamol antidote

N-acetylcysteine replenishes hepatic glutathione and detoxifies the reactive metabolite NAPQI. It is most effective when given within eight to ten hours of overdose.

Informed consent elements

Valid consent requires patient capacity, adequate disclosure of risks and alternatives, comprehension of the information, and voluntariness, documented in the medical record before the procedure.