Category
Physiology
Body function, regulation and systems physiology.
Subcategories
Cardiac cycle, output, blood pressure and circulatory control.
RespiratoryVentilation, lung volumes, gas exchange and transport.
RenalFiltration, tubular handling, concentration and clearance.
GastrointestinalSecretion, motility, digestion and absorption.
EndocrineHormones, axes and feedback control.
NeurophysiologyMembrane potentials, synapses, sensory and motor pathways.
Muscle and ExerciseMuscle contraction, fibre types and the response to exercise.
Blood and ImmunityHaemostasis, haemoglobin, blood groups and immune function.
Acid-Base and FluidsAcid-base balance, buffers, osmolality and fluid compartments.
Cellular and MetabolicMembrane transport, cell signalling, energy and temperature.
ReproductiveMenstrual cycle, pregnancy, lactation and reproductive hormones.
Entries in Physiology
Duodenum for iron and calcium, jejunum for most nutrients, ileum for B12 and bile salts
A memory aid for where each nutrient is absorbed.
Respiratory Opposite, Metabolic Equal
A mnemonic to remember the relationship between pH and primary values in acid-base disorders.
Check pH, then carbon dioxide, then bicarbonate, then compensation, then the anion gap
A memory aid for a systematic approach to blood gas interpretation.
Acral and soft tissue overgrowth with metabolic and mass effects
A memory aid for the clinical features of growth hormone excess.
Depolarisation by sodium influx, repolarisation by potassium efflux, then hyperpolarisation
A memory aid for the phases of the neuronal action potential.
Prerenal, intrinsic renal and postrenal
A mnemonic for classifying acute kidney injury by site.
A modified sympathetic ganglion secreting adrenaline and noradrenaline into the blood
A memory aid for catecholamine synthesis and action.
Cholesterol to mineralocorticoids, glucocorticoids and androgens
A memory aid for the three branches of adrenal steroid synthesis.
Alpha-1 vasoconstricts, beta-1 stimulates the heart, beta-2 vasodilates
A memory aid for the cardiovascular actions of each adrenoceptor subtype.
Aortic pressure, systemic vascular resistance, ventricular radius and wall thickness
A memory aid for the factors setting ventricular afterload.
Arteries stiffen, diastolic function declines, and maximum heart rate falls
A memory aid for the normal cardiovascular changes of ageing.
Nephron loss with falling GFR, reduced concentrating ability and blunted responses
A memory aid for the normal renal changes of ageing.
Loss of elastic recoil, stiffer chest wall, rising closing capacity and falling oxygen tension
A memory aid for the normal respiratory changes of ageing.
Gas is fully saturated at body temperature by the time it reaches the isothermic boundary
A memory aid for how inspired gas is conditioned.
Medium-sized bronchi contribute most resistance, not the smallest airways
A memory aid for where airway resistance is greatest and what alters it.
Sodium in, potassium and hydrogen out, at the distal nephron
A memory aid for the renal actions of aldosterone.
11-beta-hydroxysteroid dehydrogenase inactivates cortisol in mineralocorticoid target tissues
A memory aid for how the kidney distinguishes aldosterone from cortisol.
Inspired oxygen minus carbon dioxide divided by the respiratory quotient
A memory aid for calculating alveolar oxygen tension.
Alveolar carbon dioxide is inversely proportional to alveolar ventilation
A memory aid for the relationship between ventilation and carbon dioxide.
A normal gradient points to hypoventilation or low inspired oxygen; a wide gradient points to lung disease
A memory aid for interpreting the A-a gradient.
Type 1 is excess synthesis; type 2 is destructive thyroiditis
A memory aid for the two forms of amiodarone-induced thyrotoxicosis.
Gut-derived ammonia is converted to urea by the liver; failure allows it to reach the brain
A memory aid for ammonia metabolism and hepatic encephalopathy.
Microcytic, normocytic and macrocytic, each with a short differential
A memory aid for classifying anaemia by red cell size.
Bronchial and thebesian veins drain deoxygenated blood into the systemic circulation
A memory aid for the normal physiological shunt.
Sodium minus chloride and bicarbonate, normally 8 to 16 mmol per litre
A memory aid for calculating and interpreting the anion gap.
The kidney adjusts bicarbonate over days to offset a change in carbon dioxide
A memory aid for renal compensation of respiratory acid-base disorders.
Growth hormone, prolactin, ACTH, TSH, FSH and LH
A memory aid for the six anterior pituitary hormones and their targets.
FSH, LH, ACTH, TSH, Prolactin, Insulin-like (IGF), GH
A mnemonic for the six hormones secreted by the anterior pituitary gland.
Warfarin blocks vitamin K, heparin activates antithrombin, DOACs block Xa or thrombin
A memory aid for how the anticoagulants work and are monitored.
Antithrombin, protein C and S, and tissue factor pathway inhibitor
A memory aid for the body's own anticoagulant systems.
It inserts aquaporin-2 channels into the collecting duct
A memory aid for how vasopressin concentrates the urine.
Water retention through V2 receptors and vasoconstriction through V1 receptors
A memory aid for the cardiovascular actions of vasopressin.
Immature respiratory control with a paradoxical response to hypoxia
A memory aid for why premature infants stop breathing.
Apoptosis is programmed and tidy; necrosis is accidental and inflammatory
A memory aid for distinguishing the two forms of cell death.
Ghrelin stimulates hunger; leptin, PYY and GLP-1 promote satiety
A memory aid for the hormones controlling hunger and satiety.
Diffuse alveolar damage causes non-cardiogenic oedema, shunt and stiff lungs
A memory aid for the physiology of acute respiratory distress syndrome.
Bronchoconstriction, gas trapping and hyperinflation with V/Q mismatch
A memory aid for the physiological changes in acute asthma.
Adenosine triphosphate
A high-energy molecule used as a cellular energy currency.
Glycolysis, the Krebs cycle and oxidative phosphorylation
A memory aid for the stages of cellular energy production.
Sinoatrial node 60 to 100, atrioventricular junction 40 to 60, ventricle 20 to 40
A memory aid for the intrinsic rates of the cardiac pacemakers.
Chronotropy, inotropy, dromotropy and lusitropy
A mnemonic for the four autonomic actions on cardiac function.
Sympathetic is thoracolumbar with short pre and long postganglionic fibres; parasympathetic is craniosacral and the reverse
A memory aid for the differences between sympathetic and parasympathetic systems.
Myogenic and metabolic mechanisms hold flow steady despite changing pressure
A memory aid for the mechanisms keeping organ blood flow constant.
Antigen binding plus T cell help drives class switching and affinity maturation
A memory aid for how B cells mature and change antibody class.
Bainbridge speeds the heart with atrial stretch; Bezold-Jarisch slows it
A memory aid for two cardiac reflexes with opposite effects on heart rate.
Carotid sinus and aortic arch stretch receptors adjust autonomic outflow within seconds
A memory aid for the short-term regulation of blood pressure.
The direct pathway facilitates movement; the indirect pathway inhibits it
A memory aid for the direct and indirect basal ganglia pathways.
Energy expenditure at rest, mainly determined by lean body mass
A memory aid for basal metabolic rate and what alters it.
Base excess quantifies the metabolic component independently of carbon dioxide
A memory aid for the derived metabolic acid-base parameters.
Bile salts, phospholipids, cholesterol, bilirubin and bicarbonate
A memory aid for what bile contains and what it does.
High red cell turnover with immature conjugation and enterohepatic recycling
A memory aid for why newborns become jaundiced.
Unconjugated bilirubin is conjugated in the liver, excreted in bile, and converted to urobilinogen
A memory aid for the pathway of bilirubin from haem to stercobilin.
Group O is the universal red cell donor; group AB the universal plasma donor
A memory aid for the ABO and Rhesus systems.
Viscosity rises steeply with haematocrit, so optimal delivery occurs at an intermediate value
A memory aid for how haematocrit affects flow and oxygen delivery.
About 70 per cent in the venous system, 15 per cent arterial, 5 per cent capillary
A memory aid for how blood volume is distributed around the circulation.
Tight junctions between endothelial cells, supported by astrocyte foot processes
A memory aid for the structure and significance of the blood-brain barrier.
Bicarbonate in extracellular fluid, haemoglobin in blood, protein and phosphate in cells, bone in chronic acidosis
A memory aid for the main physiological buffers.
Total body water 60 per cent, two-thirds intracellular, one-third extracellular
A mnemonic for the distribution of body water.
Bohr is carbon dioxide affecting oxygen carriage; Haldane is oxygen affecting carbon dioxide carriage
A mnemonic for distinguishing the Bohr and Haldane effects.
Bone remodels along lines of stress, according to Wolff's law
A memory aid for how bone responds to mechanical load.
Osteoblasts build, osteoclasts resorb, coupled through RANK ligand
A memory aid for the hormonal control of bone turnover.
Blood pressure
The pressure exerted by circulating blood on arterial walls.
Colostrum first, then transitional and mature milk
A memory aid for lactogenesis and the composition of breast milk.
Rising carbon dioxide is the main stimulus, with falling oxygen contributing later
A memory aid for what terminates a breath hold.
Histamine and leukotrienes early, cellular infiltration late
A memory aid for the mediators of the early and late asthmatic response.
WiLLiaM MaRRoW: left gives W in V1 and M in V6; right gives M in V1 and W in V6
A mnemonic for distinguishing right from left bundle branch block.
Mostly passive in the proximal tubule and loop, actively regulated in the distal tubule
A memory aid for renal calcium reabsorption and its control.
Parathyroid hormone and vitamin D raise calcium; calcitonin lowers it
A memory aid for the three hormones controlling calcium.
Diffusion for gases, bulk flow for water, vesicular transport for large molecules
A memory aid for how substances cross the capillary wall.
Amylase to oligosaccharides, brush border enzymes to monosaccharides, then transport
A memory aid for the steps of carbohydrate digestion and absorption.
Bicarbonate about 70 per cent, carbamino about 23 per cent, dissolved about 7 per cent
A memory aid for the three forms in which carbon dioxide is carried.
It binds haemoglobin 240 times more avidly than oxygen and shifts the curve left
A memory aid for why carbon monoxide is so dangerous.
All Points Reach Plateau, Restore
A mnemonic for the five phases of the ventricular cardiac action potential.
Both positive is normal; leads pointing away from each other indicate deviation
A memory aid for working out the cardiac axis from leads I and aVF.
Atrial systole, isovolumetric contraction, ejection, isovolumetric relaxation, then filling
A memory aid for the seven phases of the cardiac cycle.
Cardiac muscle is a functional syncytium with a long refractory period and cannot tetanise
A memory aid for the differences between cardiac and skeletal muscle.
Preload, Rate, Stroke volume, Heart contractility
A mnemonic for the four main determinants of cardiac output.
Cardiac output equals heart rate multiplied by stroke volume
A memory aid for calculating cardiac output and its normal values.
Fick principle, indicator dilution, thermodilution, Doppler and pulse contour analysis
A memory aid for the methods of measuring cardiac output.
Absolute refractory period prevents tetany; the relative period allows vulnerable re-excitation
A memory aid for the absolute and relative refractory periods of cardiac muscle.
Equalisation of diastolic pressures with impaired filling and pulsus paradoxus
A memory aid for the haemodynamics of cardiac tamponade.
Pressure work is far more costly in oxygen than volume work
A memory aid for the components of cardiac work.
Immediate tachycardia and hyperventilation, then polycythaemia and pulmonary hypertension
A memory aid for the circulatory adaptations to high altitude.
Cardiac output rises, resistance falls, and flow is redistributed to muscle
A memory aid for the circulatory changes during dynamic exercise.
Low inspired oxygen, hypoventilation, diffusion impairment, V/Q mismatch, shunt
A mnemonic for the five mechanisms of arterial hypoxaemia.
Raised hydrostatic pressure, low oncotic pressure, increased permeability, lymphatic obstruction
A mnemonic for the mechanisms of oedema formation.
Simple and facilitated diffusion, primary and secondary active transport, and vesicular transport
A memory aid for the ways substances cross cell membranes.
Ion channel, G protein coupled, enzyme linked and intracellular receptors
A memory aid for the main types of cell surface receptor.
It reflects right atrial pressure, which depends on volume, cardiac function and compliance
A memory aid for what central venous pressure does and does not tell you.
DANISH: Dysdiadochokinesia, Ataxia, Nystagmus, Intention tremor, Slurred speech, Hypotonia
A mnemonic for the signs of cerebellar dysfunction.
Carbon dioxide is the most powerful cerebral vasodilator
A memory aid for the factors controlling cerebral perfusion.
Frontal for motor and executive, parietal for sensation, temporal for hearing and memory, occipital for vision
A memory aid for the main functional areas of the cortex.
Produced by choroid plexus, circulates through the ventricles, absorbed by arachnoid granulations
A memory aid for CSF production, circulation and absorption.
Peripheral chemoreceptors sense oxygen; central chemoreceptors sense carbon dioxide
A memory aid for the peripheral and central chemoreceptors.
Bicarbonate leaves the red cell in exchange for chloride entering
A memory aid for the Hamburger phenomenon in red cells.
Chylomicrons carry dietary fat, VLDL endogenous fat, LDL delivers cholesterol, HDL returns it
A memory aid for the lipoprotein classes and their roles.
Remaining nephrons hyperfilter, which compensates but accelerates decline
A memory aid for how surviving nephrons compensate as kidney function falls.
The volume at which dependent small airways begin to close
A memory aid for closing capacity and its relationship to functional residual capacity.
Extrinsic measured by prothrombin time, intrinsic by APTT
A memory aid for the intrinsic, extrinsic and common coagulation pathways.
Immune-mediated villous atrophy in the proximal small bowel
A memory aid for the mechanism of malabsorption in coeliac disease.
Absorbs water and electrolytes, ferments fibre, and stores faeces
A memory aid for what the colon does.
Predictable formulae reveal whether a second disorder is present
A memory aid for the expected compensation in each acid-base disorder.
Classical, alternative and lectin pathways converging on C3
A memory aid for the three complement pathways and their functions.
The lung follows a different path on inflation than on deflation
A memory aid for why the inflation and deflation curves differ.
Purkinje fastest, atrioventricular node slowest
A mnemonic for the relative conduction speeds in the heart.
Arousal requires the brainstem reticular formation and at least one functioning hemisphere
A memory aid for the anatomical basis of consciousness.
Slow transit, outlet obstruction or normal transit with hard stool
A memory aid for the mechanisms of constipation and laxative action.
Suppress ovulation, thicken mucus, or prevent implantation
A memory aid for how each contraceptive method works.
Sympathetic drive and calcium raise it; hypoxia, acidosis and beta blockade lower it
A memory aid for what increases and decreases myocardial contractility.
Medullary vasoconstriction and direct tubular toxicity
A memory aid for the mechanism of contrast-associated kidney injury.
Chronic obstructive pulmonary disease
A chronic respiratory condition characterised by persistent airflow limitation.
Loss of elastic recoil, airway collapse, gas trapping and impaired gas exchange
A memory aid for the physiological changes in chronic obstructive pulmonary disease.
Local metabolic factors dominate, especially adenosine and hypoxia
A memory aid for what controls coronary blood flow.
Dilating already maximally dilated vessels diverts flow away from ischaemic territory
A memory aid for the mechanism of coronary steal.
Body parts are represented in proportion to innervation density, not size
A memory aid for the somatotopic organisation of the cortex.
Raises glucose, breaks down protein and fat, suppresses immunity, and maintains vascular tone
A mnemonic for the metabolic and other actions of cortisol.
Hypotension, hyponatraemia, hyperkalaemia and hypoglycaemia
A memory aid for the features of adrenal insufficiency.
Inspiration, glottic closure, compression, then explosive expiration
A memory aid for the stages and pathway of the cough reflex.
Hairpin capillaries preserve the medullary gradient while still supplying blood
A memory aid for the role of the vasa recta.
The ascending limb pumps out salt, the descending limb loses water, and the gradient multiplies
A memory aid for how the loop of Henle creates the medullary gradient.
Some Say Marry Money But My Brother Says Big Brains Matter More
A mnemonic for the twelve cranial nerves and whether each is sensory or motor.
Each reflex pairs a sensory nerve with a motor nerve
A memory aid for the afferent and efferent limbs of the main cranial nerve reflexes.
Creatinine rises only after substantial loss of filtration, and depends on muscle mass
A memory aid for the limitations of serum creatinine.
Hypertension, bradycardia and irregular respiration
A mnemonic for the triad of raised intracranial pressure.
ACTH dependent or independent, with exogenous steroids the commonest of all
A memory aid for classifying the causes of cortisol excess.
Arteriovenous anastomoses under sympathetic control dominate skin flow
A memory aid for how skin blood flow is controlled.
Inducers speed metabolism and reduce effect; inhibitors slow it and increase effect
A mnemonic for the common enzyme inducers and inhibitors.
Interleukin-1, interleukin-6 and tumour necrosis factor drive the acute phase response
A memory aid for the main inflammatory cytokines.
Physiological dead space equals anatomical plus alveolar dead space
A memory aid for anatomical, alveolar and physiological dead space.
Rectal distension triggers internal sphincter relaxation, with voluntary external sphincter control
A memory aid for the mechanism of defecation.
Microscopic damage from eccentric contraction, not lactate
A memory aid for the mechanism of post-exercise muscle soreness.
Afferent constriction lowers GFR; efferent constriction raises it
A memory aid for how the afferent and efferent arterioles control filtration.
Central lacks the hormone; nephrogenic cannot respond to it
A memory aid for distinguishing central from nephrogenic diabetes insipidus.
Type 1 is absolute insulin deficiency; type 2 is resistance with relative deficiency
A memory aid for distinguishing the types of diabetes.
Insulin deficiency with counter-regulatory excess causes hyperglycaemia and ketogenesis
A memory aid for the mechanism of diabetic ketoacidosis.
Diffusion for small solutes, convection for larger ones, ultrafiltration for water
A memory aid for the transport principles used in dialysis.
Measured with carbon monoxide, reflecting surface area, membrane thickness and haemoglobin
A memory aid for the transfer factor and what alters it.
Widespread activation of coagulation consumes factors and platelets, causing both thrombosis and bleeding
A memory aid for the mechanism and results in DIC.
Bradycardia, peripheral vasoconstriction and splenic contraction
A memory aid for the cardiovascular response to facial immersion.
Beyond a certain effort, higher pleural pressure compresses airways and flow cannot increase
A memory aid for why forced expiration is effort independent.
II, III and aVF inferior; V1 to V4 anterior; I, aVL, V5 and V6 lateral
A memory aid for which ECG leads look at which part of the heart.
P atrial depolarisation, QRS ventricular depolarisation, T ventricular repolarisation
A memory aid for what each ECG wave and interval represents.
Hypercalcaemia shortens the QT interval; hypocalcaemia prolongs it
A memory aid for the cardiac effects of calcium disturbance.
Hyperkalaemia gives tall T waves and a wide QRS; hypokalaemia gives flat T waves and U waves
A memory aid for the cardiac effects of hyperkalaemia and hypokalaemia.
Falling barometric pressure lowers inspired oxygen, driving hyperventilation and acclimatisation
A memory aid for the respiratory adaptations to altitude.
Reduced functional residual capacity, blunted drive, and atelectasis
A memory aid for the respiratory changes under general anaesthesia.
Acetazolamide proximal, loop diuretics in the loop, thiazides distal, potassium sparers in the collecting duct
A memory aid for where each diuretic class acts and its electrolyte effects.
Pressure rises by one atmosphere for every 10 metres of seawater
A memory aid for the respiratory effects of increased ambient pressure.
Muscle wasting, bone loss, orthostatic intolerance and thrombosis
A memory aid for the systemic consequences of prolonged bed rest.
Three bipolar limb leads forming a triangle around the heart
A memory aid for the arrangement of the limb leads.
Stroke volume divided by end-diastolic volume, normally over 50 per cent
A memory aid for calculating and interpreting ejection fraction.
Nitric oxide and prostacyclin dilate; endothelin and thromboxane constrict
A memory aid for the vasoactive substances released by endothelium.
Intrinsic enteric plexuses modulated by parasympathetic and sympathetic input
A memory aid for the intrinsic and extrinsic control of the gut.
Km reflects affinity and Vmax reflects capacity
A memory aid for Michaelis-Menten kinetics and enzyme inhibition.
Point and Shoot: parasympathetic for erection, sympathetic for emission
A memory aid for the mechanism of erection and ejaculation.
Produced by renal interstitial cells in response to hypoxia
A memory aid for the production and action of erythropoietin.
Calcium entry triggers calcium release from the sarcoplasmic reticulum
A memory aid for how a cardiac action potential produces contraction.
Emulsification, lipolysis, micelle formation, absorption and chylomicron export
A memory aid for the steps of fat handling in the gut.
Carnitine shuttles long chain fatty acids into mitochondria for beta oxidation
A memory aid for beta oxidation and its requirements.
Insulin dominates the fed state; glucagon and catecholamines dominate fasting
A memory aid for the metabolic shifts between feeding and fasting.
Fertilisation in the ampulla, implantation about 6 to 10 days later
A memory aid for the events from fertilisation to implantation.
The placenta is the organ of gas exchange, with three shunts bypassing liver and lungs
A memory aid for how the fetal circulation delivers oxygen.
Chloride-driven secretion in utero switches to sodium-driven absorption at birth
A memory aid for the clearance of lung fluid at birth.
The first breath drops pulmonary resistance and clamping the cord raises systemic resistance
A memory aid for the circulatory changes at birth.
Cardiac output equals oxygen consumption divided by the arteriovenous oxygen difference
A memory aid for calculating cardiac output from oxygen consumption.
GFR divided by renal plasma flow, normally about 20 per cent
A memory aid for filtration fraction and what changes it.
Drug absorbed from the gut passes through the liver before reaching the systemic circulation
A memory aid for the first pass effect and how it is bypassed.
Scooped expiratory limb in obstruction; flattening indicates large airway obstruction
A memory aid for interpreting the shape of the flow-volume loop.
Crystalloids distribute by tonicity; colloids stay longer in the plasma
A memory aid for the composition and distribution of intravenous fluids.
Below 1 per cent suggests prerenal; above 2 per cent suggests tubular injury
A memory aid for using FENa to distinguish prerenal from intrinsic renal failure.
The more the ventricle fills, the harder it contracts, within limits
A memory aid for the relationship between ventricular filling and stroke volume.
Reactive oxygen species damage lipids, proteins and DNA unless neutralised
A memory aid for oxidative stress and its defences.
The volume of solute-free water excreted or retained per unit time
A memory aid for the concept of free water clearance.
The balance point where inward lung recoil equals outward chest wall recoil
A memory aid for what raises and lowers functional residual capacity.
A WET BED: Acid-base, Water, Electrolytes, Toxins, Blood pressure, Erythropoietin, vitamin D
A mnemonic for the main functions of the kidney.
Un-ionised drug is absorbed, so weak acids favour the stomach and weak bases the intestine
A memory aid for how gut pH affects drug absorption.
Duodenal fat, acid, hypertonicity and protein all slow emptying
A memory aid for the factors controlling gastric emptying.
Mucus and bicarbonate layer, tight junctions, rapid turnover and good blood flow
A memory aid for how the stomach protects itself from its own acid.
Gastrocolic, enterogastric, gastroileal and intestino-intestinal reflexes
A memory aid for the named reflexes coordinating gut activity.
Acute mesenteric ischaemia affects the small bowel; ischaemic colitis affects watershed colon
A memory aid for the types of intestinal ischaemia.
Gastrin, secretin, cholecystokinin and GIP, each with a distinct trigger
A memory aid for the major gut hormones and their actions.
Glomerular filtration rate
A measure of kidney filtration function.
Fenestrated endothelium, basement membrane, and podocyte foot processes
A memory aid for the three layers of the filtration barrier.
The proximal tubule reabsorbs a constant fraction of whatever is filtered
A memory aid for the constant fractional reabsorption in the proximal tubule.
Glucagon first, then adrenaline, then cortisol and growth hormone
A memory aid for the hormonal defence against hypoglycaemia.
Glucose appears in urine once plasma glucose exceeds about 10 mmol/l
A memory aid for the renal threshold for glucose.
Ten steps converting glucose to two pyruvate, with a net gain of two ATP
A memory aid for the key steps and regulation of glycolysis.
Pulsatile secretion controlled by GHRH and somatostatin, acting largely through IGF-1
A memory aid for the control and actions of growth hormone.
Fermentation, vitamin synthesis, colonisation resistance and immune education
A memory aid for what the intestinal microbiota does.
Peyer's patches, M cells, lamina propria lymphocytes and secretory IgA
A memory aid for the immune apparatus of the gut.
Four globin chains each with a haem group; HbA is two alpha and two beta
A memory aid for haemoglobin structure and the main variants.
Raised reticulocytes, bilirubin and LDH with low haptoglobin
A memory aid for the markers of haemolysis.
Vasoconstriction, platelet plug, coagulation cascade, then fibrinolysis
A memory aid for the stages of haemostasis.
Glycated haemoglobin
A blood marker reflecting average blood glucose over roughly the previous two to three months.
Reflects average glucose over the preceding 8 to 12 weeks
A memory aid for what HbA1c measures and when it misleads.
Outer ear collects, middle ear amplifies, cochlea transduces by place coding
A memory aid for how sound is transduced and conducted.
First degree long PR, second degree some dropped beats, third degree complete dissociation
A memory aid for the degrees of atrioventricular block.
Sympathetic activation, renin-angiotensin activation, and ventricular remodelling
A memory aid for the compensatory mechanisms in heart failure and why they fail.
S1 atrioventricular valves close, S2 semilunar valves close, S3 rapid filling, S4 atrial contraction
A memory aid for what produces each of the four heart sounds.
pH depends on the ratio of bicarbonate to carbon dioxide, not their absolute values
A memory aid for the relationship between pH, bicarbonate and carbon dioxide.
Splanchnic vasodilatation causes intense compensatory renal vasoconstriction
A memory aid for the mechanism of renal failure in liver disease.
Inflation inhibits further inspiration; deflation stimulates it
A memory aid for the pulmonary stretch reflexes.
Uneven hypoxic pulmonary vasoconstriction overperfuses some capillaries
A memory aid for the mechanism of high altitude pulmonary oedema.
Anaemia, pregnancy, thyrotoxicosis, sepsis, beriberi, Paget disease and arteriovenous fistula
A mnemonic for the causes of a high output circulation.
Compare the trophic hormone with the target hormone to localise the lesion
A memory aid for interpreting paired hormone measurements.
Heart rate
The number of heart beats per minute.
Primary hyperparathyroidism and malignancy account for 90 per cent
A memory aid for the causes of a raised calcium.
Stabilise the membrane, shift potassium into cells, then remove it from the body
A memory aid for the three-step approach to hyperkalaemia.
Extreme hyperglycaemia and dehydration without significant ketosis
A memory aid for contrasting HHS with diabetic ketoacidosis.
Physiological, pharmacological, pathological and the stalk effect
A memory aid for the causes of a raised prolactin.
ACID: Anaphylactic, Cytotoxic, Immune complex, Delayed
A mnemonic for the four types of hypersensitivity.
Raised cardiac output early, raised systemic vascular resistance later
A memory aid for the mechanisms underlying essential hypertension.
Respiratory alkalosis causes paraesthesiae, tetany and cerebral vasoconstriction
A memory aid for the physiological consequences of acute hyperventilation.
Neuromuscular irritability with tetany, Chvostek and Trousseau signs
A memory aid for the signs of low calcium.
Check osmolality, then volume status, then urine sodium
A memory aid for the stepwise assessment of hyponatraemia.
GnRH, TRH, CRH and GHRH stimulate; dopamine and somatostatin inhibit
A memory aid for the hypothalamic hormones controlling the pituitary.
Pulmonary arterioles constrict in hypoxia, diverting blood to better ventilated alveoli
A memory aid for the pulmonary vascular response to alveolar hypoxia.
Peripheral chemoreceptors respond only below about 8 kPa
A memory aid for the ventilatory response to hypoxia.
Sympathetic overactivity, inflammation and opioids inhibit coordinated motility
A memory aid for the mechanism of postoperative ileus.
GAMED: IgG, IgA, IgM, IgE, IgD
A mnemonic for the five antibody classes and their roles.
GLP-1 and GIP are released by the gut and amplify insulin secretion
A memory aid for why oral glucose provokes more insulin than intravenous.
Crohn is transmural and patchy anywhere; colitis is mucosal and continuous from the rectum
A memory aid for the physiological differences between Crohn disease and ulcerative colitis.
Innate is immediate and non-specific; adaptive is slower, specific and has memory
A memory aid for the two arms of the immune system.
Promotes storage of glucose, fat and protein, and drives potassium into cells
A memory aid for the anabolic actions of insulin.
Rapid, short, intermediate and long acting, matched to basal and prandial needs
A memory aid for the classes of insulin by duration of action.
About 9 litres enters the gut daily and only 100 ml is lost in stool
A memory aid for the daily fluid load handled by the gut.
Absorbed in the duodenum, controlled by hepcidin acting on ferroportin
A memory aid for the control of iron absorption.
Ferritin low in deficiency, normal or high in chronic disease
A memory aid for distinguishing iron deficiency from anaemia of chronic disease.
Perfusion falls, then metabolism, then diastolic and systolic function, then ECG changes, then pain
A memory aid for the sequence of events after coronary occlusion.
Avascular, aneural cartilage nourished by synovial fluid
A memory aid for the properties of articular cartilage and synovial fluid.
Macula densa, juxtaglomerular cells and extraglomerular mesangial cells
A memory aid for the components of the juxtaglomerular apparatus.
Jugular venous pressure
A clinical sign used to estimate right atrial pressure.
a, c and v waves with x and y descents
A memory aid for the waves and descents of the jugular venous pulse.
Made in the liver from acetyl-CoA, used by brain, heart and muscle
A memory aid for ketone production and use.
Phase 1 gives systolic pressure and phase 5 gives diastolic
A memory aid for the five phases of the Korotkoff sounds.
Acetyl-CoA is oxidised, generating NADH, FADH2 and GTP
A memory aid for the yield and role of the citric acid cycle.
Cervical dilatation, delivery of the fetus, then delivery of the placenta
A memory aid for the three stages of labour and their control.
Prolactin makes milk; oxytocin ejects it
A memory aid for the control of milk production and ejection.
Type A from hypoperfusion, type B without hypoxia
A memory aid for the two types of lactic acidosis.
Reynolds number over about 2000 predicts turbulence
A memory aid for the difference between laminar and turbulent flow.
Wall stress equals pressure times radius divided by twice the wall thickness
A memory aid for how chamber size and wall thickness affect wall stress.
Left failure causes pulmonary congestion; right failure causes systemic congestion
A memory aid for distinguishing left from right heart failure.
Force is greatest at optimal length and falls as shortening velocity rises
A memory aid for the two fundamental muscle mechanics relationships.
Synthesis, storage, metabolism, detoxification, excretion and immune function
A mnemonic for the major functions of the liver.
Block voltage-gated sodium channels from the inside of the axon
A memory aid for how local anaesthetics work and why they fail in infection.
Adenosine, carbon dioxide, hydrogen and potassium ions, and hypoxia
A memory aid for the metabolites that increase local blood flow.
A capacity is two or more volumes added together
A memory aid for the four lung capacities and the volumes that make them up.
Change in volume per unit change in pressure, determined by elastic tissue and surface tension
A memory aid for the determinants of lung compliance.
Volume, Air, Tidal, Inspiratory, Residual, Expiratory
A mnemonic for the key lung volumes and capacities measured in spirometry.
Returns interstitial fluid and protein, absorbs fat, and carries immune cells
A memory aid for the roles of the lymphatic system.
A cofactor for ATP-dependent enzymes and a natural calcium antagonist
A memory aid for the roles and disturbances of magnesium.
About 25 to 30 ml/kg/day of water with 1 mmol/kg each of sodium and potassium
A memory aid for daily fluid and electrolyte requirements.
Luminal, mucosal or postmucosal failure
A memory aid for localising the cause of malabsorption.
LH acts on Leydig cells for testosterone; FSH acts on Sertoli cells for spermatogenesis
A memory aid for the control of testicular function.
Uncontrolled calcium release causes sustained contraction and hypermetabolism
A memory aid for the mechanism and treatment of malignant hyperthermia.
Diastolic pressure plus one third of the pulse pressure
A memory aid for calculating mean arterial pressure.
Deuterium for total body water, inulin for extracellular fluid, albumin for plasma
A memory aid for the indicators used to measure each fluid compartment.
Osmotic, secretory, inflammatory and motility related
A mnemonic for the four mechanisms of diarrhoea.
Declarative memory needs the hippocampus; procedural memory does not
A memory aid for the types of memory and their anatomical basis.
Ovarian follicle depletion causes low oestrogen with high FSH and LH
A memory aid for the hormonal changes of the menopause.
Follicular phase, ovulation at the LH surge, then a fixed 14-day luteal phase
A memory aid for the hormonal and ovarian events of the menstrual cycle.
Generation is one thing; maintenance requires impaired bicarbonate excretion
A memory aid for why metabolic alkalosis persists.
Parasympathetic S2 to S4 empties the bladder; sympathetic and somatic control storage
A memory aid for the neural control of bladder emptying.
Cyclical waves of contraction every 90 to 120 minutes between meals
A memory aid for the housekeeping motility of the fasting gut.
Minute ventilation includes dead space; alveolar ventilation does not
A memory aid for the difference between total and effective ventilation.
Brain, blood and cerebrospinal fluid occupy a fixed volume within a rigid skull
A memory aid for the relationship between intracranial contents and pressure.
Recruitment of more units and increased firing rate, following the size principle
A memory aid for how muscle force is graded.
Cilia beat in a watery sol layer, moving an overlying gel layer of mucus upwards
A memory aid for the airway's mucociliary escalator.
MEN1 is three Ps; MEN2A is two Cs and a P; MEN2B adds mucosal neuromas
A mnemonic for the MEN syndromes.
Systolic murmurs come from stenotic outflow or leaking inflow valves, and diastolic murmurs the reverse
A mnemonic for the causes of systolic and diastolic murmurs.
Phosphocreatine for seconds, glycolysis for minutes, oxidative for hours
A memory aid for the three energy systems supplying muscle.
Central and peripheral mechanisms, with metabolite accumulation and substrate depletion
A memory aid for the causes of muscle fatigue.
Spindles sense length and drive the monosynaptic stretch reflex
A memory aid for the stretch reflex and the role of the muscle spindle.
The diaphragm alone at rest, with accessory muscles for forced inspiration and abdominals for forced expiration
A memory aid for which muscles are used in quiet and forced breathing.
Heart rate, contractility and wall stress
A memory aid for the determinants of myocardial oxygen consumption.
Stunning follows restored flow; hibernation persists with reduced flow
A memory aid for distinguishing stunned from hibernating myocardium.
Hypothermia, hypoventilation, hyponatraemia and reduced consciousness
A memory aid for the features and treatment of severe hypothyroidism.
Released by stretched myocardium; they oppose the renin-angiotensin system
A memory aid for the actions of atrial and brain natriuretic peptide.
Progesterone relaxes smooth muscle, slowing emptying and reducing sphincter tone
A memory aid for the gastrointestinal changes of pregnancy.
Glomerulus, Loop (of Henle), Ascending limb, Renal cortex collecting duct, Collecting Duct
A mnemonic for the main functional segments of the nephron in order.
Glomerulus, proximal tubule, loop of Henle, distal tubule, collecting duct
A memory aid for the sequence of nephron segments and what each does.
A alpha fastest, then A beta, A gamma, A delta, B and C slowest
A memory aid for nerve fibre types by diameter and conduction velocity.
Hypotension with bradycardia and warm peripheries after high spinal cord injury
A memory aid for the distinctive features of neurogenic shock.
Acetylcholine acts on nicotinic receptors and is broken down by acetylcholinesterase
A memory aid for transmission at the neuromuscular junction.
Glutamate excites, GABA inhibits, and the monoamines modulate
A memory aid for the main central neurotransmitters and their roles.
Nicotinic at all ganglia, muscarinic and adrenergic at effector organs
A memory aid for autonomic receptor types and their drugs.
Margination, rolling, adhesion, transmigration, chemotaxis, phagocytosis and killing
A memory aid for the steps of neutrophil action.
Nitric oxide donation causes venodilatation, reducing preload and wall stress
A memory aid for how nitrates relieve angina.
Nitrogen splints alveoli open; replacing it with rapidly absorbed oxygen allows collapse
A memory aid for why high inspired oxygen causes collapse.
Filtration, metabolism, immune defence, acid-base balance and a blood reservoir
A memory aid for the metabolic and defensive roles of the lung.
Peripheral nystagmus is unidirectional and fatigable; central nystagmus is not
A memory aid for classifying nystagmus.
Energy stores are defended by hormonal and metabolic adaptation to weight loss
A memory aid for the physiology of weight regulation.
Repeated pharyngeal collapse causes intermittent hypoxia and arousals
A memory aid for the mechanism and consequences of obstructive sleep apnoea.
Obstruction traps gas and raises volumes; restriction reduces all volumes
A memory aid for the physiological differences between obstruction and restriction.
Mean arterial pressure equals cardiac output multiplied by systemic vascular resistance
A memory aid for the relationship between pressure, flow and resistance.
Automatic breathing is brainstem driven; voluntary breathing bypasses it through corticospinal tracts
A memory aid for the distinction between automatic and voluntary breathing.
Mu receptors give analgesia along with the main side effects
A memory aid for the actions mediated by opioid receptors.
Reduce hepatic output, increase secretion, increase sensitivity, or increase excretion
A memory aid for how each class of diabetes drug works.
Glucose-coupled sodium absorption remains intact even in secretory diarrhoea
A memory aid for why oral rehydration solution works.
Osmoreceptors control antidiuretic hormone and thirst
A memory aid for how plasma osmolality is defended.
Measured minus calculated osmolality, raised by unmeasured osmoles
A memory aid for using the osmolar gap in poisoning.
Unreabsorbed solute in the tubule holds water and drags electrolytes with it
A memory aid for the mechanism and causes of osmotic diuresis.
Osteoporosis is too little normal bone; osteomalacia is poorly mineralised bone
A memory aid for distinguishing the two main metabolic bone diseases.
Oocyte number is fixed before birth and declines continuously thereafter
A memory aid for the decline in female fertility with age.
Electrons pass down the chain, pumping protons that drive ATP synthase
A memory aid for the electron transport chain and chemiosmosis.
Oxygen tension falls stepwise from atmospheric to about 1 kPa in the mitochondrion
A memory aid for the fall in oxygen tension from air to mitochondria.
Tension drives diffusion, saturation describes haemoglobin, content determines delivery
A memory aid for distinguishing oxygen tension, saturation and content.
Excess post-exercise oxygen consumption repays stores and restores homeostasis
A memory aid for why oxygen consumption stays high after exercise.
Delivery equals cardiac output multiplied by arterial oxygen content
A memory aid for calculating oxygen delivery to the tissues.
A sigmoid curve with P50 of about 3.5 kPa or 27 mmHg
A memory aid for the shape and key points of the oxyhaemoglobin curve.
Acid, carbon dioxide, temperature and 2,3-DPG all shift it right
A mnemonic for what shifts the oxygen dissociation curve right.
Variable devices depend on the patient's breathing pattern; fixed devices do not
A memory aid for fixed and variable performance oxygen devices.
Pulmonary damage from free radicals, plus central nervous system toxicity at high pressure
A memory aid for the harmful effects of prolonged high inspired oxygen.
Phase 4 funny current, phase 0 calcium influx, phase 3 potassium efflux
A memory aid for the three phases of the sinoatrial node action potential.
Large fibre input inhibits transmission of small fibre pain signals
A memory aid for the gate control theory of pain.
Transduction, transmission, modulation and perception
A memory aid for the transmission of pain from periphery to cortex.
Bicarbonate from duct cells under secretin, enzymes from acinar cells under cholecystokinin
A memory aid for the two components of pancreatic juice.
Acetylcholine, gastrin and histamine all converge on the proton pump
A memory aid for the three stimuli of acid secretion and the final common pathway.
Nitrous oxide is perfusion limited, carbon monoxide is diffusion limited, oxygen is normally perfusion limited
A memory aid for distinguishing perfusion-limited from diffusion-limited gas transfer.
Cheyne-Stokes waxes and wanes; Kussmaul is deep and rapid; Biot's is irregular
A memory aid for the abnormal breathing patterns and their causes.
Contraction above the bolus and relaxation below it
A memory aid for the reflex that propels intestinal contents.
ADME: Absorption, Distribution, Metabolism, Excretion
A mnemonic for the stages of drug handling.
Cephalic, gastric and intestinal phases
A mnemonic for the three phases of gastric acid secretion.
Reabsorbed proximally, and excretion is increased by parathyroid hormone and FGF23
A memory aid for renal phosphate regulation.
Sudden headache, visual loss and ophthalmoplegia with acute hypopituitarism
A memory aid for haemorrhage or infarction of the pituitary.
Gas exchange, nutrition, excretion, endocrine and barrier functions
A memory aid for the roles of the placenta.
Adhesion, activation, aggregation, then providing a surface for coagulation
A memory aid for the steps of platelet activation.
Transudates from altered Starling forces; exudates from increased permeability
A memory aid for the formation and classification of pleural effusions.
Pleural pressure is more negative at the apex than at the base
A memory aid for the vertical gradient in pleural pressure.
Loss of negative pleural pressure allows the lung to collapse and the chest wall to spring out
A memory aid for the physiological consequences of air in the pleural space.
Flow is proportional to the fourth power of the radius
A memory aid for the determinants of flow through a tube.
Insulin resistance drives ovarian androgen production and disrupts ovulation
A memory aid for the mechanism of PCOS.
Low pressure system carrying 75 per cent of hepatic blood flow
A memory aid for the portal venous system and portal hypertension.
It reverses the normal negative intrathoracic pressure, reducing venous return
A memory aid for the physiological consequences of positive pressure ventilation.
Retained solute and impaired tubular function cause a large diuresis after decompression
A memory aid for the diuresis following relief of urinary obstruction.
Oxytocin and antidiuretic hormone, made in the hypothalamus and stored in the posterior lobe
A memory aid for the two posterior pituitary hormones.
Insulin, beta agonists and alkalosis drive potassium into cells
A memory aid for what moves potassium between compartments.
Filtered, largely reabsorbed proximally, then secreted in the distal nephron
A memory aid for how the kidney regulates potassium.
Cardiac output and volume rise, resistance and blood pressure fall
A memory aid for the circulatory adaptations of pregnancy.
hCG early from trophoblast, then progesterone and oestrogen from the placenta
A memory aid for the hormones of pregnancy and their sources.
Venous return, venous tone, blood volume, atrial contraction, heart rate and compliance
A memory aid for the factors setting ventricular preload.
The greatest fall occurs across the arterioles
A memory aid for how pressure falls from aorta to vena cava.
A rise in arterial pressure increases sodium and water excretion
A memory aid for the relationship between blood pressure and sodium excretion.
Filling, isovolumetric contraction, ejection, isovolumetric relaxation, traced anticlockwise
A memory aid for the four sides of the ventricular pressure-volume loop.
Hypertension with hypokalaemia, high aldosterone and suppressed renin
A memory aid for the features and investigation of Conn syndrome.
It makes ventilation more uniform while perfusion remains relatively unchanged
A memory aid for why proning improves oxygenation.
Pepsin in the stomach, pancreatic proteases in the duodenum, brush border peptidases last
A memory aid for the sequence of protein digestion.
Ammonia from deamination is converted to urea in the liver
A memory aid for nitrogen disposal.
Two-thirds of sodium and water, and essentially all glucose, amino acids and bicarbonate
A memory aid for what the proximal tubule reabsorbs.
Two non-specific pumps secrete a wide range of drugs and endogenous compounds
A memory aid for the organic anion and cation secretory systems.
Reactivation of pulsatile GnRH secretion after childhood quiescence
A memory aid for what initiates puberty.
Breast then pubic hair then growth spurt then menarche in girls; testicular enlargement first in boys
A memory aid for the order of pubertal changes.
An indirect measure of left atrial pressure, obtained by occluding a pulmonary artery branch
A memory aid for what the wedge pressure measures.
Low pressure, low resistance, high compliance, and it constricts in hypoxia
A memory aid for how the pulmonary circulation differs from the systemic.
Increased dead space, hypoxaemia from mismatch, and right ventricular strain
A memory aid for the physiological consequences of pulmonary embolism.
Raised hydrostatic pressure or increased permeability floods the interstitium then alveoli
A memory aid for the mechanisms of pulmonary oedema.
Slow rising in aortic stenosis, collapsing in aortic regurgitation
A memory aid for the abnormal arterial pulse waveforms.
Two wavelengths distinguish oxyhaemoglobin from deoxyhaemoglobin in pulsatile blood
A memory aid for how pulse oximetry works and when it misleads.
Stroke volume divided by arterial compliance
A memory aid for the determinants of pulse pressure.
Low potassium, magnesium and calcium, plus many drugs, prolong the QT interval
A memory aid for the causes of QT prolongation.
Reduce brain water, blood volume or cerebrospinal fluid, or increase the space
A memory aid for the physiological measures that lower intracranial pressure.
Two pathways, unidirectional block and slow conduction
A memory aid for the three conditions needed for a re-entrant arrhythmia.
Driven by erythropoietin, requiring iron, B12 and folate
A memory aid for erythropoiesis and its requirements.
Insulin drives phosphate, potassium and magnesium into cells
A memory aid for the electrolyte shifts on refeeding a malnourished patient.
Myogenic response and tubuloglomerular feedback
A memory aid for the two mechanisms keeping renal blood flow constant.
The cortex receives most of the flow; the medulla is relatively hypoxic
A memory aid for the distribution of blood flow within the kidney.
The volume of plasma completely cleared of a substance per unit time
A memory aid for the clearance concept and its use.
Slow but powerful, taking days but capable of large adjustments
A memory aid for the timing and extent of renal compensation.
Autoregulation and hormonal control persist, but neural reflexes are lost
A memory aid for how a transplanted kidney behaves without nerves.
Filtration of free drug, active secretion, and passive reabsorption depending on pH
A memory aid for how the kidney eliminates drugs.
Bicarbonate reclamation proximally, then titratable acid and ammonium distally
A memory aid for how the kidney excretes acid.
Reabsorbed passively, with the amount depending on tubular flow rate
A memory aid for urea reabsorption and recycling.
Suppressed antidiuretic hormone allows maximally dilute urine
A memory aid for how the kidney excretes a water load.
GFR rises by about 50 per cent, so creatinine and urea fall
A memory aid for the renal adaptations of pregnancy.
Low GFR and limited concentrating ability, maturing over the first two years
A memory aid for the immaturity of neonatal renal function.
Renal blood flow falls as blood is diverted to muscle, with sodium and water conservation
A memory aid for renal changes during exercise.
Reduced filtration, increased proximal reabsorption, and hormonal salt and water retention
A memory aid for how the kidney conserves salt and water in hypovolaemia.
Supersaturation, low urine volume, and lack of inhibitors
A memory aid for the physiological factors promoting kidney stones.
Type 1 distal, type 2 proximal, type 4 hypoaldosteronism
A memory aid for the types of renal tubular acidosis.
Renin, angiotensinogen, angiotensin I, ACE, angiotensin II, aldosterone
A memory aid for the steps of the renin-angiotensin-aldosterone cascade.
Anything reducing alveolar ventilation, from brain to alveolus
A memory aid for the causes of carbon dioxide retention.
Hypoxia, central stimulation, lung disease, drugs and anxiety
A memory aid for the causes of hyperventilation.
Medullary dorsal and ventral groups, with pontine pneumotaxic and apneustic centres
A memory aid for the brainstem centres controlling breathing.
Tidal volume and minute ventilation rise, functional residual capacity falls
A memory aid for the respiratory adaptations of pregnancy.
Type 1 is hypoxaemia alone; type 2 adds hypercapnia
A memory aid for distinguishing type 1 from type 2 respiratory failure.
Carbohydrate 1.0, protein 0.8, fat 0.7, mixed diet about 0.8
A memory aid for the respiratory quotient of different fuels.
Baroreflex tachycardia and vasoconstriction, then fluid shift and hormonal retention
A memory aid for the compensatory response to blood loss.
Blood pools in the legs, venous return falls, and the baroreflex compensates
A memory aid for the circulatory adjustments on standing up.
Potassium permeability dominates, giving about minus 70 millivolts
A memory aid for what sets the resting membrane potential.
Myoglobin, potassium, phosphate and creatine kinase are released into the circulation
A memory aid for the consequences of muscle breakdown.
Respiratory rate
The number of breaths per minute.
Hypotonic fluid with amylase, mucins, lysozyme and bicarbonate
A memory aid for what saliva contains and does.
Progressive loss of muscle mass, strength and function with age
A memory aid for age-related muscle loss.
Systolic blood pressure
The arterial pressure during ventricular contraction.
Excessive synchronous neuronal discharge from an imbalance of excitation and inhibition
A memory aid for the mechanism of seizures.
Volume, concentration, motility and morphology
A memory aid for the reference values of a semen analysis.
Dorsal columns carry fine touch and proprioception; spinothalamic carries pain and temperature
A memory aid for the two main ascending sensory pathways.
SRY drives testis formation; without it the default pathway is female
A memory aid for how the embryo develops as male or female.
Hypovolaemic, cardiogenic, obstructive and distributive
A memory aid for the four categories of shock and their haemodynamic profiles.
Reduced absorptive surface, rapid transit and loss of specialised ileal function
A memory aid for the consequences of extensive small bowel resection.
Measure cortisol before and after synthetic ACTH
A memory aid for the test of adrenal reserve.
Hyponatraemia with concentrated urine in a euvolaemic patient with normal endocrine and renal function
A memory aid for the diagnostic criteria of SIADH.
Never stop insulin, monitor more often, and maintain fluid and carbohydrate intake
A memory aid for managing diabetes during intercurrent illness.
A single amino acid substitution causes polymerisation of deoxygenated haemoglobin
A memory aid for the mechanism and consequences of sickle cell disease.
Heart rate rises on inspiration and falls on expiration through varying vagal tone
A memory aid for the mechanism of respiratory sinus arrhythmia.
Sympathetic tone at rest, metabolic vasodilatation during exercise
A memory aid for the control of blood flow to skeletal muscle.
Type I slow oxidative, type IIa fast oxidative, type IIx fast glycolytic
A memory aid for the differences between slow and fast muscle fibres.
Ventilation falls, carbon dioxide rises slightly and upper airway tone is reduced
A memory aid for the respiratory changes during sleep.
Three non-REM stages and REM sleep, cycling about every 90 minutes
A memory aid for the stages of sleep and their EEG features.
Filaments slide past each other without changing length, powered by ATP
A memory aid for the cross-bridge cycle of muscle contraction.
Impaired clearance, carboxyhaemoglobin, protease imbalance and accelerated decline in FEV1
A memory aid for the physiological effects of cigarette smoking.
Calcium acts through calmodulin and myosin light chain kinase, not troponin
A memory aid for how smooth muscle differs from skeletal muscle.
Proximal 65 per cent, loop 25 per cent, distal 5 per cent, collecting duct 3 per cent
A memory aid for how much sodium each segment reabsorbs.
Spermatogonia to spermatozoa over about 70 days
A memory aid for the stages and timing of sperm production.
Cholecystokinin contracts the gallbladder and relaxes the sphincter
A memory aid for the control of bile delivery to the duodenum.
Dorsal columns behind, corticospinal laterally, spinothalamic anterolaterally
A memory aid for the location and function of the main spinal tracts.
Obstructive lowers the ratio; restrictive lowers both values proportionately
A memory aid for distinguishing obstructive from restrictive spirometry.
Splanchnic flow rises by up to 100 per cent for several hours after eating
A memory aid for the circulatory response to a meal.
A quarter of cardiac output at rest, arranged largely in series through the portal vein
A memory aid for the features of the gastrointestinal circulation.
Filtration, immunity, storage and, in the fetus, haematopoiesis
A mnemonic for the functions of the spleen and the consequences of losing it.
Normal splitting widens on inspiration; wide, fixed and reversed splitting are abnormal
A memory aid for the patterns of S2 splitting and their causes.
Peripheral oxygen saturation
An estimate of haemoglobin oxygen saturation measured by pulse oximetry.
Elevation suggests transmural injury; depression suggests subendocardial ischaemia
A memory aid for the significance of ST segment shift.
Hydrostatic pressure pushes fluid out, oncotic pressure pulls it back
A memory aid for the forces governing fluid movement across capillaries.
Glomerular capillary pressure drives filtration; oncotic and capsular pressures oppose it
A memory aid for the forces determining glomerular filtration.
Dynamic exercise is a volume load; static exercise is a pressure load
A memory aid for the different circulatory loads of isometric and isotonic exercise.
Steroids act on intracellular receptors and alter gene transcription
A memory aid for how steroid hormones differ from peptide hormones.
pH is determined by the strong ion difference, weak acids and carbon dioxide
A memory aid for the strong ion approach to acid-base balance.
Catabolic hormones rise, insulin falls, and salt and water are retained
A memory aid for the hormonal response to injury or surgery.
Preload, Afterload, Contractility
A mnemonic for the three determinants of stroke volume.
Surfactant deficiency causes high surface tension, alveolar collapse and stiff lungs
A memory aid for the physiology of neonatal respiratory distress syndrome.
Reduces surface tension, increases compliance, stabilises alveoli and keeps them dry
A memory aid for the roles of pulmonary surfactant.
Oral voluntary, pharyngeal reflex, oesophageal peristalsis
A memory aid for the three phases of swallowing.
Depolarisation, calcium entry, vesicle fusion, receptor binding, then termination
A memory aid for the sequence of chemical synaptic transmission.
Reflex, orthostatic and cardiac causes, all reducing cerebral perfusion
A memory aid for the cardiovascular causes of transient loss of consciousness.
About one-third systole and two-thirds diastole at rest
A memory aid for how the cardiac cycle divides between systole and diastole.
CD4 helper cells coordinate; CD8 cytotoxic cells kill
A memory aid for the T lymphocyte subsets and their functions.
Five basic tastes carried by three cranial nerves, and smell by the olfactory nerve
A memory aid for the chemical senses and their innervation.
The hypothalamus compares core temperature with a set point and drives heat loss or gain
A memory aid for the control of body temperature.
Dense type I collagen with poor blood supply and slow healing
A memory aid for the properties and healing of tendon.
Evaporation is the main route of heat loss, and it fails in high humidity
A memory aid for heat production and loss during exercise.
Reduced production, increased destruction, sequestration or dilution
A memory aid for classifying a low platelet count.
Factor V Leiden is commonest inherited; antiphospholipid syndrome commonest acquired
A memory aid for inherited and acquired thrombophilia.
TSH is the most sensitive marker, moving before free T4 changes
A memory aid for interpreting thyroid function tests.
Increases basal metabolic rate and potentiates catecholamine effects
A memory aid for the systemic effects of thyroid hormone.
Iodide trapping, oxidation, organification, coupling, storage and release
A memory aid for the steps of thyroid hormone production.
Over 99 per cent is protein bound, so only the free fraction is active
A memory aid for thyroid hormone binding proteins and their effect on tests.
Block synthesis, block release, block conversion, block effects, and support
A memory aid for the management of thyrotoxic crisis.
Time constant equals resistance multiplied by compliance
A memory aid for how compliance and resistance determine filling and emptying.
Zinc, copper, iodine, selenium and chromium, each with a characteristic syndrome
A memory aid for the essential trace elements and their deficiency states.
Endurance training improves oxygen delivery and use; resistance training increases muscle size and neural drive
A memory aid for the adaptations to endurance and resistance training.
Acute haemolytic, febrile, allergic, TACO and TRALI
A memory aid for the types of transfusion reaction.
Alveolar pressure minus pleural pressure
A memory aid for the pressure that actually inflates the lung.
Hypoxic, anaemic, stagnant and histotoxic
A mnemonic for the four classes of tissue hypoxia.
Upper gives spasticity and brisk reflexes; lower gives wasting and absent reflexes
A memory aid for distinguishing upper from lower motor neurone signs.
Accumulated toxins affect nearly every system once GFR falls very low
A memory aid for the multisystem effects of uraemia.
Filtered, almost completely reabsorbed, then secreted, with net excretion about 10 per cent
A memory aid for renal handling of urate and the causes of hyperuricaemia.
From 50 to 1200 mOsm per kilogram, needing an intact loop, gradient and hormone
A memory aid for the range of urine osmolality and what is required for each extreme.
Live attenuated give strong lasting immunity; inactivated are safer but need boosters
A memory aid for the types of vaccine and their properties.
Intrinsic sinoatrial rate is about 100; resting vagal tone brings it down to about 70
A memory aid for the dominance of parasympathetic tone in the resting heart.
Pressure rise, reduced venous return, release, then overshoot
A memory aid for the four phases of the Valsalva manoeuvre.
Stenosis creates a pressure load; regurgitation creates a volume load
A memory aid for the loading conditions produced by each valve lesion.
Vasopressors squeeze the vessels; inotropes squeeze the heart
A memory aid for classifying vasoactive drugs by their receptor actions.
Sodium blockers, Beta blockers, Potassium blockers, Calcium blockers
A mnemonic for the classes of antiarrhythmic drug.
Mean systemic filling pressure, right atrial pressure and venous resistance
A memory aid for the factors driving blood back to the heart.
Dependent regions receive more ventilation and more perfusion in the spontaneously breathing patient
A memory aid for how posture changes the distribution of ventilation and perfusion.
Ventilation rises linearly with work until the anaerobic threshold, then disproportionately
A memory aid for the ventilatory response to exercise.
A ratio of zero is shunt; a ratio of infinity is dead space
A memory aid for the V/Q ratio and its extremes.
Carbon dioxide is the dominant drive, sensed centrally through cerebrospinal fluid pH
A memory aid for the main stimulus to breathing.
Rapid filling, diastasis and atrial systole
A memory aid for the three phases of diastolic filling.
Semicircular canals sense rotation; otolith organs sense linear acceleration and gravity
A memory aid for how balance is sensed.
Lesion site determines the pattern, from monocular loss to homonymous hemianopia
A memory aid for localising lesions in the visual pathway.
Bound by R protein, transferred to intrinsic factor, absorbed in the terminal ileum
A memory aid for the steps of vitamin B12 absorption.
25-hydroxylation in the liver, 1-alpha hydroxylation in the kidney
A memory aid for the two hydroxylation steps activating vitamin D.
Fat-soluble ADEK and the water-soluble B vitamins and C
A memory aid for the classic vitamin deficiency syndromes.
Cardiac output is the main limiting factor, not the lungs
A memory aid for maximal oxygen uptake and what limits it.
Four inputs converge on the vomiting centre in the medulla
A memory aid for the pathways triggering vomiting.
Cortisol, aldosterone and antidiuretic hormone disorders each disturb sodium differently
A memory aid for the endocrine causes of sodium abnormalities.
Deprive water, measure urine osmolality, then give desmopressin
A memory aid for interpreting the water deprivation test.
Alveolar pressure dominates at the apex, arterial pressure at the base
A memory aid for the three zones of pulmonary blood flow.
Neutrophils, Lymphocytes, Monocytes, Eosinophils, Basophils
A mnemonic for the white cell types in order of abundance.
Elastic arteries store energy in systole and release it in diastole
A memory aid for the role of aortic elasticity.
Elastic work plus resistive work, minimised at an optimal respiratory rate
A memory aid for the components of the work of breathing.