Human Pathophysiology and Pharmacology 2 - Comprehensive Exam Prep

Comprehensive vocabulary flashcards covering the pathophysiology, clinical presentations, diagnostic investigations, and pharmacological management of cardiovascular, respiratory, endocrine, gastrointestinal, renal, and fluid-electrolyte/acid-base disorders from Human Pathophysiology and Pharmacology 2.

Atherosclerosis

The progressive build-up of fatty plaques (atheroma) inside artery walls, causing them to narrow, harden, and lose elasticity, thereby impairing arterial blood flow.

Intermittent Claudication

Severe, cramping skeletal muscle pain in the legs occurring during exercise or walking due to tissue ischaemia, characteristically relieved by rest; a cardinal feature of peripheral arterial disease (PAD).

Virchow's Triad

The three primary pathophysiological factors contributing to venous thrombosis: venous stasis (e.g. immobility), endothelial or vessel wall injury (e.g. trauma or inflammation), and hypercoagulability (e.g. surgery, malignancy, or dehydration).

Systemic Vascular Resistance (SVR)

The resistance to blood flow created by the systemic arterial vasculature that the left ventricle must pump against, primarily determined by arteriolar diameter and vascular tone.

Malignant (Resistant) Hypertension

Severe high blood pressure that cannot be controlled despite the use of $> 3$ antihypertensive medications, characterized by very high diastolic blood pressure and high risk of rapid target organ damage.

Cardiac Troponin (Troponin I)

The most sensitive and specific biomarker of myocardial cell necrosis; levels rise $4\text{--}6\,\text{hours}$ following myocardial infarction, peak at approximately $12\,\text{hours}$, and remain elevated for $3\text{--}10\,\text{days}$.

Stable Angina

Predictable, transient substernal chest discomfort caused by myocardial ischaemia when myocardial oxygen demand exceeds supply, typically triggered by exertion or emotional stress, lasting $5\text{--}15\,\text{minutes}$, and relieved by rest or sublingual nitroglycerin.

Prinzmetal (Variant) Angina

Chest discomfort resulting from coronary artery vasospasm that occurs unpredictably at rest or during sleep, often shows transient ST-segment elevation on ECG, and is relieved by nitroglycerin.

STEMI (ST-Elevation Myocardial Infarction)

An acute heart attack characterized by complete coronary artery occlusion leading to transmural ischaemia, persistent ST-segment elevation on a 12-lead ECG, and requiring emergency reperfusion therapy via percutaneous coronary intervention (PCI) or thrombolysis.

Ventricular Fibrillation (VF)

A chaotic, disorganized ventricular rhythm with no discernible complexes and no effective ventricular contraction or cardiac output, representing a shockable cardiac arrest state requiring immediate unsynchronized defibrillation and CPR.

Preload

The volume of blood filling the ventricles at the end of diastole (end-diastolic pressure); increased by hypervolaemia, regurgitant heart valves, and congestive heart failure.

Afterload

The resistance or pressure against which the ventricle must contract to eject blood into the circulation; increased by systemic hypertension and arteriolar vasoconstriction.

Pernicious Anaemia

A macrocytic, megaloblastic anaemia caused by autoimmune destruction of gastric parietal cells, resulting in intrinsic factor deficiency and impaired absorption of dietary vitamin $B_{12}$ in the terminal ileum.

Polycythaemia Vera

A primary absolute myeloproliferative neoplasm characterized by autonomous overproduction of red blood cells (erythrocytes) accompanied by low serum erythropoietin (EPO), high blood viscosity, and aquagenic pruritus.

Heparin

A parenteral anticoagulant that binds to and accelerates the activity of antithrombin III, thereby inactivating thrombin and factor $Xa$; therapeutic effect is monitored via activated partial thromboplastin time (aPTT) and reversed with protamine sulfate.

Warfarin

An oral anticoagulant that competitively inhibits vitamin K epoxide reductase, suppressing the hepatic synthesis of clotting factors $II$, $VII$, $IX$, and $X$; monitored using the International Normalized Ratio (INR) and reversed with vitamin K.

Cheyne-Stokes Respiration

An abnormal breathing pattern marked by cycles of gradually increasing respiratory depth and rate followed by a gradual decrease, culminating in a period of apnoea.

Kussmaul Breathing

A pattern of deep, rapid, regular respirations that acts as a respiratory compensatory mechanism to eliminate carbon dioxide in states of severe metabolic acidosis, classically seen in diabetic ketoacidosis (DKA).

Stridor

A harsh, high-pitched respiratory sound heard predominantly on inspiration, indicating turbulent airflow through a narrowed or obstructed upper airway (e.g. croup, acute epiglottitis).

Digital Clubbing

Bulbous soft-tissue enlargement of the terminal phalanges with loss of the normal nail bed angle ($> 180^\circ$), associated with chronic hypoxaemic disorders, bronchiectasis, cystic fibrosis, and lung malignancy.

Forced Expiratory Volume in 1 Second ($\text{FEV}_1$)

The volume of air exhaled forcefully during the first second of a forced vital capacity maneuver; reduced in both obstructive and restrictive disorders, but selectively reduced relative to FVC ($\text{FEV}_1/\text{FVC} < 0.70$ or $< 80\%$) in obstructive disease.

Type 1 Respiratory Failure (Hypoxaemic)

Respiratory failure defined by inadequate blood oxygenation with a reduced arterial oxygen tension ($\text{PaO}_2 < 60\,\text{mmHg}$ or low) and a normal or decreased arterial carbon dioxide tension ($\text{PaCO}_2$), commonly caused by ventilation-perfusion ($V/Q$) mismatch or diffusion impairment.

Type 2 Respiratory Failure (Hypercapnic)

Ventilatory failure characterized by both severe arterial hypoxaemia and hypercapnia ($\text{PaCO}_2 > 45\,\text{mmHg}$), arising from alveolar hypoventilation due to central respiratory depression, respiratory muscle exhaustion, or severe chronic airway obstruction.

Epiglottitis

A rapid-onset, life-threatening bacterial infection of the supraglottic structures (most commonly Haemophilus influenzae type b) causing severe airway swelling, drooling, dysphagia, stridor, and a characteristic forward-leaning tripod position.

Bronchiolitis

An acute viral lower respiratory tract infection of the small airways (bronchioles) occurring primarily in infants under $2\,\text{years}$ of age, predominantly caused by Respiratory Syncytial Virus (RSV) and presenting with wheeze, tachypnoea, and chest retractions.

Chronic Bronchitis

A form of chronic obstructive pulmonary disease (COPD) clinically defined by a persistent, mucus-producing cough for at least $3\,\text{months}$ in $2$ consecutive years, marked by goblet cell hyperplasia, impaired ciliary clearance, and chronic airflow limitation ("blue bloaters").

Emphysema

A chronic, progressive obstructive lung condition characterized by irreversible destruction of alveolar septal walls and enlargement of distal air spaces, resulting in loss of lung elastic recoil, expiratory airflow limitation, and air trapping ("pink puffers").

Neonatal Respiratory Distress Syndrome (NRDS)

A restrictive parenchymal lung disease in premature infants ($< 37\,\text{weeks}$ gestation) caused by a quantitative deficiency in pulmonary surfactant from immature type II alveolar cells, leading to increased alveolar surface tension and diffuse atelectasis.

Tension Pneumothorax

A life-threatening medical emergency where air accumulates in the pleural cavity through a one-way valve mechanism, progressively increasing intrathoracic pressure, collapsing the ipsilateral lung, shifting mediastinal structures to the contralateral side, and obstructing venous return.

Altered Tissue Responsiveness

A category of endocrine dysfunction in which circulating hormone levels are normal or elevated, but target tissues fail to respond appropriately due to reduced receptor numbers, decreased receptor sensitivity, or defective post-receptor intracellular signaling (e.g. insulin resistance in Type 2 Diabetes).

Dynamic Function Tests

Diagnostic endocrine protocols that evaluate glandular reserve and feedback mechanisms by administering a stimulatory hormone when hyposecretion is suspected (e.g. ACTH stimulation test) or an inhibitory agent when hypersecretion is suspected (e.g. dexamethasone suppression test).

Acromegaly

A hypersecretory endocrine condition resulting from excessive growth hormone (GH) and IGF-1 secretion occurring after the fusion of epiphyseal growth plates in adulthood, characterized by enlargement of the hands, feet, jaw (prognathism), and coarse facial features.

Diabetes Insipidus (DI)

A fluid regulation disorder caused by deficient antidiuretic hormone (ADH) secretion (neurogenic) or impaired renal tubular responsiveness to ADH (nephrogenic), manifesting as profound polyuria with dilute urine and excessive thirst (polydipsia).

Graves' Disease

An autoimmune hyperthyroid condition caused by autoantibodies that bind to and activate TSH receptors on thyroid follicular cells, causing toxic diffuse goitre, exophthalmos, hyperhidrosis, and increased basal metabolic rate.

Addisonian Crisis

An acute, life-threatening exacerbation of primary adrenal insufficiency triggered by physiological stress, characterized by profound hypotension, vascular collapse, severe dehydration, hyponatraemia, hyperkalaemia, and shock; managed urgently with IV hydrocortisone and $0.9\%$ saline.

Cushing's Syndrome

A clinical constellation resulting from chronic hypercortisolism, characterized by central abdominal obesity, "moon face", dorsocervical fat pad ("buffalo hump"), purple abdominal striae, muscle wasting of the extremities, and impaired glucose tolerance.

Diabetic Ketoacidosis (DKA)

An acute metabolic emergency arising from severe or absolute insulin deficiency (chiefly in Type 1 Diabetes), resulting in profound hyperglycaemia, excessive lipolysis, hepatic ketogenesis, high anion-gap metabolic acidosis, Kussmaul respirations, and acetone breath.

Hyperosmolar Hyperglycaemic State (HHS)

A life-threatening acute complication seen predominantly in older individuals with Type 2 Diabetes, characterized by extreme hyperglycaemia, severe hyperosmolarity, and profound dehydration in the absence of significant ketoacidosis.

Ulcerative Colitis (UC)

A chronic inflammatory bowel disease restricted to the mucosa and submucosa of the colon and rectum, presenting in an uninterrupted continuous retrograde distribution from the rectum, manifesting with bloody diarrhoea and tenesmus.

Crohn's Disease

A chronic relapsing inflammatory bowel disorder that can affect any segment of the gastrointestinal tract from mouth to anus with transmural inflammation and discontinuous "skip lesions", frequently resulting in fistulas, strictures, and nutrient malabsorption.

Coeliac Disease

An autoimmune small intestinal enteropathy triggered by the ingestion of dietary gluten, producing a T-cell-mediated immune response characterized by enterocyte damage, villous atrophy, crypt hyperplasia, and positive anti-tissue transglutaminase (anti-tTG) antibodies.

Alanine Aminotransferase (ALT)

A liver-specific intracellular enzyme that leaks into the circulation following hepatocellular membrane damage or necrosis; elevated levels ($> 40\,\text{U/L}$) serve as a sensitive indicator of acute hepatocellular injury.

Portal Hypertension

Pathological elevation of blood pressure within the hepatic portal venous system resulting from increased intrahepatic vascular resistance in cirrhosis, leading to splenomegaly, ascites, and dilated collateral vessels such as oesophageal varices.

Acute Pancreatitis

Sudden pancreatic inflammation triggered by premature intracellular activation of digestive proenzymes (such as trypsinogen to trypsin), leading to parenchymal autodigestion, severe epigastric pain radiating to the back, and marked elevations in serum amylase and lipase.

Loop Diuretics

A class of potent diuretic agents (e.g. furosemide, bumetanide) that act on the thick ascending limb of the loop of Henle by blocking the $\text{Na}^+/\text{K}^+/2\text{Cl}^-$ cotransporter, producing marked excretion of sodium, chloride, and water.

Staghorn Calculus

A large renal calculus that branches to occupy the renal pelvis and multiple calyces, typically composed of struvite (magnesium ammonium phosphate) formed in the presence of alkaline urine produced by urease-producing bacterial pathogens (e.g. Proteus).

Acute Kidney Injury (AKI)

A rapid, abrupt decline in glomerular filtration rate occurring over hours to days, leading to azotaemia (retention of urea and creatinine), fluid volume disturbances, and electrolyte imbalances; classified into prerenal, intrarenal, and postrenal aetiologies.

Chronic Kidney Disease (CKD)

Progressive, irreversible structural kidney damage or loss of functioning nephrons persisting for $> 3\,\text{months}$, categorized by estimated glomerular filtration rate (eGFR) from Stage 1 ($\ge 90\,\text{mL/min}/1.73\,\text{m}^2$) down to Stage 5 ($< 15\,\text{mL/min}/1.73\,\text{m}^2$, end-stage kidney disease).

Effective Filtration Pressure (EFP)

The net physical pressure governing fluid movement across capillary endothelial walls, determined by Starling forces according to the equation: $\text{EFP} = (\text{CHP} + \text{IFOP}) - (\text{COP} + \text{IFHP})$, yielding net filtration at the arterial end and net reabsorption at the venous end.

Third-Spacing

The pathological shift and sequestration of fluid from the intravascular compartment into non-functional interstitial spaces or body compartments (e.g. peritoneal cavity in ascites, burn tissues), creating hypovolaemia despite normal total body water.

Hypovolaemic Shock

A critical state of circulatory failure and cellular hypoperfusion resulting from severe loss of intravascular fluid volume (blood or plasma), presenting with hypotension, tachycardia, oliguria, tachypnoea, cool clammy skin, and lactic acidosis.

Hyponatraemia

A serum sodium concentration $< 135\,\text{mmol/L}$, resulting in reduced extracellular fluid osmolality that drives water movement into cells, potentially causing cellular swelling and life-threatening cerebral oedema.

Hyperkalaemia

A serum potassium level $> 5.0\,\text{mmol/L}$, which partially depolarizes the resting membrane potential of excitable cells, producing muscle weakness, paraesthesias, and characteristic ECG alterations (tall, tented T waves, widened QRS), with high risk of lethal cardiac arrest.

Chloride Shift

The reciprocal exchange of chloride ($\text{Cl}^-$) and bicarbonate ($\text{HCO}_3^-$) ions across red blood cell membranes to maintain electrical neutrality and assist blood buffer transport during gas exchange and acid-base shifts.

Metabolic Acidosis

An acid-base disturbance characterized by a serum pH $< 7.35$ and a primary decrease in plasma bicarbonate concentration ($\text{HCO}_3^- < 22\,\text{mmol/L}$), caused by accumulation of metabolic acids (e.g. lactic acid, ketoacids), bicarbonate loss (e.g. diarrhoea), or renal failure.

Respiratory Acidosis

An acid-base derangement characterized by a serum pH $< 7.35$ accompanied by primary carbon dioxide retention ($\text{PaCO}_2 > 45\,\text{mmHg}$) resulting from hypoventilation, airway obstruction, or central nervous system respiratory depression.