Comprehensive Human Pathophysiology and Pharmacology Review (Weeks 1 to 9)

Comprehensive vocabulary flashcards reviewing fundamental concepts in pathophysiology and pharmacology across cellular adaptation, pain pathways, immune disorders, cardiovascular conditions, respiratory diseases, endocrine dysfunction, and diabetes mellitus.

Atrophy

A cellular adaptation where cells decrease in size, such as skeletal muscle shrinking when a limb is immobilised.

Hypertrophy

A cellular adaptation where individual cells increase in size, such as cardiac muscle enlargement resulting from long-term hypertension.

Hyperplasia

An increase in the total number of cells in an organ or tissue, such as the proliferation of endometrial cells in response to estrogenic stimulation.

Metaplasia

The reversible transformation of one mature, differentiated cell type into another mature cell type, such as the substitution of ciliated columnar respiratory epithelium with stratified squamous epithelium in response to cigarette smoke.

Dysplasia

Disordered cellular growth characterised by cells of abnormal size, shape, and architectural organisation, frequently observed in precancerous cervical screening specimens.

Apoptosis

A controlled, energy-dependent pathway of programmed cell death in which cellular contents are packaged into membrane-bound apoptotic bodies without membrane leakage, provoking little or no inflammatory reaction.

Coagulative Necrosis

A morphologic type of uncontrolled cell death in which the underlying structural architecture of the dead tissue is preserved for several days, classically occurring after ischaemic injury in solid organs such as the heart.

Cyclooxygenase (COX)

An enzymatic target inhibited by non-steroidal anti-inflammatory drugs (NSAIDs) to reduce prostaglandin production; COX-1 regulates gastric mucosal protection and platelet aggregation, while COX-2 mediates inflammatory prostaglandin synthesis.

Nociception

The physiological four-stage process by which the nervous system detects, encodes, and transmits potentially tissue-damaging mechanical, thermal, or chemical stimuli: transduction, transmission, perception, and modulation.

Transduction (Nociception)

The primary stage of nociception wherein peripheral noxious stimuli are converted into electrical action potentials by specialised high-threshold sensory nerve endings (nociceptors) exposed to inflammatory chemicals.

Neuropathic Pain

Pain arising as a direct consequence of a lesion or disease affecting the somatosensory nervous system, often presenting with burning, lancinating, shooting, electric, or tingling sensations.

Allodynia

Pain provoked by a mechanical or thermal stimulus that does not normally provoke pain, such as light touch or brushing of clothing against intact skin.

Hyperalgesia

An abnormally increased, exaggerated pain response to a stimulus that is ordinarily painful.

N-Acetylcysteine (NAC)

The specific pharmacological antidote for paracetamol toxicity that prevents acute hepatotoxicity by replenishing intracellular hepatic glutathione pools to conjugate the toxic reactive intermediate NAPQI.

Naloxone

A pure, competitive opioid receptor antagonist administered to reverse life-threatening opioid-induced central nervous system and respiratory depression.

Natural Killer (NK) Cells

Cytotoxic innate lymphocytes that recognize abnormal host cells displaying decreased MHC class I molecules or elevated stress signals, releasing perforin and granzymes to induce target cell apoptosis.

Type I Hypersensitivity

An immediate IgE-mediated immune reaction wherein re-exposure to an allergen cross-links pre-formed IgE on the surface of sensitised mast cells and basophils, causing rapid degranulation and release of histamine and leukotrienes.

Acute Haemolytic Transfusion Reaction

A type II cytotoxic hypersensitivity reaction triggered by an ABO-incompatible red blood cell transfusion, in which recipient antibodies bind donor surface antigens, activate the complement cascade, and induce intravascular red cell destruction.

Systemic Lupus Erythematosus (SLE)

A chronic systemic autoimmune disease characterised by a failure of self-tolerance, generation of antinuclear and other autoantibodies, and type III immune-complex tissue deposition causing widespread microvascular inflammation in skin, joints, and kidneys.

Beta-1 ($\beta_1$) Adrenergic Receptor

A G-protein coupled adrenergic receptor found predominantly in the myocardium and juxtaglomerular apparatus; its stimulation by adrenaline or noradrenaline increases heart rate, cardiac contractility, and renin secretion.

Hypertension

A clinical condition characterized by persistent, sustained elevation of systemic blood pressure, commonly diagnosed in Australian office practice at or above $140/90\,\text{mmHg}$, determined by cardiac output multiplied by systemic vascular resistance.

Atherosclerosis

A disease of large and medium muscular and elastic arteries initiated by endothelial dysfunction, low-density lipoprotein (LDL) accumulation and oxidation, foam cell proliferation, and fibrous cap formation, culminating in luminal narrowing or thrombosis.

Foam Cell

A lipid-laden macrophage or vascular smooth muscle cell in the tunica intima that has ingested oxidised low-density lipoprotein (LDL) particles, representing the hallmark cellular constituent of an atherosclerotic fatty streak.

Myocardial Ischaemia

An imbalance between myocardial oxygen demand and supply through the coronary circulation, producing reversible cellular hypoxia and transient chest tightness (angina) without immediate myocardial cell death.

Acute Coronary Syndrome (ACS)

An operational spectrum of clinical presentations resulting from acute disruption of coronary atherosclerotic plaque and thrombus formation, categorised into unstable angina, non-ST-elevation myocardial infarction (NSTEMI), and ST-elevation myocardial infarction (STEMI).

Cardiac Troponin

A regulatory contractile protein complex specific to myocardial tissue that is released into the systemic circulation following cardiomyocyte necrosis, serving as the gold-standard diagnostic biomarker for myocardial infarction.

Heart Failure with Reduced Ejection Fraction (HFrEF)

A clinical syndrome characterised by impaired left ventricular contractility and an ejection fraction below normal, leading to reduced forward cardiac output and compensatory activation of the sympathetic and renin-angiotensin-aldosterone systems.

Ventricular Fibrillation (VF)

A pulseless, highly disorganised cardiac dysrhythmia originating in the ventricles that results in absence of coordinated mechanical ventricular systole, causing immediate cardiac arrest that requires early cardiopulmonary resuscitation and electrical defibrillation.

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

The volume of air an individual can forcefully expel from maximally inflated lungs during the first second of a spirometric forced vital capacity manoeuvre.

Acute Respiratory Distress Syndrome (ARDS)

A severe form of acute non-cardiogenic pulmonary oedema and respiratory failure resulting from widespread inflammatory injury to the alveolar-capillary barrier, leading to diffuse proteinaceous alveolar flooding, surfactant loss, and non-compliant lungs.

Aspiration Pneumonitis

An acute non-infectious chemical burn of the tracheobronchial tree and pulmonary parenchyma triggered by the inhalation of acidic gastric contents, resulting in rapid alveolar-capillary leak and hypoxaemia.

Chronic Obstructive Pulmonary Disease (COPD)

A chronic, progressive pulmonary disorder characterised by persistent, post-bronchodilator airflow limitation defined spirometrically by an $\text{FEV}_1/\text{FVC}$ ratio of $< 0.70$, commonly encompassing emphysema and chronic bronchitis.

Emphysema

A structural phenotype of COPD characterised by irreversible destruction of alveolar septal walls and terminal bronchioles, causing loss of elastic recoil, premature airway collapse upon exhalation, and air trapping.

Chronic Bronchitis

A clinical airway condition defined by persistent productive cough for at least $3\,\text{months}$ per year in each of $2$ consecutive years, caused by goblet cell hyperplasia, mucus hypersecretion, and chronic bronchial inflammation.

Cor Pulmonale

Right ventricular enlargement (hypertrophy or dilation) and potential failure occurring secondary to pulmonary arterial hypertension brought on by chronic hypoxic lung diseases or vascular disorders.

Tension Pneumothorax

A medical emergency in which air enters the pleural cavity through a one-way ball-valve lesion, progressively elevating intrapleural pressure, collapsing the ipsilateral lung, shifting mediastinal structures, and compressing the vena cava to cause obstructive shock.

Bronchiectasis

A chronic pulmonary disease characterised by permanent, abnormal dilation and wall destruction of the bronchi caused by repeated bacterial infection and defective clearance of pooling purulent secretions.

Syndrome of Inappropriate Antidiuretic Hormone (SIADH)

An endocrine disorder resulting from unsuppressed, autonomous secretion of antidiuretic hormone (vasopressin), leading to excessive renal free-water reabsorption, inappropriate urine concentration, and hypotonic dilutional hyponatraemia.

Diabetes Insipidus (DI)

A metabolic state caused by absolute deficiency of antidiuretic hormone release (central) or renal tubular insensitivity to circulating vasopressin (nephrogenic), resulting in polyuria of large volumes of dilute urine, polydipsia, and hypernatraemic dehydration.

Cushing Syndrome

A clinical state induced by chronic excess circulating glucocorticoids (cortisol), manifesting with central adiposity, round moon face, proximal muscle weakness, purple cutaneous striae, and secondary hyperglycaemia.

Addison Disease

Primary chronic adrenal insufficiency caused by destruction of the adrenal cortex, producing combined deficiencies of cortisol and aldosterone, characterized by weakness, hypotension, hyponatraemia, hyperkalaemia, and cutaneous hyperpigmentation.

Graves Disease

An autoimmune form of primary hyperthyroidism caused by circulating thyroid-stimulating immunoglobulins (TSI) directed against thyrotropin (TSH) receptors, causing autonomous hormone synthesis, diffuse goitre, and thyroid eye disease.

Parathyroid Hormone (PTH)

A peptide hormone produced by parathyroid chief cells that increases plasma calcium concentration by stimulating osteoclast bone resorption, enhancing distal renal tubular calcium reabsorption, and promoting renal synthesis of active calcitriol.

Type 1 Diabetes Mellitus

A chronic endocrine condition characterized by T-cell-mediated autoimmune destruction of insulin-producing pancreatic beta cells within the islets of Langerhans, resulting in absolute insulin deficiency.

Type 2 Diabetes Mellitus

A progressive metabolic disorder characterised by peripheral tissue insulin resistance combined with a gradual secretory decline in pancreatic beta-cell compensation, culminating in sustained chronic hyperglycaemia.

Diabetic Ketoacidosis (DKA)

An acute metabolic complication marked by severe absolute insulin deficiency, marked lipolysis, elevated free fatty acid hepatic conversion into acetoacetate and beta-hydroxybutyrate, metabolic acidosis, and Kussmaul respirations.

Hyperosmolar Hyperglycaemic State (HHS)

A life-threatening acute metabolic crisis seen primarily in Type 2 diabetes characterised by profound hyperglycaemia, marked serum hyperosmolality, and severe dehydration without significant ketoacidosis.

Glycated Haemoglobin ($\text{HbA}_{1\text{c}}$) Diagnostic Threshold

A diagnostic blood test measuring the percentage of haemoglobin bound to glucose over a period of roughly $2\text{ to }3\,\text{months}$, where a laboratory level of $\ge 6.5\%\,(48\,\text{mmol/mol})$ meets the diagnostic criterion for diabetes mellitus.

Metformin

An oral biguanide antidiabetic medication that acts predominantly by suppressing hepatic gluconeogenesis and increasing peripheral insulin sensitivity without stimulating endogenous insulin release or directly causing hypoglycaemia.