MRCS Part A Physiology & Pathology Lecture Notes

Comprehensive vocabulary flashcards covering basic applied surgical anatomy, physiology, and pathology for MRCS Part A preparation.

Anatomical Dead Space

The volume of air contained within the conducting airways of the lungs.

Surfactant

A lipid surface tension-lowering agent produced in the lamellar bodies of type II alveolar epithelial cells; deficiency causes infant respiratory distress syndrome.

Frank-Starling Law

The physiological principle stating that stroke volume is a function of end-diastolic volume; the greater the stretch of the ventricle in diastole, the greater the volume of blood ejected.

Pringle’s Manoeuvre

A surgical technique involving the compression of the free edge of the lesser omentum (containing the hepatic artery and portal vein) to control life-threatening liver bleeding.

Metaplasia

A reversible transformation where one type of terminally differentiated cell is replaced by another fully differentiated cell type (e.g., Barrett’s oesophagus).

Dysplasia

A potentially premalignant condition characterized by increased mitotic activity, high nuclear-cytoplasmic ratio, and decreased cellular differentiation.

Types of Necrosis

Patterns of cell death including Coagulative (ischaemia), Colliquative (brain), Caseous (tuberculosis), Fat (pancreatitis), and Fibrinoid (hypertension).

Dukes Classification

A staging system for colorectal cancer: A (limited to muscularis propria), B (breaches muscularis), C (lymph node involvement), and D (distant metastases).

Hesselbach’s Triangle

The anatomical region through which direct inguinal hernias protrude, bounded by the inferior epigastric artery, inguinal ligament, and rectus abdominis.

Calot’s Triangle

An anatomical space used to locate the cystic artery during cholecystectomy, bounded by the cystic duct, common hepatic duct, and the inferior border of the liver.

Breslow Thickness

The most important prognostic indicator for malignant melanoma, measuring the vertical depth of the tumour.

Phyllodes Tumour

A rare fibroepithelial breast neoplasia with malignant potential that often recurs locally if not excised with wide margins.

Acute Respiratory Distress Syndrome (ARDS)

A severe lung condition characterized by a $PO_2:FiO_2$ ratio of $<200 ext{ mmHg}$ and bilateral pulmonary infiltrates on chest X-ray.

Glasgow (Imrie) Score

A prognostic scoring system for acute pancreatitis; criteria include $PO_2 < 8 ext{ kPa}$, age $> 55$, glucose $> 10 ext{ mmol/L}$, and calcium $< 2 ext{ mmol/L}$.

Warthin Tumour

A benign adenolymphoma arising almost exclusively in the parotid gland, highly associated with cigarette smoking.

Reed-Sternberg Cells

Large, neoplastic giant cells with mirror-image nuclei and eosinophilic nucleoli pathognomonic for Hodgkin lymphoma.

Fournier Gangrene

A surgical emergency characterized by necrotizing fasciitis of the scrotum and perineum, often seen in diabetic patients.

Virchow’s Triad

Three factors predisposing to thrombus formation: endothelial injury, hypercoagulability, and altered blood flow (stasis or turbulence).

Anion Gap

Calculated as $(Na^+ + K^+) - (HCO_3^- + Cl^-)$; used to distinguish between different types of metabolic acidosis.

Stellate Ganglion

A sympathetic ganglion formed by the fusion of the inferior cervical and first thoracic ganglia, sitting anterior to the transverse process of $C7$.