L2 - Terminology Flashcards
Define a cyst
cavity, epithelium lining, contain secretion - type epithelium dependent, watery - lining epithelium is serous, mucus - mucus secreting columnar epithelium
Define an Abscess
cavity, granulation tissue lining, contain pus (dead or dying neutrophil leukocytes
Define a granulation tissue
repair tissue, newly formed blood vessels, myofibroblasts
Define Granuloma
chronic inflammation, localised collection of mod macrophages (epithelioid histiocytes), may central area of necrosis, lymphocytes & plasma cells, pathogenesis - Type 4 delayed hypersensitivity, causes - TB & sarcoidosis
Define Apoptosis
regulated cell death, loss of specialised surface structures, cell volume reduction, chromatin condensation - chromatin aggregates peripherally under nuclear membrane, form cytoplasmic blebs & apoptotic bodies, phagocytosis of apoptotic bodies - macrophages
Define Necrosis
Morphologic changes follow cell death in living tissue, result from progressive degradative action of enzymes on the lethally injured cells, Subtypes (Coagulative necrosis, Liquefactive necrosis, Suppurative necrosis, Caseous necrosis, Fat necrosis, Gangrene)
Define the difference between apoptosis and necrosis with histology
Apoptosis: single cells affected within living tissue, tissue structure unaffected
Necrosis: sheets of cells dying together, tissue architecture is disrupted
Define the difference between apoptosis and necrosis with cytology
Apoptosis: Cells contract, increased density of cytoplasm & nucleus
Necrosis: Cells swell (oedema), loss of intracellular features
Define the difference between apoptosis and necrosis with ultrastructure
Apoptosis: Plasma membrane and mitochondria remain intact
Necrosis: Plasma membrane & internal membrane ruptured, mitochondria swell
Define the difference between apoptosis and necrosis with Dye exclusion
Apoptosis: : Dyes excluded
Necrosis: Dyes enter cells freely
Define the difference between apoptosis and necrosis with circumferences
Apoptosis: Dyes excluded
Necrosis: Never physiological
Define the difference between apoptosis and necrosis with effects on tissue
Apoptosis: No inflammation, rapid removal of dead cell leaving tissue architecture undisturbed
Necrosis: Evokes an acute inflammatory reaction, major disturbance of surrounding tissue
Define Hyperplasia
Increased no. cells, negative feedback control, tissue/organs go back to normal when demand is withdrawn
Define Neoplasia
increased no. cells, cells continue to grow/multiply, some genetic control on cell proliferation is lost, usually mutation in oncogenes or tumour suppressor genes
Define hyperplasia
Organ responds to increase demand by increase no. of cells, cells multiply (labile cells) like epithelial cells of gut
Define Hypertrophy
Organ responds to increase in demand by acquiring more organelles in cell cytoplasm, increase size of cells, cells can’t multiply (stable cells) like muscle cells
Define Atrophy
organs fully grow → denervation or lack of activity (immobilisation after fracture) → Reduce cell size → Shrink organ size
Define Aplasia
Organs never developed, example: fingers & appendix
Define metaplasia
Adapt to cell environment, change one adult cell type to another, example: squamous metaplasia in cervix, bronchus, Barrett’s metaplasia of oesophagus
Define dysplasia
premalignant change - disorganised growth, changes in cellular levels, variability in size & shape (pleomorphism), increased nuclear cytoplasmic ratio, darkly staining nuclei (hyperchromasia), increased mitotic activity
Define In-situ carcinoma
full thickness dysplasia of epithelium, confined to epithelium, don’t invade basement membrane
Define invasive carcinoma
full thickness dysplasia of epithelium, neoplastic cells invade basement membrane
Define Carcinoma
malignant tumour of epithelial differentiation, type of epithelial effects further division (squamous cell carcinoma, adenocarcinoma, urothelial carcinoma)
Define Sarcoma
malignant tumour of mesenchymal differentiation, type of cells sarcomas further subdivided (Fibrosarcoma, Leiomyosarcoma, Rhabdomyosarcoma, Liposarcoma, Chondrosarcoma, Osteosarcoma etc)
Define Hamartoma
developmental malformation, normal tissues present, not laid properly - lumps, examples: birth marks with blood vessels or hair follicles
Define Teratoma
tumour, totipotent germ cells, cells differentiate → bone, cartilage, muscle & epithelial cells, not normally present, examples: teratoma in ovary or testis w/ bone or cartilage
Define Benign
Small, well defined borders, low mitotic count, well differentiated, localized to site of origin, don’t invade
Define Malignant
Larger, irregular borders, high mitotic count, variable differentiation, spread to distant site (metastasis), invade: basement membrane, vascular channels, perineural neural invasion
Define Adenoma
benign tumour, formation of glands
Define Papilloma
benign tumour, finger-like/papillary structures
Define Differentiation
benign, well differentiated malignant tumour sim to normal counterpoint, example: fibroadenoma to normal lobules of breast
Define Anaplasia
No resemblance to normal counterpart, malignant tumours have bad prognosis
Define Grading
how far the tumour is differentiated
Define Staging
how far tumour spread, size of primary tumour, lymph node involvement, distant metastasis, UICC - TNM staging (T - Primary Tumour, N - Lymph Node, M - Distant Metastasis)
What are the key differences between acute and chronic inflammation?
Acute: rapid onset, short duration, mainly neutrophils
Chronic: slow onset, long duration, lymphocytes, plasma cells, macrophages, tissue destruction and repair
What are the cardinal signs of acute inflammation?
Redness (rubor), Heat (calor), Swelling (tumor), Pain (dolor), Loss of function (functio laesa)
What are the systemic effects of acute inflammation?
Fever, Malaise, Leukocytosis, Elevated acute-phase proteins (e.g., CRP, fibrinogen)
What are the possible outcomes of acute inflammation?
Resolution, Abscess formation, Chronic inflammation, Healing by fibrosis
What are the roles of macrophages in chronic inflammation?
Phagocytosis, Antigen presentation, Cytokine secretion (IL-1, TNFα), Stimulate fibroblasts and angiogenesis
Define healing by first intention
Healing of a clean surgical wound where edges are closely apposed → minimal scarring, minimal granulation tissue
Define healing by second intention
Healing of a large or infected wound → more granulation tissue, wound contraction, larger scar
What is meant by ‘organisation’ in pathology?
Replacement of dead tissue by granulation tissue → eventually fibrous scar
What are labile, stable, and permanent cells in terms of regenerative capacity?
Labile: continuously divide (e.g., skin, gut epithelium)
Stable: normally quiescent, can divide (e.g., liver)
Permanent: cannot divide (e.g., neurons, cardiac muscle)
What is the function of myofibroblasts in wound healing?
Contract the wound edges and deposit collagen → scar formation
What causes caseous necrosis and what is its appearance?
Cause: tuberculosis
Appearance: soft, cheese-like, granulomatous inflammation with central necrosis
