Growth, Cell death & Neoplasia Flashcards
Define multiplicative growth
Increase in number of cells by mitotic cell divisions
Define auxetic growth
Increase in size of individual cells eg. Skeletal muscle
Define accretionary growth
Increase in intercellular tissue components
Define atrophy
Decrease in size of an organ or cell either physiological or pathological
Define hyperplasia
Increase in cell number by mitosis, may be due to decreased apoptosis
Define hypertrophy
Increase in cell size without cell division, in permanent cells it is the only option for growth
Define metaplasia
Reversible transformation of one fully differentiated cell type into another. It is an adaptive response to environmental stress. eg squamous epithelium –> columnar epithelium in Barrett’s oesophagus
3 characteristics of dysplasia
Increased cell growth, presence of atypical morphology, decreased differentiation, often pre-neoplastic, may be reversible in early stage
3 differences between apoptosis and necrosis
Apoptosis natural, necrosis caused by external factors. Apoptosis usually beneficial, necrosis always detrimental.
Apoptosis no symptoms, necrosis evokes an inflammatory response.
5 types of necrosis
Gangrenous, coagulative, colliquative, caseous, fat necrosis
Define neoplasia
Abnormal, uncoordinated and excessive cell growth which persists when the stimulus is removed
Define a tumour
A lesion resulting from the autonomous and abnormal growth of cells which persists after the initial stimulus has been removed
Name 6 different shapes of tumours
Sessile, pedunculated, fungating, papillary, ulcerated, annular
4 histological differences of neoplasms to normal tissue
Increased mitotic activity, loss of cellular cohesion, loss of differentiation, nuclear enlargement
8 inducers of apotosis
Growth factor withdrawal, loss of matrix attachment, glucocorticoids, viruses, free radicals, ionising radiation, DNA damage, FAS ligand
4 inhibitors of apoptosis
Growth factors, cell matrix, sex steroids, some proteins
Describe the process of apoptosis
Degradation of cytoskeletal framework, DNA fragments, loss of mitochondrial function, nucleus shrinks (pyknosis) and fragments (karyorrhexis), cell shrinks but retains intact plasma membrane. Dead cells not phagocytosed break into apototic bodies - no inflammatory response.
What two factors are tumours classified according to?
Behaviour (benign or malignant) and histogenesis (cell of origin)
5 features of benign tumours
Close histological resemblance to parent tissue, non invasive, remain localised, slow growth, exophytic growth
5 features of malignant tumours
Variable resemblance to parent tissue, ability to invade and therefore metastasise, rapid growing, endophytic growth
5 clinical problems benign tumours can cause
Anxiety, pressure on surrounding structures, production of hormones, transformation into a malignant neoplasm, obstruction of the flow of fluid
7 clinical problems malignant tumours cause
Pressure on/destruction of adjacent tissue, secondary tumours, anxiety, pain, paraneoplastic effects, blood loss, obstruction of flow, production of a hormone
3 major histogenetic classifications
Epithelial, connective tissue, lymphoid/haemopoeitic organs
Define differentiation
The degree to which the tumour resembles histologically its cell of origin, it determines the tumour grade
