Atrophy, Hypertrophy, Metaplasia and Dysplasia Flashcards
which 2 processes casue increased growth
hypertrophy and hyperplasia.
define hypertrophy
increase in size of a tissue cause by an increase in size of the constituent cells
(the size of the cell/tissue/organ increases without an increase in the number of cells)
where does hypertrophy occur
in organs where cells cannot divide
eg skeletal muscle in athletes
define hyperplasia
: increase in size of a tissue caused by an increase in number of the constituent cells
(The increased growth is the result of an increase in the number of cells)
where does hyperplasia occur
in organs where cells can divide
eg benign prostatic hyperplasia
define atrophy
decrease in size of a tissue caused by a decrease in number of the constituent cells or a decrease in their size
examples of atrophy
alzhemiers demetia
what is mixed hypertrophy/hyperplasia
increase in the size of an organ due to increase in size and number of its constituent cells
where does mixed hypertrophy/hyperplasia occur
in organs where cells can divide
eg smooth muscle cells in uterus during pregnancy
define metaplasia
change in differentiation of a cell from one fully-differentiated type to a different fully-differentiated type
(the reversible transformation of one mature cell type into another fully differentiated cell type).
what usually causes metaplasia
a consistent change in the environment of an epithelial surface
examples of metaplasia
barrets oesophagus
define dysplasia
imprecise term for the morphological changes seen in cells in the progression to becoming cancer
(a premalignant condition characterised by increased growth, cellular atypia and decreased differentiation).
what is dysplasia usually defined by
features seen by H&E on light microscope
describe spectrum of dysplasia
mild
moderate
severe
carcinoma in situ
invasive cancer
