Cell Pathology Flashcards
(108 cards)
Define atrophy
- Shrinkage in the size of a cell and consequently the size of a whole organ, by the loss of cell substance
- We see a decrease in weight of an atrophic organ
Define hypertrophy
- Increase in the size of a cell and consequently the size of a whole organ
- Physiological or pathological
- important because muscle cells (skeletal and cardiac) cannot divide so an increase in cell size is the only way in which an organ can get bigger
Define hyperplasia
- Increase in the number of cells in an organ
- Physiological or pathological
Define metaplasia
- Reversible change in which one normal adult cell type (mature cell) is replaced by another (normal adult cell replacement)
- Physiological or pathological
Define dysplasia
- Precancerous cells which show the genetic and cytological features of malignancy but do not invade the underlying tissue (does not invade through the basal lamina)
- bridge between normality and cancer
Examples of atrophy
- Gastric atrophy causing pernicious anaemia (anaemia resulting from vitamin B12 deficiency)
- Posterior cortical atrophy from the loss of neurones in Alzheimer’s disease
Examples of hypertrophy
Physiological: muscle hypertrophy in the uterus during pregnancy
Pathological: left ventricular hypertrophy in response to hypertension
Examples of hyperplasia
Physiological: oestrogen-induced endometrial hyperplasia
Pathological: benign prostatic hyperplasia, carcinoma
Examples of metaplasia
Physiological: metaplasia in the cervix
Pathological: Barrett’s Oesophagus (columnar lined oesophagus)
Examples of dysplasia
- Cervical intraepithelial neoplasia
- Patients with Barrett’s oesophagus are associated with a much greater oesophageal cancer risk because metaplasia is typically followed by dysplasia
Light microscopic changes associated with reversible cell injury
- fatty changes (fat accumulation in cells=fatty globules)
- cellular swelling (ballooning)
Light microscopic changes associated with irreversible cell injury
-The different types of necrosis
Define coagulative necrosis
- substance changes but the shape of the molecule does not change
- tissue retains structure after coagulation and can be recognised (nuclei gone and inflammatory cells present)
- myocardial infarction example
Define liquefactive necrosis
- tissue broken down leaving empty space which fills with fluid (tissue is totally liquefied)
- identification only from cells surrounding it (empty space)
- old cerebral brain infarct example
Define caseous necrosis
-form of granulomatous inflammation
-characteristic ‘cheesy’ appearance where
necrotic area becomes granular
-tissue cannot be recognised from structure
-associated with pulmonary tuberculosis
Define fat necrosis
- breakdown of fat cells by lipase release or trauma (significantly severe fat trauma)
- release of lipases digests the fat and hydrolyses the triglycerides into free fatty acids and glycerol
- free fatty acids combine with calcium in ECF forming calcium fat salts which deposit themselves
- associated with acute pancreatitis
Define necrosis
Confluent cell death associated with inflammation
Define apoptosis
Programmed cell death of single cells, not associated with inflammation
-normal in organism’s growth and development
Features of apoptosis
- active (energy dependent=requires ATP hydrolysis)
- physiological and pathological
- not associated with inflammation (no bystander damage to healthy tissue)
Features of necrosis
- cellular reaction of inflammation
- not just single cells (areas)
- not energy dependent
- always pathological
Define necroptosis
Programmed cell death associated with inflammation
Features of necroptosis
- energy dependent
- halfway between apoptosis and necrosis
- many causes including viral infection
- generally occurs in pathological circumstances
Causes of cell injury
G=genetic defects
I=infectious agents (bacteria, viruses, multicellular parasites)
N=nutritional imbalances
C=chemical agents (includes iatrogenic injury resulting from the drugs/medication doctors give)
H=hypoxia
A=aging
P=physical agents (eg: gunshot wound, trauma etc)
I=immunological reactions (autoimmune disease where the body attacks itself=conditions include rheumatoid arthritis)
What causes cell adaptation?
- stress on cells of increased demand/load
- cell remains in equilibrium but works in newly adapted state