Cell Injury and Adaptation Flashcards
how do cells adapt to stress
-hypertrophy
- hyperplasia
- atrophy
- metaplasia
what is hypertrophy
increase in the size of an organ without an increase in cell number
where does hypertrophy usually only occur
skeletal and cardiac muscle
what does hypertrophied cardiac muscle look like
increased size between fascicles and blood supply is further away from fascicles
what is hyperplasia
increase in size of a tissue or organ due to an increased number of cells
what are examples of physiologic hyperplasia
erythroid bone marrow hyperplasia at high altitude
- cyclic enlargement of the endometrium and breast during menstrual cycle
- regrowth of liver parenchyma after surgical excision
what is an example of pathologic hyperplasia
epithelial hyperplasia caused by the human papilloma virus
what are examples in which hyperplasia is combined with hypertrophy
- enlarged uterus of pregnancy, myometrial smooth muscle cells are increased not only in number but also in size
- in benign prostatic enlargement there is both hyperplasia and hypertrophy of prostatic glands and smooth muscle
what is a papilloma formed due to
epithelial hyperplasia
what are pyogenic granulomas formed due to
endothelial hyperplasia
what are fibromas formed due to
fibrous hyperplasia
what is epulis fissuratum formed due to
fibrous hyperplasia
what is inflammatory papillary hyperplasia formed due to
epithelial and fibrous hyperplasia
what is sub pontic osseous hyperplasia formed due to
osseous hyperplasia
what are exostoses formed due to
osseous hyperplasia
what is gingival enlargement due to
hyperplasia
when is epulis fissuratum seen
in denture patients with ill fitting dentures
when is inflammatroy papillary hyperplasia seen
in denture patients with ill fitting dentures
when is sub pontic osseous hyperplasia seen
in bridge cases on the tooth that has the bridge over it
what is gingival hyperplasia due to
- poor oral hygiene
- DM
what does cyclosporin do and what is its side effect
- causes gingival enlargement
- immunosuppressant
what does procardia do and what is its side effect
-hypertensive medication- calcium channel blocker
causes drug induced gingival enlargement
what does dilantin do and what is its side effect
- treats seizures
- causes gingival enlargement
what disorders cause gingival enlargement
- leukemic infiltrates
- amyloid infiltration
- kippel- Trenaunay Weber syndrome
- juvenile hyaline fibromatosis
- cowden syndrome
- wegener granulomatosis
what is condylar hyperplasia
idiopathic unilateral growth of the mandibular condyle
- can cause open bite
how does a hyperplastic dental follicle present on an xray
pericoronal radiolucency
what causes gynecomastia - hyperplasis of male breast
- seen in puberty
- ketoconazole (anti fungal agent)
- lytic tumir
- pituitary gland tumor
- testes tumor
what is atrophy
reduction in size of cells, tissues or organs
what are examples of pathologic atrophy
atrophy of skeletal muscle following denervation
- atrophy of the brain due to ischemia
what are examples of physiologic atrophy
atrophy of the uterus after pregnancy
- involution of the thymus in early adult life
pathologic atrophy results from:
- disuse
- denervation
- lack of trophic hormones
- ischemia
- malnutrition
- idiopathic - parrry -romberg syndrome
what happens in parry romberg syndrome
progressive hemifacial atrophy
what is metaplasia
replacement of one mature cell type by another one
- changes to a tougher cell type
what is the metaplasia example in smokers
replacement of bronchial stratified columnar epithelium by squamous epithelium
what is an example of metaplasia in acid reflux
intestinal metaplasia of the esophagus called Barrett esophagus is caused by chronic irritation by gastric juices in GI reflux
metaplasia is generally _____ and the tissue ______ after the irritant is removed
reversible; reverts to normal
if the irritant persists, metaplasia may progress to:
dysplasia
where is necrotizing sialometaplasia seen
on hard palate, bi laterally or unilaterally
what two mechanisms do cells use to respond to non lethal injury
adaptive and non adaptivr
what are examples of adaptive mechanisms
- hyperplasia is an increase in cell numbers
- hypertrophy is an increase in cell size
- atrophy is the reduction in cell size
- metaplasia is a change to tougher cell type
what are examples of non adaptive mechanisms
agenesis
- aplasia
- hypoplasia
what is an example of agenesis
congenitally missing teeth
what is hypoplasia
the incomplete development of an organ
what happens in treacher collins syndrome
hypoplastic mandible
what happens in pierre robin syndrome
aplasia/hypoplasia
what is regional odontodysplasia and what is the disease classified as
aplasia/hypoplasia
- idiopathic
- “ghost teeth” in a section of the jaw
what are “ghost teeth” in a section of the jaw pathognomonic for
regional odontodysplasia
what does dysplasia mean
abnormal formation
what does ectodermal dysplasia affect
things that derive from ectoderm -> nails, hair, sweat glands
how does fibro- osseous dysplasia present on a radiograph
radiolucent and radiopaque periapical lesion
what is enlargment of the mandible caused by
fibrous dysplasia
what does dentin dysplasia type I affect
- altered growth of dentin
- affects radicular dentin
what are the two types of cell death
necrosis and apoptosis
what is an example of a reversible change
fatty change in liver
what are examples of irreversible changes
necrosis
apoptosis
what is pyknosis
a small dark and shrunken nucleus
what is karyorrhexis
nuclear fragmentation
what is karyolysis
dissolution of the nucleus
where is coagulative necrosis seen
hypoxic injury - MI
when in liquefactive necrosis seen
in bacterial infections and cerebral infarct
when is caseous necrosis seen
tuberculosis
when is fat necrosis seen
acute pancreatitis
what is apoptosis
programmed cell death occurring through activation of an internal suicide program
what controls apoptosis
caspases
what does apoptosis do
selectively eliminates unwanted cells with minimal disturbance to the surrounding cells
what is the process of apoptosis
- the plasma membrane remains intact but its structure is altered so that it becomes a target for phagocytosis
- the dead cell is rapidly cleared before its contents have leaked out and therefore does not elicit an inflammatory reaction
what is physiologic apoptosis
- programmed destruction of cells during embryogenesis
- hormone dependent involution of tissues in the adult
- deletion of potenially harmful self reactinve lymphocytes
- cell death induced by CTLs
what are pathologic apoptosis examples
- if DNA repair mechanisms cant cope with damage the cells kills iteself
- cell death in certain viral infections
- pathologic atrophy in organs after obstruction
- cell death tumors
what are exogenous pigments
-carbon- anthracosis
- tatooing- skin and mucosal tissues (amalgam tatto)w
what are endogenous pigments
- lipofuscin
- melanin
- hemosiderin
- bilirubin
what is pathologic calcification
abnormal deposition of calcium salts in tissues
where does dystrophic calcification occur
in nonviable or dying tissues in the presence of normal serum calcium levels
where does metastatic calcification occur
in viable tissues and is associated with hypercalcium
