Cell Injury and Adaptation Flashcards
• Hypertrophy –
increase in the size of an
organ without an increase in cell number
(hyperplasia)
Pure hypertrophy usually occurs only in
2
skeletal and cardiac muscle
Hyperplasia is the
increase in size of a tissue or organ due to an increased number of cells
Some hyperplasias are physiologic
3
– Erythroid bone marrow hyperplasia at high altitude
– Cyclic enlargement of the endometrium and breast during the menstrual cycle
– Regrowth of liver parenchyma after surgical excision is compensatory
Some hyperplasias are pathologic - (1)
epithelial hyperplasia caused by the human papilloma virus
HPV
Hyperplasia may be combined with hypertrophy
2
– In an enlarged uterus of pregnancy, myometrial smooth muscle cells are increased not only in number
(hyperplasia) but also in size (hypertrophy)
– In benign prostatic enlargement, there is both hyperplasia and hypertrophy of prostatic glands and smooth
muscle
EPITHELIAL HYPERPLASIA: ex
Papilloma
ENDOTHELIAL HYPERPLASIA:
ex
Pyogenic Granuloma
FIBROUS HYPERPLASIA:
ex (2)
Fibroma
Epulis Fissuratum
EPITHELIAL & FIBROUS HYPERPLASIA:
ex
INFLAMMATORY PAPILLARY HYPERPLASIA
OSSEOUS HYPERPLASIA:
ex (2)
SUB-PONTIC OSSEOUS HYPERPLASIA
Exostoses
GINGIVAL ENLARGEMENT (HYPERPLASIA) due to (2)
POOR ORAL HYGIENE AND DIABETES
DRUG-INDUCED GINGIVAL
ENLARGEMENT-
ex (3)
Procardia
Cyclosporin
Dilantin
GINGIVAL ENLARGEMENT (HYPERPLASIA) (8)
- Inflammatory hyperplasia
- Drug-induced enlargement –Calcium channel blockers, cyclosporine, dilantin
- Leukemic infiltrates
- Amyloid infiltration
- Klippel-Trenaunay-Weber syndrome
- Juvenile hyaline fibromatosis
- Cowden syndrome
- Wegener granulomatosis
CONDYLAR HYPERPLASIA
Idiopathic unilateral growth of the mandibular condyle
GYNECOMASTIA
HYPERPLASIA OF MALE BREAST
Atrophy is the
reduction in size of cells, tissues or organs
PATHOLOGIC ATROPHY
2
- Atrophy of skeletal muscle following denervation
* Atrophy of the brain due to ischemia
PHYSIOLOGIC ATROPHY
2
• Atrophy of the uterus after
pregnancy
• Involution of the thymus in early
adult life
PATHOLOGIC ATROPHY MAY
RESULT FROM: (6)
- Disuse
- Denervation
- Lack of trophic hormones
- Ischemia - reduction in blood supply
- Malnutrition
- Idiopathic –Parry-Romberg syndrome
Metaplasia is the
replacement of one mature cell type by another one.
METAPLASIA
It generally represents a change to a “—” cell type
tougher
Replacement of bronchial stratified columnar epithelium by squamous epithelium is an example of
squamous metaplasia that occurs in smokers
Intestinal metaplasia of the esophagus, called Barrett esophagus is caused by
chronic irritation by gastric juices in gastroesophageal reflux
Metaplasia is generally
reversible and the tissue reverts to its normal state after the irritant is removed
If the irritant persists, metaplasia may progress to
dysplasia and then to frank neoplasia
ADAPTIVE (4)
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 a “tougher” cell type
NON-ADAPTIVE (3)
- Agenesis
- Aplasia
- Hypoplasia
• Hypoplasia
is the incomplete development of
an organ
• The organ never reached its normal size
Dysplasia literally means
abnormal formation
• The term is used in many contexts
REVERSIBLE CHANGES
• Fatty Change - Liver
IRREVERSIBLE CHANGES
2
- Necrosis
* Apoptosis
NUCLEAR CHANGES THAT SIGNAL
CELL DEATH IN NECROSIS (3)
pyknosis
karyohexis
karyolysis
Pyknosis –
a small, dark
and shrunken nucleus
Karyorrhexis –
nuclear
fragmentation
Karyolysis –
dissolution
of the nucleus
THE CYTOPLASM TELLS YOU
HOW CELLS HAVE DIED
(2)
- Coagulation Necrosis
* Liquefaction Necrosis
• Coagulative necrosis –
typically seen in hypoxic injury (myocardial infarct)
• Liquefactive necrosis –
typically seen in bacterial infections and cerebral infarct
• Caseous necrosis –
necrotic tissue is converted into a cheesy mass (tuberculosis)
• Fat necrosis –
characteristically seen in acute pancreatitis
Coagulative necrosis –
typically seen in
hypoxic injury
myocardial infarct
Liquefactive necrosis –
typically seen in
bacterial infections and
cerebral infarct
Caseous necrosis –
necrotic tissue is
converted into
a cheesy
mass (tuberculosis)
Fat necrosis –
characteristically seen
in
acute pancreatitis
APOPTOSIS
• Programmed cell death occurs through activation of an internal suicide program
APOPTOSIS occurs with
CASPASES
APOPTOSIS
Selectively eliminates
unwanted cells with minimal disturbance to the surrounding cells
APOPTOSIS
The plasma membrane remains intact, but its structure is altered so that
it becomes a target for phagocytosis
APOPTOSIS
The dead cell is rapidly cleared before its contents have leaked out and therefore does not
elicit an inflammatory reaction
APOPTOSIS
Physiologic
(4)
• Programmed destruction of cells during embryogenesis • Hormone-dependent involution of tissues in the adult • Deletion of potentially harmful self-reactive lymphocytes • Cell death induced by cytotoxic T-cells (virally-infected or neoplastic cells)
APOPTOSIS
Pathologic
(4)
• If DNA repair mechanisms can’t cope with damage, the cells kills itself by apoptosis • Cell death in certain viral infections (hepatitis) • Pathologic atrophy in organs after obstruction • Cell death in tumors
Exogenous pigments
2
– Carbon - anthracosis
– Tattooing –skin and mucosal tattoos
Endogenous pigments (4)
– Lipofuscin
– Melanin –formed in melanocytes
– Hemosiderin –hemoglobin-derived
– Bilirubin
Pathologic calcification is the
abnormal deposition of calcium salts in tissue
Dystrophic calcification occurs in
nonviable or dying tissues in the presence of normal serum calcium levels
Metastatic calcification occurs in
viable tissues and is associated with hypercalcemia
