cell injury and adaptation Flashcards
Stages in the Cellular Response to Stress and Injury diagram
HYPERTROPHY
Pure hypertrophy occurs where?
• Hypertrophy –increase in the size of an organ without an increase in cell number
(hyperplasia)
• Pure hypertrophy usually occurs only in skeletal and cardiac muscle
cardiac hypertrophy
due to hypertension, done to increase force of contraction
increased size can lead to ischemia resulting in MI/ cell death
HYPERPLASIA
types?
Hyperplasia is the increase in size of a tissue or organ due to an increased number of cells
can be physiologic, pathologic or combined with hypertrophy
physiologic hyperplasia examples
– 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
pathologic hyperplasia example
epithelial hyperplasia caused by the human papilloma virus
HPV
combo hypertrophy and plasia examples
– 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
(Squamous) Papilloma
epithelial hyperplasia caused by HPV on lips
pyogenic granuloma
epithelial hyperplasia presenting as an ulcerative nodule on gingiva
fibroma
sessile nodule on the tongue, represents a fibrous hyperplasia
epulis fissuratum
represents a fibrous hyperplasia, found with ill-fitting dentures
inflammatory papillary hyperplasia of the palate
represents a combo epithelial and fibrous hyperplasia
sub-pontic osseous hyperplasia
osseous hyperplasia, bone forms under pontic
exotoses
represent osseous hyperplasia
gingival enlargement, common causes?
form of hyperplasia often due to poor hygiene or diabetes
drug induced gingival enlargement
side effect of some drugs
procardia- ca channel block for hypertension
cyclosporin- immunosuppressant for transplants
dialntin/phentoin- anti-seizure med
possible causes of gingival enlargement
- Inflammatory hyperplasia
- Drug-induced enlargement
- Leukemia infiltrates
- Amyloid infiltration
- Klippel-Trenaunay-Weber syndrome
- Juvenile hyaline fibromatosis
- Cowden syndrome
- Wegener granulomatosis
condylar hyperplasia
Idiopathic unilateral growth of the mandibular condyle
hyperplastic dental follicle
enlarged follicle of non erupted tooth, would req a biopsy to diagnose
gynecomastia
hyperplasia of the male breast, due to increased estrogen or increased hormone secreting tumor
ATROPHY
• Atrophy is the reduction in size of cells, tissues or organs
types of atrophy
pathologic and physiological
PATHOLOGIC ATROPHY examples
- Atrophy of skeletal muscle following denervation
* Atrophy of the brain due to ischemia
PHYSIOLOGIC ATROPHY examples
- Atrophy of the uterus after pregnancy
* Involution of the thymus in early adult life
PATHOLOGIC ATROPHY MAY RESULT FROM:
Disuse • Denervation • Lack of trophic hormones • Ischemia - reduction in blood supply • Malnutrition • Idiopathic –Parry-Romberg syndrome
thenar atrophy
mm atrophy caused by carapl tunnel= lack of medial nn inn
denervation atrophy in skeletal mm
loss of inn results in the decrease in mm cell size
atherosclerotic disease of the brain
will cause atrophy of the brian = widened gyri and narrow sulci
edentulous atrophy
loss of alveolar bone without teeth
PARRY ROMBERG SYNDROME
idiopathic PROGRESSIVE HEMIFACIAL ATROPHY= will stabilize and can be corrected with surgery
METAPLASIA
• Metaplasia is the replacement of one mature cell type by another one.
• It generally represents a change to a “tougher” cell type
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
smokers metaplasia
• Replacement of bronchial stratified columnar epithelium by squamous epithelium is an example of squamous metaplasia that occurs in smokers
can lead to dysplasia and become malignant = squamous cell carcinoma
barrets esophagus
• Intestinal metaplasia of the esophagus, called Barrett esophagus is caused by chronic irritation by gastric juices in gastroesophageal reflux
squamous to columnar in the lower esophagus, better able to tolerate acids
can progress to dysplasia and become and adenocarcinoma
NECROTIZING SIALOMETAPLASIA
on the palate, a reactive condition that will heal on its own
appearance of epithelial tissue invading surrounding tissue similar to cancer
HOW CELLS RESPOND TO NON-LETHAL INJURY
adaptive and non-adaptive
adaptive changes
hyperplasia
hypertrophy
metaplasia
atrophy
non adaptive changes
mainly developmental or genetic
agenesis
aplasia
hypoplasia
agenesis
complete non-dev of a cell or organ
examples: mandible, tooth roots, multiple teeth, etc
aplasia/hypoplasia
• Hypoplasia is the incomplete development of
an organ
• The organ never reached its normal size
TREACHER COLLINS SYNDROME
MANDIBULO-FACIAL DYSPLASIA, hypoplasia of the mandible
Pierre robin syndrome
hypoplasia/ aplasia of the mandible
regional odotnodysplasia
certain quadrants m ay be affected with the hypoplasia/aplasia of teeth
“ghost teeth” present
also represents a dysplasia= abnormal formation
DYSPLASIA
DYSPLASIA
• Dysplasia literally means abnormal formation
• The term is used in many context
What does EPITHELIAL DYSPLASIA potentially lead to? only this?
potential to lead to malignancies and cancer
only epithelial dysplasia indicates pre malignancy
ECTODERMAL DYSPLASIA
genetic/developmental
abnormal formation of ectoderm derivatives (teeth, hair, skin, sweat glands, etc.)
FIBRO-OSSEOUS DYSPLASIA at tooth root radiography
mixed lucent and opaque radiograph appearance, present at apex
fibrous dysplasia of the face
usually with maxilla or mandible, become enlarged unilaterally
developmental
seen radiographically
type I dentin dysplasia
abnormal root dentin formation
Stages in the Cellular Response to Stress and Injury diagram
reversible change in the liver
fatty change, due to alcohol abuse, accumulation of fat cells in the liver
irreversible changes
cell death: apoptosis and necrosis
cell death mechanism diagrams
apoptosis: apoptotic formed and digested by phagocytes= clean
necrosis: lysosomal membranes break and contents leak digesting cell contents and causing local inflammatory response
nuclear signals of necrosis
- Pyknosis –a small, dark and shrunken nucleus
- Karyorrhexis –nuclear fragmentation
- Karyolysis –dissolution of the nucleus
what tells you how cells die?
cytoplasm
types of necrosis, usually seen with?
- 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
liquefactive necrosis
causeous necrosis
APOPTOSIS
- Programmed cell death occurs through activation of an internal suicide program
- CASPASES enzymes mediate this
- Selectively eliminates unwanted cells with minimal disturbance to the surrounding cells
- The plasma membrane remains intact, but its structure is altered so that the 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
types of apoptosis
physiologic and pathologic
Physiologic apoptosis examples
- 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)
Pathologic apoptosis examples
- 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
from external environment
– Carbon - anthracosis, blackened lungs
– Tattooing –skin and mucosal tattoos, amalgam tats
Endogenous pigments
– Lipofuscin (aging)
– Melanin –formed in melanocytes
– Hemosiderin –hemoglobin-derived
– Bilirubin, excreted in bowels/urine
PATHOLOGIC CALCIFICATION
• Pathologic calcification is the abnormal deposition of calcium salts in tissue, can be dystrophic ot metastic
dystrophic calcification
• Dystrophic calcification occurs in nonviable or dying tissues in the presence of normal serum calcium levels
metastatic calcification
Metastatic calcification occurs in viable tissues and is associated with hypercalcemia
cardiac hypertrophy
epithelial hyperplasia: papilloma
ENDOTHELIAL HYPERPLASIA:
Pyogenic Granuloma
FIBROUS HYPERPLASIA:
Fibroma
FIBROUS HYPERPLASIA:
Epulis Fissuratum
EPITHELIAL & FIBROUS HYPERPLASIA:
INFLAMMATORY PAPILLARY HYPERPLASIA
OSSEOUS HYPERPLASIA:
SUB-PONTIC OSSEOUS HYPERPLASIA
OSSEOUS HYPERPLASIA:
Exostoses
GINGIVAL ENLARGEMENT (HYPERPLASIA)
condylar hyperplasia
hyperplastic dental follicle
brain atrophy, atherscerlotic disease
parry romberg syndrome
barretts esphogus, metaplasia
NECROTIZING SIALOMETAPLASIA
mandibular agenesis
root agenesis
MANDIBULO-FACIAL DYSPLASIA
TREACHER COLLINS SYNDROME
APLASIA/HYPOPLASIA
REGIONAL ODONTODYSPLASIA
epithelial dysplasia
ectodermal dysplasia
fibro ossesoius dysplasia
fibrous dysplasia
dentin dysplasia type I
how are these nuceli identified? what is happening?
pyknosis and karyohexis, cell death
