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