Cell adaption and necrosis Flashcards
What is cell adaption?
prolonged exposure of cell to pressure or toxin results in change in cell
if pressure: cells get big
If toxin: cells change shape
What are the 6 ways that cells adapt to change?
atrophy, hypertrophy, hyperplasia, metaplasia, dysplasia and anaplasia
Define atrophy
decrease in the size of a tissue, organ or the entire body
can be physiologic v. pathologic atrophy
examples of physiologic atrophy?
thymus undergoing involution
ovaries, uterus and breasts after menopause
atrophic bones and muscles in the elderly become thin and prone to fracture
examples of pathologic atrophy?
alzheimer dementia,
ischemic organs-typically small,
testicular atrophy
Define hypertrophy
increase in the size of tissue due to enlargement of individual cells
can be physiologic or pathologic
examples of physiologic hypertrophy?
enlargement of muscles in body builders
examples of pathologic hypertrophy?
hypertrophy of the heart occurs as an adaption to increase workload
When do we usually see concentric hypertrophy of the left ventricle? why?
in HTN
it is an adaptive response to left ventricular pressure overload
What can be seen in hypertrophy cardiomyopathy?
banana septum
Define hyperplasia
an increase in the number of cells which causes enlargement of tissues
Can hyperplasia and hypertrophy be seen together?
yes, in pregnancy
hyperplastic prostate
Examples of hyperplastic process?
endometrial hyperplasia due to estrogens
Example of a disease where hyperplasia is seen?
hyperplastic polyps of the colon or stomach
Define metaplasia
an adaptive change of one cell type for another cell type to suit the environment
reversible but can also progress to dysplasia
Examples of metaplasia
squamous metaplasia of the bronchial epithelium due to smoking
gastric or glandular metaplasia of GE junction barrett esophagus
Define dysplasia
disordered growth of tissues resulting from chronic irritation or infection
considered a precancerous condition
Example of dysplastic change?
detection of cervical dysplasia on PAP smear
there is an association of dysplasias and cervical cancer with HPV
With dysplasia …..gets large and …starts to shrink
nucleus
cytoplasm
What does hyperchromatic mean?
stains darker
define anaplasia
undifferentiated and uncontrolled growth of cells, hallmark of malignant transformation
Anaplasia is also called??
malignancy, carcinoma, cancer, neoplasm
neoplasm means?
new growth
Examples of anaplasia?
squamous cell carcinoma of the cervix, cancer of the lung, malignant melanoma
What color can malignant melanoma be?
red, white, blue, black or brown
Which cancer are known as the silent killers?
renal cell carcinoma, ovarian, pancreatic, glioblastoma
Hallmarks of anaplasia?
- cells and nuclei display marked cellular pleomorphism
- nuclei are irregular and hyperchromatic
- high nuclear/cytoplasmic ratio (about 1:1)
- large nucleoli present within nucleus
- large numbers of abnormal mitotic figures
Define pleomorphism
variation in size and shape
Should you ever see mitotic figures in normal tissue?
NO
What is cell necrosis?
death of cells or groups of cells within a living organism
What is the difference between necrosis and autolysis?
necrosis: seen in living
autolysis: seen in tissues after death
Name the 4 types of necrosis
coagulative
liquefactive
caseous
fat
What is coagulative necrosis?
most common type of necrosis
occurs when cell proteins are altered or denatured (like cooking eggs)
cell outlines preserved and cytoplasm finely granular
Examples of coagulative necrosis?
typically occurs in solid internal organs i.e. heart, kidney, spleen, liver
most often caused by anoxia, ex. heart tissue undergoing MI
What is anoxia?
lack of blood supply
What is liquefactive necrosis?
dead cells liquify under the influence of certain cell enzymes, tissue becomes soft and gel like
Examples of liquefactive necrosis?
most often occurs in the brain where the brain cells lose their contours and liquify, typical of brain infarcts
can also be seen in bacterial infections (abscesses in the lungs)
What is caseous necrosis?
a form of coagulative necrosis in which a thick, yellowish, cheesy substance forms
Examples of caseous necrosis?
typically found in TB, characterized by the development of lung granulomas inside of which can be found caseous necrosis- Ghon complex
can also be seen in some fungal infections
What is fat necrosis?
a specialized form of liquefaction necrosis, caused by the action of lipolytic enzymes
Examples of fat necrosis
limited to fat tissue, usually around the pancreas. Enzymes are released into the adjacent fat tissue, usually after rupture of the pancreas, causing degradation of fat
Wet v. dry gangrene
gangrene is bacterial infection of necrotic tissue
Wet: bacterial infection of coagulated tissue leads to inflammation and secondary liquefaction
Dry: necrotic tissue dries out and becomes black and mummified
What conditions can contribute to gangrene?
often occur after infarction of the intestines of in a limp, usually caused by atherosclerosis or DM
What is dystrophic calcifications?
necrotic tissue attracts calcium salts and freq. undergoes calcification, refers to the macroscopic deposition of calcium in injured or dead tissues
Examples of dystrophic calcification?
- calcification in atherosclerotic CA contributes to narrowing of the vessels
- calcifications of the mitral or aortic valves leading to impeded blood flow (stenosis)
- Calcifications seen around breast cancer
- infant periventricular calcifications seen in congenital toxoplasmosis
what is metastatic calcifications?
reflects deranged calcium metabolism, usually associated with increased serum calcium levels, leading to deposition of calcium in other locations
Examples of metastatic calcifications?
seen in various disorders including hyperparathyroidism, vit D toxicity and chronic renal failure
formation of Ca stones in sites such as gallbladder, kidney and bladder are due to precipitation of salts from solutions into tissues
