Path Flashcards
In response to systemic hypertension, cardiac myocytes will undergo what cellular adaptation process?
Hypertrophy: can’t undergo hyperplasia because they are an established tissue.
Increase in organ size is accomplished by what 2 cell adaptation processes?
Hypertrophy, hyperplasia. Generally both are involved, like the uterus during pregnancy.
Which involves gene activation? Hypertrophy or hyperplasia?
Hypertrophy: gene activation, increased protein synthesis, and production of organelles.
Bigger cells, gotta fill it up.
HYPERPLASIA involves new cells generated from adult stem cells.
Pathologic hyperplasia (like endometriosis) can lead to _____________, and eventually neoplasia.
Dysplasia: abnormale growth of cells.
Decrease in stress on an organ will cause that organ to undergo……
Atrophy.
What is an indicative factor of atrophy in histology?
Autophagic vacuoles within the cell (stain yellow a lot of times)
A change in cell type based on new stress factors is called__________.
Metaplasia.
Metaplasia is ALWAYS _______________, and ALMOST ALWAYS_______________.
Metaplasia is always PATHOLOGIC, and almost always REVERSIBLE.
The process in which residual tissue grows after removal or loss of part of an organ is called_______________. Is this physiologic or pathologic?
Compensatory hyperplasia: physiologic.
Most forms of pathologic hyperplasia are caused by______________.
Excessive hormonal or growth factor stimulation.
Example:
There is a fine balance between estrogen and progesterone in the menstruation. Throw this off, and the endometrium may grow abnormally, causing abnormal bleeding.
Is wound healing an example of hyperplasia?
Yes. Rapidly proliferating cell population.
The degradation of cellular proteins occurs by what pathway?
Ubiquitin-proteosome
The mechanism of atrophy consist of a combination of _________________, and ______________ in cells.
Decreased protein synthesis (due to decreased metabolic activity) and increased protein degradation (via autophagy….proteosome)
Why is the metaplastic change from respiratory epithelium to squamous epithelium in the lungs bad? Doesn’t the squamous epithelium withstand the environmental stress better?
Yes, but the function of respiratory epithelium is lost. No cilia or mucous.
What else, other than smoking, can inside squamous metaplasia in the lungs?
Vitamin A deficiency. - Vitamin A is necessary for the differentiation of epithelial types.
Osteogenic metaplasia. WTF is that…>?
Bone is occasionally formed in tissues, specifically at the focal point of an injury.
What causes cell injury? (2 things)
- Direct injury
2. Stress so severe, or for such a long duration that cells can no longer adapt.
2 types of cell death?
Apoptosis/Necrosis
2 phenomena characterize irreversible cell damage. Describe them.
- Inability to correct mitochondrial damage (lack of ox phos and ATP generation)
- Extensive membrane damage
What are the 2 main morphologic correlates of REVERSIBLE CELL INJURY? What is the physiology behind that?
Cell Swelling and fatty change. (remember… they’re reversible.)
- Cell swelling due to failure of energy-dependent ion pumps in the plasma membrane. No fund/osmotic homeostasis.
- Fatty change: hypoxic damage/ toxic damage, etc…
The first manifestation of all forms of injury to cells is…….
Swelling. Can see with a light microscope or on a gross scale.
What is the histological landmark for cell swelling and fatty change?
1) Membrane: blebbing, distortion of cilia,
2) vacuoles in the cells, mostly cardiac myocytes or liver.
What color does RNA stain in H&E?
Blue. RNA is basophilic.
What are the histological characteristics of necrotic tissue?
What 3 things happen to the nuclei of necrotic cells?
Increased eosinphilia.
“moth eaten” with vacuoles.
Pyknosis - nuclear shrinkage
Karyorrhexis - pyknotic nucleaus fragments
Karyolysis - dissolution of the nucleus (no more basophilia due to RNA b-down)
Which type of necrosis can only be discovered upon histological examination?
Fiibrinoid.
Most organs (except the brain) undergo what type of necrosis (post-infarct).
Coagulative necrosis
Describe coagulative necrosis.
Tissue form remains.
Wedge shaped.
Occurs in every organ but the brain.
Microscopic: anucleate ghost cells.
If an abscess has pus in it, what do you do?
Drain the abscess and culture the pus. Pus is indicative of infection.
Gangrenous necrosis is what?
Coagulative necrosis of the extremities, esp. feet.
How does fat necrosis occur?
Acute pancreatitis. Pancreatic lipases are released into the peritoneal cavity. They liquify the membranes of fat cells, and lipase’s split the TGs into FA’s. The FA’s combine with calcium to form white chalky areas.
If an area of caseous necrosis is closed off by a distinctive inflammatory border, it is called a……
Granuloma.