Week 5 Introduction to Cell Injury Lecture Flashcards
Pathology
study of disease processes over time; a series of sequential stages from normal to abnormal
etiology
the cause of the disease; the initiating event or insulting agent and its related risk factors
pathogenesis
mechanisms involved in the transition from normal to abnormal
clinical expression of the disease
signs and symptoms due to cell injury
An individual arrives at the ER with chest pain, shortness of breath, and he dies shortly after being admitted. After examining prior medical records it was noted that he had chronically high cholesterol and blood pressure. Upon autopsy it was determined his death was due to myocardial infarction due to a clot in his coronary arteries caused by plaque build up. What was this pts: etiology, clinical expression of disease and pathogenesis
Clinical expression: chest pain, SOB, death Etiology: high cholesterol, high BP Pathogenesis: plaque buildup in the artery and subsequent clot
in general, when is cell injury reversible? irreversible?
reversible: mild/transient injurious stimulus irreversible: severe and/or progressive injurious stimulus
what are some ways cells can adapt to stress?
changes in cell size, cell number, cell type/differentiation
what is hypertrophy?
increase in cell size
what is hyperplasia?
increase in cell number
How do cells increase in size?
increased gene activation, protein and organelle synthesis
how to cells increase in number?
more/new cells produced from stem cells
When do we see hyperplasia and hypertrophy occurring together? give an example?
in general, hyperplasia and hypertrophy occur together. Ex: the uterus during pregnancy
when do we see hypertrophy but NOT hyperplasia? give examples (2)
when cells are able to grow but not divide. this occurs in skeletal muscle cells and cardiac muscle cells
what is aplasia?
failure of cell division during embryogenesis (the cells are not there)
what is hypoplasia?
decrease in cell production during embryogenesis; resulting in small organ/tissues
what is atrophy?
decrease in size of a tissue/organ due to a decrease in cell size (degradation pathways) or cell number (apoptosis)
A decrease in cell size can be accomplished by which degradation pathways?
ubiquitin-proteasome pathway, autophagy (microautophagy, macroautophagy, chaperone-mediated auotphagy)
contrast the ubiquitin-proteasome pathway and the autophagy pathway?
UP: requires ATP, specific, mostly degrades short-lived/damaged proteins (gene expression, differentiation), and cytoskeleton (IF) A: activated by cell stress. degrades proteins and organelles. can be selective or non-selective.
what is metaplasia
an alteration in cell type as a result of a chang ein environment/stress
which disease is “high yield” for metaplasia. cause?
Barrett’s esophagus. cells in esophagus change from stratified squamous epithelium to simple columnar mucus producing epithelium to better cope with reflux of stomach acid into esophagus
what is dysplasia
disordered cell growth; can progress to cancer if stimulus persists
In general, epithelial cells that are located closer to BM proliferate/differentiate and cells that are more apical (towards lumen) proliferate/differentiate
closer to BM=proliferate closer to lumen=differentiate, even lose their nucleus!
what is the morphologic hallmark of cell death? how can this occur (3)
loss of nucleus that occurs via nuclear condensation, nuclear fragmentation, nuclear dissolution
pyknosis AKA
nuclear condensation (small dark nucleus)
karyorrhexis AKA
nuclear fragmentation