Growth Adaptations, Cell Injury, Cell Death Flashcards
Basic Mechanism of Hypertrophy
Gene activation, protein synthesis, production of organelles
The uterus during pregnancy undergoes what process(es)?
Hypertrophy and hyperplasia…These two things usually occur together
Can permanent tissues make new cells?
No
What are the three major permanant tissues in the human body>
Nerve, skeletal muscle, cardiac muscle
The permanant tissues undergo——— only?
Hypertrophy
A decrease in cell umber occurs via
apoptosis
A decrease in the size of cells occurs via
ubiquitin-proteasome degradation of the cytoskeleton and autophagy of cellular components
How does the ubiquitin-proteasome degradation mechanism work?
Intermediate fibers of the cytoskeleton are tagged with ubiquitin and destroyed by proteasomes. Autophagic vacuoles then collect cell components and fuse with lysosomes which break down the cell components
Metaplasia stimulated by?
Change in stress on an organ
Metaplasia most commonly involves what cell types?
Surface epithelium
Three types of epithelium
squamous, columnar, transitional
Barrett Esophagus
due to gastric reflux, nonkeratinizing squamous epithelium turns into mucin producing non-ciliated columnar epithelium. May progress to adenocarcinoma of the esophagus if untreated.
How does metaplasia actually occur
re-programming of stem cells
What is the one type of metaplasia that will most likely not lead to cancer
Apocrine metaplasia (seen with fibrocystic change in breast tissue)
Significance of vitamine A deficiency
Can result in metaplasia. Vitamin A is responsible for differentiation of epithelial cells and maturation of the immune system
Keratomalacia
develops due to vitamin A deficiency. The thin squamous lining of the conjunctiva undergoes metaplasia into a keratinizing squamous epithelia.
Metaplasia can also occur within mesenchymal tissues, an example is
myositis ossificans…muscle changes to bone during healing after trauma
Dysplasia
disordered cell growth
Dysplasia is reversible
true
Aplasia
failure of cell production during embryogenesis
Hypoplasia
Decrease in cell production during embryogenesis
Are neurons highly susceptible to ischemic injury
Yes.
Why is hypoxia a problem
Oxygen is the final electron acceptor in the electron transport chain so low oxygen means the ETC doesn’t work and you don’t make ATP. If you dont make ATP, three main things go wrong: Na K pumps dont work so Na is retained inside cells along with water (swelling), Calcium pumps dont work, and anaerobic glycolysis starts up.
Ischemia is
Decreased blood flow THROUGH an organ associated with decreased arterial perfusion (atherosclerosis), decreased veinous drainage, shock
