Pathology - lecture notes+Robins

Pathology - lecture notes+Robins Types of CT modulations (4) - ANS-1. Fibrillar - transparent and non-transparent 2. Myxoid - amorphous, gelatinous, high presence of proteoglycans and hyaluronic acid 3. Elastic 4. Hyalin - loss of fibrous appearance, higher degree proteoglycans, different from hyalin cartilage microscopically What type of CT modulation is present in keloids? - ANS-Hyalin Myxoid CT modulation - ANS-Higher presence of hyaluronic acid and proteoglycans, and lower presence of fibrous components, makes the tissue more gelatinous. It can appear in the skin, placental villi and in ganglia. Mechanisms of cell injury in oxidative phosphorylation disorders (6) - ANS-1. ATP depletion 2. Increase in ROS 3. Increased Ca2+ uptake by mitochondria due to decreased mitochondrial membrane potential 4. Redox imbalance 5. Inhibition of beta-oxidation of FAs 6. Release of cytochrome C through mitochondrial permeability transition pores -> caspase initiated apoptosis How is cell damage initiated by increased intracellular calcium? - ANS-Ca2+ activates phospholipases, proteases, endonucleases and ATPases that break down membrane phospholipids, structural proteins, DNA and ATP respectively. Depletion of extracellular Ca2+ delays cell death after exposure to hypoxia and toxins. Types of clones (cellular) - ANS-1. Reactive single clone (stem cell independent) - arise from differentiated cell capable of mitotic expansion 2. Constitutional, regenerative clone (stem cell dependent) What cell lines arise from mesenchymal stem cells? (5 main) - ANS-1. Osteoblasts/cytes 2. Chondroblasts/cytes 3. Myoblasts/cytes 4. Fibroblasts 5. Adipoblasts/cytes "Tissues in adults are composed of clones of... - ANS-...adult permanent type" (???) Symptoms that are typically seen together in protein trafficking disorders (5) - ANS-1. Decreased pigmentation (melanosome impairment) 2. Altered hemostasis (platelets) 3. Lysosomal dysfunction (impaired macrophages) 4. Immunodeficiency (impaired macrophages and other WBCs) 5. Neurologic disorder (synaptic vesicles) Examples of quantitative variation within a clone (2) - ANS-hyperplasia and atrophy What is the difference between metaplasia and dysplasia? - ANS-Metaplasia is reversible and occur when a cell is exposed to an environment is not originally fit to handle (eg. Barret esophagus where epithelium change from squamous to columnar). Dysplasia is irreversible and more pathological