Pathoma 1. Growth Adaptations Flashcards
What are the 2 permanent tissues that only undergo Hypertrophy (no hyperplasia)
Cardiac Myocytes, Skeletal muscle, Nerve
Pathologic hyperplasia can lead to dysplasia and cancer. Give 1 example and 1 exception
Endometrial hyperplasia leads do Ca.
BPH (Benign Prostatic hyperplasia) does not)
How can atrophy decrease cell size?
Ubiquitin Proteosome degradation of cytoskeleton
and
Autophagy of cell components (thru lysosome)
What is the change of epithelium in Barrett’s Esophagous?
Squamous to Columnar
Metaplasia is reversible, but can progress to dysplasia and Ca. Cite example and exception
Barrett’s Esophagus progresses
Apocrine Metaplasia in breast is still reversible
What’s the mechanism of metaplasia?
Reprogramming of stem cells
Name the metaplasia that results from Vit.A deficiency, and other conseq of this deficiency
Keratomalacia (bc there’s an inability to maintain conjunctiva specialized tissue)
Acute Promyelocytic leukemia (due to 15-17 translocation)
Nightblindness
What is a common mesenchymal tissue metaplasia?
Myositis ossificans (bone grows in muscle due to trauma
WHat is dysplasia?
Disorded cellular growth. ALways the pre-step of Cancer (arises after longstanding pathologic hyperplasia or metaplasia)
Ex: CIN 1, 2, 3
What is Aplasia? + example
failure of cell production during embryogenesis Ex. Unilateral renal agenesis
Describe Hypoplasia and example
decrease in cell production during embryogenesis. Ex: streak ovary in Turner’s Sme
What is hypoxia and the 3 mains causes:
Decreased O1 flow to tissues.
- Ischemia
- Hypoxemia
- Decreased O2 carrying capacity of blood
What are the 3 mais causes of ischemia?
- Atherosclerosis,
- Vein Blockage (budd chiari sme= thrombossis of hepatic vein, due to 1. Policytemia Vera or Lupus hypercoagulable state)
- Shock
What is Hypoxemia and Examples?
Low Partial pressure of O2 in Blood (PaO2<60mmHg, and SaO2<90%)
Main causes: LOW FiO2 (P of O2 in the atm)-due to High Altitude LOW PAO2(bc of high PACO2, when there's hypoventilation, COPD and intersticial fibrosis of lungs
All leads to hypoxemia and then to hypoxia
3rd cause of Hypoxia is: and give examples
Decreased O2-carrying capacity of blood
- Anemia (hemoglobin LOSS)= SaO2 stays normal.
- CO Poisoning (Hb DYSFUNCTION)= SaO2 is decreased bc O2 is displaced.
- Methemoglobinemia: iron in Heme is oxidized from Fe2+ to Fe3+, and doesn’t bind O2 anymore. LOW SaO2.
Describe etiology of CO poisoning and features
smoke from fires, exhaust, gas heaters.
Headache and cherry red appearance of skin….coma nad death
WHat’s the etiology of Methemoglobinemia? and features
Oxidant stresses (sulfa/nitrate drugs) or newborns
Cyanosis + chocolate colored blood
TTM: IV methylene blue helps reduce Fe back to 2+
Hypoxia impairs oxydative phosphorylation. WHat are the consequences of this.
- low ATP.= impaired Na/K Pump=Swelling. IMpaired Ca2+ pump and it stays in cell, activating enzymes. Impaired AEROBIC glycolysis
What is the hallmark of cell injury while it’s still reversible?
SWELLING. Leads to loss of microvilli, membrane blebbing.
What’s the hallmark of irreversible damage? and the consequences:
Membrane Damage.
- Find Ez in blood (Troponins, CPK)
- Damage to mitochondrial membrane (Citocrome C leaks and causes APOPTOSIS.