1.2 Cellular Injury Flashcards
When does injury occur?
Injury occurs when stress exceeds the cell’s ability to adapt
What is hypoxemia?
It is a low PaO2 (arterial)
What are the causes of hypoxemia?
It can be due to low FiO2 or a low PAO2 (alveolar)
An increased PACO2 will also cause it indirectly by lowering PaO2.
What form of iron binds oxygen
Fe2+
Fe2 binds O2
What does hypoxia impair?
Oxidative phosphorylation
What is the hallmark of cell injury?
Swelling
How does hypoxia lead to swelling?
It causes a shutdown of oxidative phosphorylation which leads to decreased ATP synthesis, leading to the shutdown of the Na/K pump.
This causes a buildup of Na in the cell and causes H2O to enter and leads to swelling.
What are some of the consequences of cell swelling?
- Loss of microvilli
- Membrane Blebbing
- Freeing of more ribosomes
What are the consequences of membrane damage?
- Intracellular proteins leak out
- Ca2+ rushes into the cell
Where is the electron transport chain?
Inner mitochondrial membrane
Why is damage of the mitochondrial membrane so bad?
It can leak out cytochrome C which can trigger apoptosis of the cell
