Patho Final Lec 3

Question 1

What are the biochemical mechanisms and sites of damage in cell injury?

Answer 1

Hypoxia and ischemia: leads to necrosis due to energy deficit
Injurious stimuli: increase ROS, causing damage to lipids, proteins, and nucleic acids (cell necrosis)
Mutations and cell infection: accumulation of misfolded proteins leads to apoptosis.
Radiation: DNA damage leading to apoptosis.
Infections and immune disorders: inflammation releases toxic molecules causing necrosis or apoptosis

Question 2

What happens when ischemia or hypoxia occur?

Answer 2

Defective oxidative phosphorylation, so low ATP.
Failure of energy dependent pathways.
Anaerobic glycolysis occurs.
Different cells have different resiliencies towards hypoxia.
Damage to mitochondrial and lysosomal membranes.
Causing necrosis or apoptosis.

Question 3

What are some pathways disrupted by hypoxia?

Answer 3

No ATP for Na-K pump, resulting in swelling.
Lactic acid oxidation stops, decreasing pH and inactivating proteins.
Disruption of protein sysnthesis (ribosomes dont work).
ROS accumulation (no breakdown)