Chapter 2 (Sections 3-5) - Cell Responses Flashcards
What are the 3 principal cell targets of injurious stimuli?
Mitochondria
Cell Membrane
DNA
What are some causes of Mitochondrial damage that causes necrosis?
Hypoxia
Toxins
If the Mitochondria is targeted by hypoxia and toxins, what will result?
DECREASED ATP production
INCREASED ROS
= Necrosis
What are some causes of Mitochondrial damage that cause apoptosis?
Protein and DNA damage
If the Mitochondria is targeted by protein and DNA damage, what will result?
INCREASED PRO-apoptotic molecules (BAK, BAX)
– Leakage of Cytochrome C out of Mitochondria
= Apoptosis
What are some causes of cell membrane damage?
ROS
Which cell membranes are targets of ROS?
Lysosomal
Mitochondrial
Plasma
If the Cell membranes are targeted by ROS, What will result?
Necrosis
What are some causes of DNA damage?
Radiation
Mutations
If DNA is damaged, what will result?
Apoptosis
Increased production of ROS or decreased scavenging of ROS leads to their excess. What is this called?
Oxidative stress
Oxidative stress can cause what damage to the cell?
Membrane damage
DNA damage and mutations
Protein modifications
What ion in excess in the cytoplasm can cause cell injury?
Calcium
Increased cytosolic calcium causes what damage to the cell?
Membrane damage
DECREASED ATP
Nuclear damage
Unfolded Protein Response
Accumulation of misfolded proteins in the ER can cause Apoptosis
What inflammatory cells can release large amounts of ROS that can damage the cell?
Neutrophils and Macrophages
What are the 4 cellular adaptations to stress?
- Hypertrophy
- Hyperplasia
- Atrophy
- Metaplasia
Hypertrophy
Increased cell SIZE!!
- Causes an increase in organ size too
Increase in cell size due to stress?
Hypertrophy
What is the mechanism of Hypertrophy
Increases Intracellular proteins to increase cell size
Most common cause of Pathologic Hypertrophy and an example
Increased workload
ex. Pressure overload on the heart
Most common cause of Physiologic Hypertrophy and an example
Hormone induced enlargement from hypertrophy of smooth muscle
ex. Increased uterine size due to estrogen during pregnancy
Hyperplasia
Increased cell NUMBER
Hyperplasia can only occur in cells that are capable of?
Cell division and thus replication