Cell Death Flashcards
(16 cards)
What are the 2 type of signs of early reversible cellular injury?
Biochemical
Morphological
What are the biochemical early reversible cellular injury signs?
Change in the intracellular levels of ATP
Membrane channel pumps are disrupted
What are the morphological early reversible cellular injury signs?
Hydropic change (Cellular swelling)
Fatty Change
What are the morphological signs of later irreversible cellular injury?
Nuclear changes - Can tell us whether the cells have died or not
Cytoplasmic changes - Can tell us how the cells have died/ what has lead to the death of cells
What are the nuclear changes which indicate cell death?
Karyolysis
Pyknosis
Karyorrhexis
Nuclear dissolution
Anuclear necrotic cell
What is Karyolysis?
Nuclear fading - chromatin dissolution due to action of DNAases and RNAases (enzymes).
What is Pyknosis?
Nuclear shrinkage - DNA condenses into shrunken basophilic mass
What is Karyorrhexis?
Nuclear fragmentation - Pyknotic nuclei membrane ruptures and nucleus undergoes fragmentation
What is Nuclear dissolution?
If the cell goes through all 3 nuclear changes, then the cell loses its nucleus which is known as nuclear dissolution, so you’re eventually left with an Anuclear cell.
What are the cytoplasmic changes which indicate cell death?
Hypereosinophillia
Vacuole formations
What is Hypereosinophillia?
Normal cells usually have a basophilic cytoplasm, which stain pale blue when stained with hemotoxin or eosin
As cellular injury/damage progresses, and there are irreversible changes, there is a significant change in pH
This is due to the break down of proteins. As the pH changes, certain proteins start to drop out of solution and you get coagulation taking place
This leads to increase uptake of eosin as a stain and you start to get Hypereosinophillia
What are vacuole formations?
Vacuoles start to form in different cellular compartments including the organelles.
This may be linked to the entry of water
Which is related to the failure of membrane pumps
Vacuoles are only seen a certain type of cell death known as necrosis
They are not seen in apoptosis
What are the different pathways of cell death?
Necrosis
Apoptosis
Necroptosis
What is Necrosis?
Very common/ most common pathway in cell injury
Necrosis is always pathological
For example from toxicity/ Ischemia/ Trauma etc
Always affects multiple cells
What is Apoptosis?
Tightly regulated process
Very often works in a physiological way
For example, embryogenesis, withdrawal of hormones or changes linked to inflammation or infection
It is regulated by enzymes known as caspases (cysteine-aspartic proteases)
Apoptosis can become corrupted/ dysfunctional in a number of diseases like cancer
What is necroptosis?
Hybrid process of necrosis and apoptosis
It is thought to be linked in particular to inflammatory diseases
