Week 2: Cell death and adaptation workshop Flashcards
What are the features in reversible cell injury?
Cellular swelling - small clear vacuoles may appear within the cytoplasm due to degeneration of the ER, more eosinophilic cytoplasm
Cell membrane changes- blebbing or loss of microvilli
Fat accumulation -typically in the liver
Mictochondrial swelling
Nuclear alterations - clumping of chromatin
What are the key morpholigical features of necrosis?
Darker staining cytoplasm
Vacuolated /moth eaten cytoplasm after enzymes have digested the cellular content
Discontinous plasma membrane
Calcium precipitates
Nucleus may shrink and darken or fragment or lighten
What are the cellular features of necrosis?
Swelling
Nucleus - pyknosis (condense), karyorrhexis (fragments), karyolysis (fades)
Plasma membrane is disrupted
Cellular contents, undergoes enzymatic digestion may leaks out of cell
What are the cellular features of apoptosis?
Shrinkage
Nucleus fragments
Plasma membrane is intact but has an altered structure
Cellular content is intact and released within apoptopic bodies
What are the signs of early ischemic damage in an MI?
(still reversible)
Cell nucleus is still present
Cells are lighter staining - reduction in sarcomeres
Patchy appearance
Cell swelling
What are the signs of coagulative necrosis in cardiacmyocytes in MI?
Lack of nucleus
Darker staining cytoplasm
No cellular content is visible
Define myocardial infarction
Death of cardiac muscle due to severe prolonged ischemic conditions
What are the primary diagnostic tests for MI?
ECG
Followed by serum cardiac enzymes
What are the normal serum cardiac enzymes that are tested for in a suspected MI?
What is their normal value?
Troponin 1 <0.03ng/mL
Troponin T <0.1ng/L
Creatine kinase MB isoenzyme <10mg/mL
When and what gross changes occur after an MI?
Visible ater 12hrs
Dark Mottling develops to a yellow core eventually becoming a scar
What is the time span of histological changes in MI?
take 6 to 12 hours to develop
- coagulative necrosis
- neutrophil influx after 12 to 24 hours
- loss of nuclei on day 1 to 3
-phagocytosis on day 3 to 7
- scar forms in 2 months
What is the primary goal in an MI patient?
Manage as soon as possible
What is the cause of cell injury in an MI?
Coronary artery occlusion leading to severe hypoxia and prolonged ischemic conditions for group of cardiac myocytes
Leads to inhibition of myocardial contractility - causing MI
Eventually tissue dies
Why is troponin T the most valued serum cardiac enzyme?
When cardiac myocytes are damaged is released through porous cell membrane
Is the most specific and sensitive for MI.
Can be detected after 2 hours
Is proportional to the degree of damage
What are the potential complications of acute MI?
Arrhythmias
Hypotension
Ventricular septal rupture
Left ventricular free wall rupture
Left ventricular aneurysm formation