General Principles of Cell Growth, Injury, & Death Flashcards
Generally, pathologic hyperplasia can progress to dysplasia and eventually cancer - what is the major example where this does not apply?
- benign prostatic hyperplasia (BPH); the hyperplasia here is not associated with an increased risk of cancer
How does atrophy occur (3 main mechanisms)?
- apoptosis, autophagy, and degradation of the cytoskeleton (via ubiquitin-proteosomes)
Acid reflux can cause the esophagus’ normal _______ cells to change into ______ cells (which are seen in the stomach); this metaplasia is known as:
- change from squamous cells to columnar cells (columnar cells can better handle the acidic environment)
- called Barrett’s esophagus
Myosititis Ossificans
- metaplasia in inflamed skeletal muscle
- bony growth is produced in the muscle during healing
Dysplasia
- disorganized cellular growth
- the proliferation of precancerous cells
T or F: Dysplasia, like cancer, is irreversible.
- false!
- dysplasia is reversible, but once it progresses to carcinoma it is irreversible
Slow and constant stress will result in ______; Rapid and strong stress will result in ______.
- slow and constant = atrophy
- rapid and strong = infarction
What is Hypoxia? What are the three main causes?
- hypoxia = low O2 delivery to tissues
- ischemia, hypoxemia, and decreased O2 carrying capacity of the blood are the three main causes
Methemoglobinemia
- when the Fe2+ in Hb becomes Fe3+ (methemoglobin), resulting in the inability of Hb to bind O2
- gives blood a chocolate-colored tinge
Ischemia can also occur through blockage of the vein, decreasing the flow of fresh blood to the organ. This can occur in the liver in what is known as:
- Bud Kiari Syndrome
- (thrombosis of the hepatic portal vein)
Without O2, what three major events occur in the cell?
- cellular swelling, inappropriate activation of enzymes, and lactic acidosis
Why does cellular swelling occur in hypoxia?
- O2 is needed to form ATP, which is necessary to maintain the Na+-K+-ATPase pump. when this fails, Na+ will accumulate in the cell and will bring in a ton of water with it = swelling
What is the hallmark sign of reversible injury?
- cellular swelling
Why does the inappropriate activation of enzymes occur in hypoxia?
- O2 is needed to form ATP, which is necessary for maintaining low [Ca2+] (a potent enzyme activator) in the cytosol. without ATP, Ca2+ builds up in the cytosol and can freely activate enzymes
What is the hallmark of irreversible injury?
- membrane damage
What is the hallmark of cell death?
- loss of the nucleus
What three events occur in the loss of a nucleus?
- pyknosis –> karyorrhexis –> karyolysis
Pyknosis
- 1st step in loss of nucleus
- the nucleus shrinks