Inflammation

Get a hint

What is hyperplasia?

Click the card to flip 👆

Increase in number of cells in organ or tissue.
Cells that are capable of mitotic division.
Physiologic
- Hormonal (e.g. breast enlargement)
- Compensatory (e.g. liver hyperplasia after partial removal)
Important response in wound healing (proliferating fibroblasts and blood vessels contribute)
Non-physiologic
- excessive hormonal stimulation or effects of growth factors on target tissues. e.g. skin warts due to growth factors produced by certain viruses.

Click the card to flip 👆

1 / 21

Terms in this set (21)

What is hyperplasia?

What is metaplasia?

Reversible change in which one adult cell type is replaced by another.
Thought to involve reprogramming of undifferentiated stem cells.
Often occurs in chronic irritation and inflammation.

What is dysplasia

Deranged cell growth of a specific tissue that results in cells that vary in size, shape, and organization. Associated with chronic irritation and inflammation.
Strong indicator for cancer.

Hypoxic cell injury

Deprives the cell of oxygen and interrupts oxidative metabolism and the generation of ATP.
Stimulates red blood cell formation and angiogenesis.
Can be a result of decreased oxygen amount in air, ischemia, respiratory disease, decreased BF, edema, anemia, inability of the cells to use oxygen.
- Ischemia: impaired oxygen delivery and impaired removal of metabolic end products (e.g. lactic acid).
- Edema: if the oxygen delivery is limited by distance

The cell reverts to anaerobic metabolism, using limited glycogen stores. pH falls due to lactic acid accumulation -> chromatin clumping and cell shrinkage.

Reduced ATP: failure of the energy dependent sodium/potassium ATPase -> water accumulation in the cell -> injury to lysosomal membranes -> lysosomal enzymes into the cytoplasm.

Apoptosis

Highly selective process that eliminates injured and aged cells.
1) Shrinking of the cell.
2) condensation of the nucleus and cytoplasm. Chromatin aggregates in nuclear envelope.
3) The cell becomes fragmented, but maintains integrity of the plasma membrane. Hence, does not initiate inflammation.
4) Macrophages engulf the fragments.