Pathology

Question 1

Mechanism of dystrophic calcification

Answer 1

1. Ca2+ binds phospholipid membrane.
2. Phosphates in membranes bind Ca2+
3. Deposits form
4. Structural changes form which promote the formation and deposition of more crystals

Question 2

4 main causes of hypercalcemia:

Answer 2

1) increased PTH secretion
2) Destruction of bone tissue (Bone cancer, breast cancer, Paget’s disease)
3) Vitamin-D related disorder
4) Renal Failure

Question 3

A form of necrosis:
- An architecture of dead tissues is preserved for a span of at least some days ( Fig. 1-11 ).
- firm texture.
- The injury denatures not only structural proteins but also enzymes and so blocks the proteolysis of the dead cells; as a result, eosinophilic, anucleate cells may persist for days or weeks.
- Ultimately the necrotic cells are removed by phagocytosis of the cellular debris by infiltrating leukocytes and by digestion of the dead cells by the action of lysosomal enzymes of the leukocytes. Ischemia caused by obstruction in a vessel may lead to _______________ of the supplied tissue in all organs except the brain. A localized area of
_____________ is called an infarct.

Answer 3

Coagulative necrosis

Question 4

A form of necrosis is characterized by digestion of
the dead cells:

• transformation of the tissue into a liquid viscous mass.
• bacterial or, occasionally, fungal infections, because microbes stimulate the
  accumulation of leukocytes and the liberation of enzymes from these cells.
• Creamy yellow because of the presence of dead leukocytes and is called pus. For unknown reasons, hypoxic death of cells within the central nervous system often manifests as_________________.

Answer 4

Liquifactive necrosis

Question 5

_______________ is not a specific pattern of cell death, but the term is commonly used
in clinical practice.

Seen in lower limb that has lost its blood
supply and has undergone necrosis (typically coagulative necrosis) involving multiple tissue
planes. When bacterial infection is superimposed there is more liquefactive necrosis because
of the actions of degradative enzymes in the bacteria and the attracted leukocytes (giving rise
to so-called wet gangrene).

Answer 5

Gangrenous necrosis