Mechanisms of Disease Flashcards
Define apoptosis
Programmed cell death by intracellular programmes (degradation of DNA/proteins)
Apart from TB name three other granulomatous infections.
-Leprosy -Cat-scratch disease -Syphilis -Chronic fungal infections -Xanthogranulomatous pyelonephritis
Define aplasia
Complete failure of a specific tissue or organ to develop
Define arteriosclerosis
The thickening of the walls of arteries and arterioles, usually as a result of hypertension or diabetes mellitus
Define atheroma
The accumulation of intracellular and extracellular lipid in the intima and media of large and medium sized arteries
Define atherosclerosis
The thickening and hardening of arterial walls as a consequence of atheroma
Define disease.
The consequence of failed homeostasis with consequent morphological and function disturbances
Define chronic inflammation.
Chronic response to injury with associated fibrosis
Define atrophy
Shrinkage of a tissue or organ due to an acquired decrease in size and/or number of cells
Define dysplasia
Abnormal maturation of cells within a tissue
Define hyperplasia
Increase in tissue or organ size due to increased cell numbers.
Define hypertrophy
Increase in tissue or organ size due to increased cell size.
Define hypoplasia
Incomplete development of a tissue or organ
Define metaplasia
Reversible change of one DIFFERENTIATED cell type to another.
Define necrosis
Changes after cell death in living tissue
Describe the appearance of caseous necrosis
It looks like cheese - contains an amorphous (structureless) debris
Define regeneration.
The replacement of dead or damaged cells by functional, differentiated cells
Describe the appearance of an arterial thrombi?
Pale, granular, low cell count and lines of Zahn
Describe the appearance of a venous thrombi?
Deep red, soft, gelatinous and a high cell count
Describe the basic structure of the collagen molecule
-Glycine every third position -3 alpha chains -Left handed triple helix -Mostly hydroxyproline and proline residues in other positions
Describe the differences in the appearance of benign and malignant tumour to the naked eye.
-Benign - grow in a confined local area and so have a pushing outer margin -Malignant - irregular outer margin and shape and may show areas of necrosis and ulceration
Describe the features of coagulative necrosis
-Histologically the structure is preserved creating “ghost outlines” -After this the tissue goes through acute inflammation and there is a mass immigration of phagocytes and neutrophil polymorphs -Increased eosinophilia of cytoplasm
Describe the features of liquefactive necrosis
-Liquefaction of tissues -Massive neutrophil immigration
Describe the four steps of infiltration of neutrophils.
- Margination - neutrophils line up at the edge of blood vessels along the endothelium 2. Rolling - neutrophils roll and begin to stick 3. Adhesion - fully stick 4. Emigration