Disorders of Growth and Neoplasia Flashcards
What does congenital mean?
Present from birth
What does agenesis mean?
Complete failure to develop
What does aplasia mean?
Failure to grow ie. Tissue or organ is present but it is small and rudimentary
Are hypoplasia and aplasia different?
No, they can be used interchangeably
What does dysplasia mean?
Abnormal development, resulting in disorganised cells and architectural distortion
What does atresia mean?
Closure of a normal opening
What is a common example of atresia in pigs?
Atresia ani
What are four different types of adaptations cells may undergo when subject to stress?
- Atrophy
- Hypertrophy
- Hyperplasia
- Metaplasia
What does atrophy mean?
Cell shrinking after normal growth has been reached.
What three events take place inside a cell undergoing atrophy?
- Decreased protein synthesis
- Increased protein catabolism
- Increased autophagy
What are five microscopic features of an atrophied organ?
- Decreased cell size
- Prominent vessels and connective tissue
- Crowding of small cells
- Fatty infiltration
- Lipofuscin accumulation
What mechanism to atrophied cells use to return to their normal size?
Hypertrophy, as long as the stimulus is removed.
What causes serous atrophy to occur?
Rapid mobilisation of fat stores
Where is the last reserve of fat stores?
In the bone marrow
What is progressive atrophic rhinitis?
A Pasteurella multocida infection in pigs causing:
- Atrophy of nasal mucous secreting glands
- Reabsorption of nasal turbinate bones
- Proliferation of fibroblast and associated collagen deposition
What is abiotrophy?
Genetically programmed premature or accelerated degeneration of cells.
What are some examples of abiotrophy?
- Cerebellar abiotrophy in lambs
2. Retinal photoreceptor dysplasia syndrome in dogs
What are some factors which contribute to ageing of organisms?
- Replicative senescence due to telomere caps shortening
- Accumulation of cellular injuries, such as free radical damage to organelles
- Decreased capacity for endogenous DNA repair enzymes to recognise and repair damaged DNA segments
What are the two adaptive cell processes which increase tissue mass?
- Hypertrophy
2. Hyperplasia
What does hypertrophy involve?
Increasing cell size
What does hyperplasia involve?
Increasing cell number
What cell types are able to undergo hyperplasia?
Liable and stable cells
What is the difference between hyperplasia and neoplasia?
Hyperplasia is a reversible and controlled process, neoplasia is not
In which organs is nodular hyperplasia a common finding in domestic animals?
Pancreas and liver
What does metaplasia involve?
Transformation of fully a differentiated, mature cell type to another mature cell type.
What is meant by glandular metaplasia?
Transformation of epithelial cells into mucous-secreting cells