Growth Disorders Flashcards
What does agenesis mean?
An organ does not develop at all (genetic defect)
- Pretty rare - on occasion person might be born with no salivary glands at all
What does aplasia mean?
An organ fails to develop normal structure from primitive embryonic structure
- Tissues present but don’t get development of normal structure
What does hypoplasia mean?
Less tissue formed than normal structure
- Tissue is there but amount formed is much less than it normally should be
What does hamartoma mean?
- Normal tissue but size and structure much greater than normally would be
- Tumour-like growth
- Only grows in patient’s growth period, but excessive - will stop at a certain age
What are examples of hamartomas?
- Pigmented naevi (moles)
- Haemangioma - arises in blood vessels
- Lymphangioma - arises in lymphatic tissues
What does a haemangioma look like under a microscope?
- Does not have a fibrous tissue capsule - a benign tumour does
What types of lymphangioma are there?
- Most are cavernous
- Tongue
- Cystic hygroma
What is a naevus?
A mole
What does ‘ectopia’ mean?
Normal tissue in an abnormal site
What is an example of ectopia (normal tissue in an abnormal place)?
Mickel’s diverticulum - an outpouching of the small intestine. Can contain gastric type mucosa (should not have this in the small intestine)
What is meant by ‘atrophy’?
When cells become smaller than normal - decrease in size or number of cells
What is meant by ‘hypertrophy’?
Much larger cell than normally would be
What is meant by ‘hyperplasia’?
Many more cells than should be but same size
What is meant by ‘metaplasia’?
Change of tissue from one type to another type as long as it is the same group - epithelial tissue cannot change into connective tissue
What is meant by ‘dysplasia’?
Abnormal change in cells which makes them become more susceptible to become malignant
