What is cancer? Flashcards
What is metaplasia?
A change from one mature cell type to another in response to a stimulus
What type of stimulus is the usual cause of metaplasia?
Noxious substances
How does smoking cause metaplasia?
Smoking causes thermal and toxic injury to the epithelium of the lungs
This causes metaplasia of the epithelium to squamous epithelium which is much more resistant to heat and trauma
What is the cause of Barrett’s oesophagus?
Gastric juices burn easily through squamous epithelium in the oesophagus
This causes metaplasia of squamous epithelium into glandular epithelium which releases alkaline mucin
What can constant metaplastic signals cause?
The cells eventually begins to ignore the signals and undergo metaplasia autonomously, even if the stimulus is stopped
What is dysplasia?
The abnormal development of cells
What are dysplastic lesions?
Lesions caused by the many mutation of cells, however is not yet malignant. It cannot yet invade tissue
What is pleomorphism?
The presence of many different shapes and sizes of cells
What is meant by a high nucleus:cytoplasm ratio?
A very large nucleus and little cytoplasm
What is hyperchromasia?
Different colours after staining
What is neoplasia?
New growth (Abnormal mass but unknown malignant potential)
What are the main categories of carcinogens?
Inherited predisposition
Chemicals
Radiation
Infection
Inflammation
Lifestyle factors
Bad luck
What is carcinogenesis?
The development of cancer
What syndrome is caused by mutation of p53?
Li Fraumeni syndrome
Which cancer’s risk is increased by a mutation of the BRCA gene?
Breast and ovarian cancer
What test is used to define chemical carcinogens?
The Ame’s test in which cells are introduced to the stimulus to see if it causes mutation