Pathology Flashcards
PA CXR
The x-rays through the back of the patient on to the film. Standard projection. Cardiac-thoracic ratio measured in this view.
AP CXR
The x-rays penetrate through the front of the patient on to the film. Heart size should not be measured on an AP film.
What is a congenital anomaly?
Anomalies that exist at or before birth regardless of the cause and congenital anomalies may be either functional/metabolic or structural.
Hypertrophy
Increase in size of cell and therefore increase in size of an organ. Enlargement is due to an increased synthesis of structural proteins and organelles. Occurs when cells are incapable of dividing, can be caused by increased functional demand or hormonal stimulation.
Hyperplasia
Increase in the number of cells in an organ or tissue. Adaptive response in cells capable of replication.
What can cause atrophy?
Loss of innervation, diminished blood supply, inadequate nutrition, decreased workload, loss of endocrine stimulation, age (senile atrophy).
What is neoplasia?
An abnormal tissue mass the growth of which is excessive (ie. not an adaptation to physiological demands) and uncoordinated compared to adjacent normal tissue. Neoplasm can be benign or malignant.
What is the importance of differentiation of a tumour?
1)Site of origin in metastatic disease
2)Prognosis-well differentiated often better than poorly differentiated.
3)Treatment
Well differentiated tumours resemble identifiable tissue types.
What is the stage of a tumour based on?
Size of the primary tumour, the extent of invasion into surrounding tissue, the spread to regional lymph nodes and presence or absence of metastases. TNM (tumour, nodes, metastasis) is used to stage tumours.
Define ‘anaplasia’
Lack of differentiation of a tumour (undifferentiated).
Define ‘dysplasia’
Disordered growth in which cells fail to differentiate fully, but are contained by the BM. Recognised by alterations in the appearance of cells- cell nuclei become hyperchromatic, nuclear membranes become irregular, nuclear to cytoplasmic ratio increase. Dysplasia may regress, persist or progress.
What is carcinoma in-situ?
Full thickness epithelial dysplasia extending from the basement membrane to the surface of the epithelium. There are no blood vessels or lymphatics within the epithelium above the basement membrane so the risk of metastasis is zero. This is why cervical/bowel screening is so important.
What ways can metastasis occur?
1) Lymphatic spread
2) Haematogenous spread
3) Seeding of body cavities- transcoelomic spread
