S1 L1 Flashcards
What is pathology?
Study of suffering
What is medical microbiology?
The study of microorganisms such as bacteria, viruses, fungi, and parasites. It aims to understand their role in disease and symptom presentation.
What is chemical pathology?
Biochemical investigations of disease =combines clinical skills with laboratory work. Chemical pathologists use biochemical tests to diagnose disease and to manage patients
Describe the haematology pathology discipline
study and treatment of diseases of the blood.
Describe the immunology pathology discipline
This branch of pathology is concerned with the immune process of the body.
Describe the Histopathology and cytopathology pathology discipline
Histopathology is the study of the cellular changes within tissues that are caused by disease. Cytopathology is a diagnostic technique that examines sampled cells from various body sites to determine the cause or the nature of disease. e.g. pap smear test
Describe the histology technique for obtaining samples for diagnostic microscopy
Histology will involve the removal of a tissue sample to be able to assess both tissue and cell morphology.
examples: core biopsies, cancer resection specimens
Describe the cytology technique for obtaining samples for diagnostic microscopy
Cytology involves taking samples of free cells separate from the structure of the tissue often obtained by fine-needle aspiration.
Cytology is cheaper, faster, and less invasive than a histological sample, however also has higher rates of error.
It be used before histology as a preliminary test.
what questions does a histopathologist ask to arrive at a diagnosis?
Is the sample normal or abnormal?
Is it inflammatory or neoplastic?
Is it benign or malignant?
Is it a primary tumour or a metastasis?
What can a histopathologist tell us about a diagnosis of cancer?
type of cancer grade of cancer stage of cancer completeness of excision and if margins are involved which ones likely efficacy of further treatments
What happens in fixation?
The preservation of biological tissues from decay due to autolysis or putrefaction.
Usually formalin (formaldehyde in water) is used, and the process can take up to 48 hours.
What happens in the cut-up section of producing a histological report?
The tissues are cut up and placed into a cassette and then placed in racks of formalin (a solution containing formaldehyde which fixes cells by cross-linking proteins).
describe the process of embedding
samples are dehydrated using alcohol in a vacuum to dehydrate the cells. The alcohol is then replaced with xylene (which can mix with wax). The xylene is finally replaced with molten paraffin wax, which will permeate the cells to fix them.
describe the process of blocking
The embedded tissues are removed from their cassettes and put into metal blocks, which are then filled with more molten paraffin wax.
The wax is allowed to cool and the metal tray is moved. The tissues are now embedded in blocks of wax and are hard enough to be cut
describe the process of microtomy
The blocks are cut into very thin sections using a machine called a microtome. The sections are 3-4 microns thick, which is thin enough to be seen through with a light microscope.
