Lecture 1 - Introduction To Pathology Flashcards
What is pathology?
Branch of medicine concerned with understanding the process of disease
What is a disease?
A pathological condition of a body part, an organ or a system characterised by an identifiable group or signs or symptoms
In a disease, how is homeostasis affected?
Homeostasis fails
What is chemical pathology?
Biochemical investigations of disease
What is Haematology?
Diseases of the blood
What is Immunology?
Diseases of the immune system
What is medical microbiology?
Disease-causing microbes including advice on antibiotic usage
What is cellular pathology?
Examines organs, tissues and cells for diagnosis and to guide treatment
Why is microscopic diagnosis important?
Gives a definitive diagnosis
What is the difference between Histology and Cytology?
Histology = Looking at pieces of tissues
Cytology = Individual/ a very small number of cells are aspirated
What does aspirated mean?
Drawn from the body by suction
What is histology good for?
Immunohistochemical and molecular testing
Can differentiate invasive from in situ disease
What are some key notes about cytology?
Faster and cheaper than histology
Higher inadequate and error rates
Can be used for cells in fluids
What is an Adnexal mass?
A lump in the tissue near the uterus
What is ascites
Fluid accumulation in the abdominal cavity
What information can be determined from Histopathology/cytology?
Inflammatory or neoplastic
Benign/malignant
Primary Tumor or metastasis
Grade of cancer
How is immunohistochemistry and molecular pathology useful for treatment?
Can determine the likely efficacy of further treatments
What is autolysis?
Cell degradation (when the blood supply is cut off cell digests itself)
What are the steps in producing slides for microscopy?
Sample sliced thinly
Fixation
Embedding
Blocking
Microtomy
Staining
Mounting
What is fixation?
Specimen suspended in formalin solution
What does fixing actually do?
It prevents the specimen undergoing autolysis by inactivating tissue enzymes and denaturing protiens.
Also hardens the tissue
What is done when embedding a specimen?
Paraffin wax surrounds the specimen
Then dehydration with alcohol
Alcohol removed and XYLENE added
More wax added
What is blocking?
Sample put into metal trays and more wax added
Metal tray is then removed
What is microtomy?
Machine called microtome very thinly slices the specimen into sections
What stains are commonly used?
Haematoxylin and eosin (H&E)
What does Haematoxylin stain and what colour does it stain?
Stains Nuclei purple
What does Eosin stain and what colour does it stain?
Stains Cytoplasm and connective tissue pink
What is mounting?
Preserving and protecting the slice of tissue
Mounting medium is add, dries and hardens, coverslip then gets attached
What is good about frozen sections and when are they used?
They are produced very quickly so are made in surgery and used to make Intra operative decisions
What is the downside to frozen sections?
Less clear than formalin fixed
Don’t last very long
What is immunohistochemistry and what is its use?
Antibody made that has an enzyme which catalyses a colour producing reaction
Antibody can be made specific to pretty much any antigen
What is molecular pathology?
Studies how diseases are caused by alterations in normal cellular molecular biology (changed DNA, RNA or proteins)
