Flashcards in Intro, microscopes and autopsies Deck (21)
What is pathology?
Identifying disease, understanding processes of disease and attempts to explain symptoms and guide treatments
What are the two subtypes of cellular pathology?
Histology and cytology
What is the difference between histology and cytology?
Histology is tissue samples, cytology is usually fulids and aspirations (urine, effusions, breast and salivary gland aspirations)
What are the advs and disadvs of cytology?
- non or minimally invasive
- see cells in fluids
- preliminary test
- cant see tissue structutres
- can diagnose cancers ect but cannot give info on grading/ accutate diagnosis
Describe how a sample is prepared for viewing under a microscope
1. fixing- fixatives like formalin inactiveate tissue enzymes, denature proteins, prevent bacteria and harden tissue ready for cutting. This all prevents autolysis of cells.
2. hardening- remove water by gradually adding greater concentrations of alcohol then replace with xylene which will mix with molten paraffin wax
3. remove sample from cassette and put in metal box and then add molten paraffin wax, set hard then remove from tray
4. cut sections w/ microtome
5. float in water bath then pick up with microscope slide, H&E stain
6. mounting medium put on top then coverslip on top of this
What is immunohistochemistry? What colour does it stain?
where you add antibodies on that catalyse a colour producing reaction. Actin, cadherins, hormone receptors, HER2 receptors and microorganisms can be detected.
Cytokeratins can also be detected by immunohistochemistry, what is the significance of these?
They're only found in epithelia and the type present can indicate the primary site of the carcinoma
What, and what what colour does eosin stain?
cytoplasm and connective tissue pink
What, and colour does haematoxylin stain?
What is molecular pathology?
Look at DNA, uses FISH ect. Identifies which growht factors present for treatment options ect
When are frozen sections used?
used to establish presence or nature of a lesion mid operation which would influence the course of the operation. Accuracy lower but much faster
what are the 4 sections to the histology report?
Why do we still do autopsies?
modern imaging cannot explain everything and is sometimes wrong/ interpreted wrong.
research into neurodegenerative disorders
When is a medicolegal (coroners) autopsy performed?
when deceased ID is unknown
they hadnt seen a dr within 14 days of death
not able to give cause of death
unnatural death (murder)
occupational disease/ accident related to medical treatment or procedure?
What is a forensic autopsy performed?
a subtype of coroners autopsy- performed for suspicious deaths
What is a consent (hospital) autopsy?
Autopsy where consent from next of kin needed, increasingly less common
What is involved in autopsy?
History- limited in coroners autopsy
External examination- natural disease or injury?
Internal examination- all systems examined in most cases but often limited in consent autopsy
What additional tests can/ are ordered after autopsy?
- Histology- usually for making and confirming diagnosis
- Toxicology- blood, urine, bile ect, looking for theraputic and recreational drugs
- Biochemistry- often used for diagnosis of renal failure, diabetic and alcoholic ketoacidosis
State some common causes of sudden death
- extradural haemorrhage
- subdural haemorrhage
- sub arachnoid haemorrhage
- coronary disease
- valvular disease
- ruptured abdo aortic aneurysm
- DVT leading to large pulmonary embolism
- broncho- pneumonia
- peritonitis (usually from ruptured appendix)
When are paediatric autopsies performed?
- deaths in utero
- perinatal deaths
- sudden infant death
- suspicious death