Introduction to Histology Flashcards
how can you study the structure of the human body?
gross - by naked eye / without magnification
microscopic - using a light microscope
what are the four steps to studying histology?
- obtain suitable tissue
- process it
- stain it
- magnify
which stains mostly use / what do they show?
Haematoxylin and Eosin (H&E)
stains nuclei blue and cytoplasm and stroma pink
what are histochemical stains?
stains other than Haemtoxylin and Eosin (H&E) stain. These are usually called ‘special stains’ that highlight different tissues with different colours when examined under the microscope
when are immunohistochemical stains (IHC) used?
When cells look similar - e.g. T lymphocytes and B- lymphocyes which under the microscope will have a very similar appearance
what IHC stains made from and how work?
monoclonal or polyclonal antibodies that bind to specific antigenic subcellular targets (epitopes) either on the cell surface or the cytoplasm or within the nucleus (e.g. nuclear transcription factors) that bind with the target and carry a colouring agent (commonly brown colour) that identifies specific cell types
what do IHC stains detect?
specific protein marker
what are epitopes?
specific antigenic subcellular protein targets (epitopes)
what is histopathology?
the study of cells and cellular material, usually ot make diagnosis of diseases and conditions
what is histology?
the scientific study of the fine detail of biological cells and tissues using microscope to look at tissue specimens that have been prepared using histological technique.
why study histology?
study normal structure and be able to diagnose when structural abnormalities - diagnosis / research of disease
patients want to know whats wrong
name 4 types of microscope - why use different?
depends on what you want to see
- light micro:
a) phase contrast
b) dark field - objects appear bright. - fluorescent microscopy - detects naturally fluorescent molecules
- confocal microscopy - scanning system to dissect a specimen optically
- electron microscope
a) Transmission (TEM)
b) Scanning (SEM)
when is dark field light micro useful?
for urine crystals and bacteria?
what are steps for histological lab procedures?
- specimen retrieval - biopsy
- tissue fixation - tissues immersed in preservatives
- grossing - specimen examination and description
- embedding - tissue washed and deydrated in alcohol solutions. occurs in a histokinette. then add tissue with wax
- tissue sectioning - using steel blades called microtome. 3-5 um thichkness.
- staining - reveals structures
what do you use to do tissue fixation?
formalin
