Flashcards in Histology Deck (171)
The study of microscopic structures and tissues
Why is a high resolution needed?
To observe and discriminate between cell and tissue components
What are the 6 steps in tissue processing?
Fixation, embedding, sectioning, mounting, de-waxing, staining
What is the process of fixation?
Preserves and fixes specimens in place with crosslinks using formaldehyde
What is the process of embedding?
First dehydrate and remove water with alcohol, then clearing using organic solvent, then replacing with wax (58) or resin (60) for physical support
What is the process to sectioning?
Sectioned by a microtome to allow discrimination
What is mounting?
Mounting is the process of mounting tissues to a glass slide to be stained and viewed
What is de-waxing?
The removal of wax or resin to allow staining using organic solvent, then alcohol and then water
Why is staining needed?
to show and distinguish specific features.
What colour are the nucleus and cellular proteins with H and E stain?
DNA/RNA- purple/blue. Intra/extracellular proteins- red
What colour does trichrome stain the nuclei, intracellular and extracellular proteins?
Nuclei varies, intracellular proteins- red/pink, extracellular proteins- blue/green
What are both ordinary CT and cartilage made from?
Cells and extra cellular matrix
What is ordinary CT used for?
Binding muscle to bone and binding individual cells, and allows O2 to diffuse through extra cellular matrix and WBCs
What cells in ordinary CT secrete ECM?
What are mature and dormant fibroblasts called?
What features does a fibroblast cell have?
Prominent nucleus and granular cytoplasm
What is an adipocyte?
What are the two types of adipocytes?
White or brown
What are the functions of adipocytes?
Energy reserves- triglycerides, thermal insulation, shock absorber- spine, hooves, brown fat for rapid heat producer
What causes the pigment of brown fat?
The dense mitochondria to rapidly break down the fat and release heat
What type of fibres are in the ECM?
Collagen, Reticular, Elastic
What colour do collagen fibres stain with H&E and trichrome?
H&E- pink, Trichrome- Blue
Which fibre in ordinary CT is made from abundant proteins assembled into fibres?
Collagen- strong and give tensile strength
What doe reticular fibres form in the liver?
The internal skeleton
Which fibre in ordinary CT can recoil?
Which fibre is needed to limit the stretching of elastic fibres?
What are proteoglycans in the ground substance made from?
GAGs or hydrated sugars attached to a protein core
What are the types of loose connective tissue?
Areolar, adipose and reticular
What are the types of dense connective tissue?
dense regular, dense irregular, elastic