Lecture 2.2 Introduction to Histology & Blood Flashcards
What are LM and EM used for?
LM used normally, but EM has higher magnification
What is fixation?
Remove tissues from the body - they would start to autolyse and have bacterial colonisation, so fixatives (formaldehyde) cross link molecules
How thick are tissue pieces cut for cassette?
2mm
What is paraffin embedding?
Paraffin not water soluble so treat tissue with alcohol and xylene to remove water
What are the 4 basic tissue types?
Connective tissue, muscle, nervous tissue, epithelium
What are the features of haematoxylin?
Blue/purple
Binds to anionic, negative, acidic things (components referred to as basilic)
Binds to phosphate groups
What are the features of eosin?
Pink
Binds to positive, cationic components (referred to as acidophilic or eosinophilic)
Binds to amino acids and proteins (cytosol)
What is amphiphilic?
Staining with both H&E dyes
What are the 3 types of plasma?
Coagulators, albumin, globulins
Which adult sex has more RBC?
Males
What are the components of white blood cells and their features?
- Granulocytes: granules in cytoplasm, aka polymorphonuclear cells, multi lobe nuclei (neutrophils, eosinophils, basophils)
- Mononuclear Leukocytes: non lobated, lymphocytes and monocytes
- Neutrophils: motile, 3 types (prim, sec, tert), twice the size of RBC, 3-4 lobes in nucleus, moderate amount of cytoplasm, granules released to cause tissue and bacterial death, rarely found in normal tissues, Barr body in females (inactive x – appendage on nucleus), life span several days, but hours once in tissue (inflammation)
- Eosinophils: bilobed nucleus, allergic reactions against parasites, exocytoses granules, seen along GIT
- Basophils: bilobed nucleus, granules with histamine, similar to mast cells, degranulate in inflam responses
- Lymphocytes: smallest wbc, larger than rbc, thin rim of cytoplasm, 3 types (B,T,NK)
- Monocytes: largest wbc, pale oval nucleus on edge, 2-3 x RBC size, more cytoplasm than lymphocyte, precursor of macrophages
What are the features of RBCs?
7um diamter
45% of blood volume
No nucleus or organelles
120 day lifespan, removed by spleen and liver
Start as reticulocytes (have organelles and RNA to make haemoglobin) - 1% of RBC
Normoblast is immature RBC - not seen circulating
What are the features of platelets?
2-4 um diameter, live 8-10 days, contain granules
What are the types of bone marrow?
Red is active (haemopoietic) and yellow is adipose (50% of adult bone marrow is yellow) - adults only have bone marrow is axial skeleton and proximal femur
Where does haemopoiesis occur in embryo and foetus?
Occurs in yolk sac, then liver and then bone marrow at birth
