Transcript Histology
Histology Histopathology, the microscopic study of diseased tissue, is an important tool in anatomical pathology, since accurate diagnosis of many diseases usually requires histopathological examination of samples. Histology Processing • Samples fix in 10% NBF. – 48hrs -72 hrs -days • Paraffin infiltration and embedding into blocks. • Cuts thin sections on slides (3-5um thick). 1. Place slides into slide holder. 2. Make up solutions of Clear-Rite (x3), 100% C2H5OH (x3), 95% C2H5OH, 80% C2H5OH, 70% C2H5OH and water. Deparaffinization and Rehydration 3. Follow the schematic below: ClearRite ClearRite ClearRite 100% Ethanol 100% Ethanol 100% Ethanol 95% Ethanol 80% Ethanol 75% Ethanol Water 4 minutes 4 minutes 4 minutes 50 Dips 50 Dips 50 Dips 20 Dips 20 Dips 20 Dips 10 Dips NB: After slides have been deparaffinised, it is important to ensure that they do NOT dry out completely. To avoid this, transport and keep in water or Tris buffer between stages if delays are unavoidable. Stain tissue sections • Hematoxylin and eosin stain (H & E stain) – structures staining blue are called basophilic because of their affinity for the basic dye (hematoxylin) – structures staining pink are called acidophilic because of their affinity for the acid dye (eosin), Liver • Hepatocytes – functional liver cells • Hepatic Sinusoids – small blood vessel within liver tissue • Hepatic Portal Vein – brings blood into the liver • Central Vein – takes blood out of the liver • Bile Duct – storage and drainage of bile • Arteriole – delivers blood from artery to capillaries • Glycogen Vacuole – used for glycogen storage Liver Hepatic sinusoid Hepatocyte Glycogen vacuole 1000X Liver Hepatic sinusoids Erythrocytes visible within the central vein 400x Liver Arteriole 400X Liver Central vein RBC Arteriole Liver Bile Duct Liver Bile Duct Liver White Blood Cells Head Kidney • Interrenal gland – Is a cortisol producing tissue.. • Chromaffin cell – neuroendocrine cells that catalyze and secrete epinephrine, norepinephrine, and other hormones • Postcardinal vein – Blood transport • Hematopoietic tissue – where new blood cells are formed Head Kidney 400x A B A. Interrenal Gland B. Chromaffin Cell C. Postcardinal vein C Head Kidney Cardinal Vein Interrenal cells Chromaffin cells Trunk Kidney • Nephron – a renal tubule that removes waste and helps maintain homeostasis • Renal corpuscle – Glomerulus – Pressure filters blood plasma into Bowman’s capsule – Basement membrane – glomerulus membrane that does the blood filtering – Bowman’s capsule – collects filtered blood plasma and connects with proximal tubule • Proximal tubule – selectively transports nutrients (amino acids, glucose, salt, ect.) back into the blood • Distal tubule – tubular secretion of molecules to balance pH Melanocytes – pigment cells • Collecting duct and/or Mesonephric duct – collects urea from multiple nephrons and controls futher water reabsorption • Connective tissue – fibres surrounding ducts Trunk Kidney Distal tubules Proximal tubules Renal corpuscle Trunk Kidney Basement membrane Bowmans capsule Glomerulus Trunk Kidney 400x C A B A. Mesonephric Duct B. Melanocytes C. Connective tissue Gills • Filament – threadlike structure forming respiratory surface • Lamella – fingerlike projections of the filament • Goblet (or mucous) cell – secret mucus • Chloride cell – acid/base regulation by Cl- and HCO3- excretion – Cells surface area becomes enhanced during alkalosis and decreases during acidosis • Pillar (or pilaster) cell – lend support for lamelle • Gill filament cartilage – center of filament for structural support Lamella Gill A. Filament cartilage B. Pillar cell B C. Chloride cell C A 40x Gill filaments and lamellae Gill Epithelial cells Goblet cells Gill Chloride cell Pillar cells Erythrocytes Laboratory Steps • Use proper microscope handling procedures (distributed in Lab 2) • Examine histology slides of liver, kidney, and gills • Examine additional histology slides of other organs