Chapter 1 ntroduction
Chapter 1 Introduction
What's histology Il, Why We study it? How to study it -Histological methods
I. What’s histology? II. Why we study it ? III. How to study it ?-Histological methods
1. What's histology? Histology (Greek words) /histo-tissue nlogia-study of, or knowledge of So, histology means the knowledge of tissue, is a branch of Anatomy. Anatomy gross anatomy microscopIc anatomy Structures related to function. So, exactly, Histology is a science which study the microstructure and the relationship between the structure and function of human being
I. What’s histology? Histology (Greek words): /histo-tissue /logia-study of ,or knowledge of So, histology means the knowledge of tissue, is a branch of Anatomy. Anatomy: ---gross anatomy ---microscopic anatomy Structures related to function. So, exactly, Histology is a science which study the microstructure and the relationship between the structure and function of human being
Cell: smallest unit of structure and function of body tissue group of cell+extracellular ground substance four basic tissue epithelium ↓/- connective tissue ---muscular tissue nervous tissue organ: made up of tissue, have special shape structure and function system organs Which have related function get together
Cell: smallest unit of structure and function of body ↓ tissue: group of cell+extracellular ground substance four basic tissue: ---epithelium ↓ ---connective tissue ---muscular tissue ---nervous tissue organ: made up of tissue, have special shape, structure and function ↓ system: organs Which have related function get together
What's Embryology? Embryology is a kind of science which study the/processes and the regulations of the development of human fetus
II.What’s Embryology? Embryology is a kind of science which study the processes and the regulations of the development of human fetus
l. How to study it histological methods Development of histology deponds on the development of technique. Histology studies the microstructures. So, we should have the aid of microscope to study Several types of microscopes are available According to the light source used microscopes can be basally classified as e light microscope(LM) e electron microscope (EM)
III. How to study it- histological methods ---Development of histology deponds on the development of technique. ---Histology studies the microstructures. So, we should have the aid of microscope to study. Several types of microscopes are available. According to the light source used, microscopes can be basally classified as: light microscope(LM) electron microscope(EM)
1. structure of Microscope LM EM useful magnification : 1500X 800,000X resolution 0.2um 0.2nm
1. structure of Microscope LM EM ---useful magnification: 1500X 800,000X ---resolution: 0.2um 0.2nm
2. Preparation of tissue for LM The most routine one is paraffin section stained with hematoxylin and eosin (H&E The steps a. obtaining th specimen: fresh, small pieces (less than 5mm3)tissue block b Fixation fixatives: use formalin or bouin 's to preserve structural organisation C. Dehydration: use ethyl alcohol to get rid of water of tissue and cell
2. Preparation of tissue for LM The most routine one is paraffin section stained with hematoxylin and eosin(H&E) The steps: a. Obtaining th specimen: fresh, small pieces ( less than 5mm3 )-tissue block b. Fixation: fixatives: use formalin or Bouin’s to preserve structural organisation c. Dehydration: use ethyl alcohol to get rid of water of tissue and cell
d. Clearing: use xylene to get rid of alcohol alcohol and xylene are embedding mediums e. Embedding: firstly, heat the paraffin, make it melt, then put tissue block into melted paraffin allow parafin harden, the tissue block is embedded in
d. Clearing: use xylene to get rid of alcohol *alcohol and xylene are embedding mediums e. Embedding: firstly, heat the paraffin, make it melt, then put tissue block into melted paraffin, allow paraffin harden, the tissue block is embedded in
Sectioning use microtome to cut the tissue into 3-8um thick sections, then monted them on glass slides g /H&E staining Hematoxylin basic stain, combines with acidic components, make them appear blue colour- we call/ such components as basophilic -Eosin: acidic stain, combines with basic components, make them appear pink colour We call such components as acidophilic(eosinophilic)
f. Sectioning: use microtome to cut the tissue into 3-8um thick sections, then monted them on glass slides g. H&E staining ---Hematoxylin: basic stain, combines with acidic components, make them appear blue colour- we call such components as basophilic ---Eosin: acidic stain, combines with basic components, make them appear pink colourwe call such components as acidophilic(eosinophilic)
