组织学与胚胎学绪论中英.ppt

Histology Introduction Definition: A science: study normal micro-structure(微细结构) its related function of human body.  4 structural levels: Cell: the smallest structural functional unit.  Tissue(组织): groups of cells (similar in morphology or related in function)＋intercellular materials 4 types of fundamental tissue　　 epithelium 上皮组织　　 connective tissue 结缔组织　　 muscular tissue 肌组织 nervous tissue 神经组织　 Why do we study histology ? To complete the knowledge of human body’s structures----from gross to microscopic Be able to understand how the different tissues function----the basis of physiology Can find the diseases only after the normal is known----the basis of pathology It is also a foundation of clinic sciences—for a good doctor needed in future Investigative methods of histology  1. Tissue preparation A. paraffin section preparation石蜡切片术 Specimen取材: as fresh as possible ?Fixation固定: fixative: formalin solution; purpose: to preserve the structural organization Dehydration脱水: replace the water in the tissue by alcohol Clearing透明: replace the alcohol by xylene Embedding包埋: replace the xylene with melted paraffin Sectioning mounting切片 B. Frozen section: Better for preserving chemical components (e.g. enzymes) Freezing→cryostat→staining C. the others: Smear preparations: for blood etc; Grind preparations: for bone  2. Staining染色 Purpose:To make tissue section for observation. H-E Staining: Hematoxylin:苏木精 basic dye, bluish color Eosin:伊红acid dye, pink color Basophilic:嗜碱性components stained with basic dye (H); bluish（nuclear chromatin) Acidophilic:嗜酸性components with an affinity for acidic dye (E); pink (cytoplasm collagen fibe