L4 CT Histology BMS 122 PDF

Textbook guide General Histology for Faculty of Dental Students BMS 122 Junqueira's Basic Histology, Text F A L L 2 0 2 4 and Atlas. Mescher, 15th Edit...

Textbook guide General Histology for Faculty of Dental Students BMS 122 Junqueira's Basic Histology, Text F A L L 2 0 2 4 and Atlas. Mescher, 15th Edition, 2018 T H E F U T U R E S T A R T S H E R E  INTENDED LEARNING OBJECTIVES (Ilos) By the end of this lecture you should be able to identify the:  Histological characters of connective tissue (CT).  Histological structure of connective tissue.  Types of connective tissue cells.  Types of connective tissue fibers.  Types of connective tissue.  Types of connective tissue proper.  There are four basic tissues which include: 1) Epithelium 2) Connective tissue 3) Muscular tissue 4) Nervous tissue All of them are composed of:  Cells &  Extracellular matrix (ECM) in different proportions  Characters of connective tissue 1) Abundant extracellular matrix (ECM) & widely separated cells. 2) Penetrated by blood vessels, lymphatics and nerves. 3) Supportive, nutritive & protective for other tissues & organs. 4) Variation in CT types is mainly due to the difference in the composition and structure of ECM & cells. epithelium Connective tissue Connective tissue  Histological structure of connective tissue Extracellular Cells matrix (ECM) Ground substance Protein fibers and interstitial fluid Components of CT Cells Matrix Fibers According to the consistency of matrix Soft ……… CT proper Rubbery …….. Cartilage Hard ………. Bone Fluid ……… Blood  CT proper Cells Fibers Matrix Fixed Collagenous Soft (jelly Free Elastic like) Reticular  Cells of connective tissue proper Fixed Free  Free macrophage  Fibroblasts  Mast cells  Adipocytes (Fat cell)  Plasma cells  Fixed macrophages  White blood cells ‘leucocytes’ Connective tissue cells (Branched& nonbranched) Macrophage Plasma cell Fibroblast Mast cell Fat cell  Fibroblasts The most common cell type LM: - Branched cells - Basophilic cytoplasm “RER” - Central oval, pale (vesicular) Nucleus Function: Synthesis of the ground substances & fibers Fibrocyte Types: 1- Active (fibroblasts) 2- Inactive (fibrocytes) Fibroblast  Adipocytes (white fat cells) LM : - Large oval cells - Cytoplasm: thin rim around one huge lipid droplet - Nucleus: flattened and peripheral Adipocytes - With H & E stain: signet ring appearance - Special stain: Sudan III (Orange) Function:  Storage of fats  Heat insulator  Macrophages LM: - Irregular shape: - Cytoplasm: many lysosomes and well developed Golgi - Nucleus: kidney-shaped Function:  Phagocytosis of any foreign particles or foreign organisms  Immunological role  Form multinuclear giant cells to engulf & digest large foreign bodies  Mast cell LM: - Rounded cell - Filled with basophilic secretory granules - central &rounded nucleus. - Stained metachromticaly by toluidine blue Function:  Responsible for allergic reaction (secrete histamine and heparin)  Plasma cells Origin: B lymphocytes LM: - Oval cell - Cytoplasm: basophilic cytoplasm (RER) - Nucleus: clock face nucleus - - ve Golgi image Function: - Immunological role - Production of antibodies  Connective tissue fibers Collagen fibers: Elastic fibers: Reticular fibers:  Acidophilic by H&E  Faintly acidophilic by H&E  Not seen with H & E  Rigid & non-stretchable  Stained brown with Orcein  Stained black with Silver (Ag)  Stretch &recoil  Supportive stroma (background)  Types of CT Proper It is classified according to the relative abundance of basic components into: Loose CT Dense CT Loose areolar CT White All over the body except the brain fibrous(Collagenous) CT a)Regular (tendons) b)Irregular (dermis of the skin) Reticular CT Yellow elastic CT Stroma of organs Blood vessels Adipose CT Subcutaneous tissue& around the kidney Mucoied CT Pulp of the tooth  Main types of CT  Four main types CT proper (Fibrous) soft matrix 1. Mucoied 2. Loose (areolar) 3. Adipose 4. Reticular 5. Elastic 6. Dense – Regular – Irregular Cartilage rubbery matrix 1. Hyaline 2. Fibrocartilage 3. Elastic Bone solid matrix 1. Compact bone 2. Cancellous bone Blood fluid matrix  Types of Connective Tissue Proper  Few cells (fibroblasts,  Mainly adipocytes  Many cells (all types) fibrocytes) (fat cells)  Few fibers (all types)  Mainly collagen bundles  Mammary gland  Mainly ground substances 1. Regular (Tendons)  Subcutaneous tissue  All-over the body except 2. Irregular (Dermis of skin)  Around kidney brain  Other types of connective tissue Cartilage: Bone : Blood :  Cartilage cells  Bone cells  Cells:  Matrix  Matrix - RBCs - White blood cells - Platelets  Plasma  ASSIGNMENT 2 1- Enumerate four types of CT proper and mention one site for each. 2- List three types of CT cells and mention one function for each. 3- List the special stains you have studied and what structure it stains.