Faculty of Science

Objectives

This course is designed to give an understanding of the nature of cells of the body, tissues and their functions, processing and examination of tissues and cells in histopathology.

Contents

A. Introduction to the cell, functions of organelles; An overview of light microscope, study of sections under the microscope, Appearance of cells in H and E sections

B. Tissues; epithelial tissues, epithelial membranes, simple epithelium (simple squamous epithelium, simple cuboidal, simple columnar, goblet cells), Pseudostratified epithelium (Pseudostratified ciliated columnar), stratified epithelium (stratified columnar epithelium, transitional epithelium, stratified squamous nonkeratinizing and keratinizing epithelium)

C. Cell junctions, tight junctions, adhering junctions, epithelial junctions, exocrine and endocrine glands

D. Connective Tissues

• Loose Connective tissue and adipose tissue; connective tissue fibers (collagen fibers, elastic fibers, reticular fibers), tissue fluid and lymph, basement membrane, connective tissue cells (fibroblast, endothelial cell, pericytes, fat cells and adipose tissue, plasma cells, mast cells, macrophages)

• Dense connective tissue; Cartilage, bone and Joints, tendons, ligaments, cartilage (hyaline cartilage, fibro cartilage, elastic cartilage)

• Bone-bone canaliculi and nutrition, bone growth, mechanisms of osteogenesis, growth of cancellous bone, development of compact bone, osteogenic cells, osteoblast, bone matrix, osteocytes, osteoclast, and joints

E. Examination of Tissues

• Examination of Tissues; Fresh specimens (frozen sections, teased sections, squashed preparations, impression smear)

• Fixed tissues (frozen sections, paraffin sections, celloidine and low-viscosity nitrocellulose sections, resin sections)

F. Tissue Processing

• Fixation of tissues, definition of fixative, characteristics of a good fixative, simple fixatives

• Compound fixatives (micro-anatomical fixatives, cytological fixatives, nuclear fixatives, cytoplasmic fixatives).

G. Fixation of smears; fixation of gross specimens, secondary fixation, post chromatization, washing out

H. Decalcification; selection of tissue, technique of decalcification, and assessment of decalcification; Decalcifying solutions, ion exchange resins, chelating agents; Dehydration, Impregnation, Embedding; Selection of tissue, Paraffin wax technique, dehydration, clearing; Impregnation with paraffin wax-tissue density and size of block tissue, automatic tissue processor. Vacuum impregnation technique; moulds for embedding, technique for embedding-plastic embedding cassettes and glass tubing; Gelatin embedding, celloidine, low viscosity nitrocellulose (LVN)

H. Tissue Processing

• The microtome; Cambridge rocking microtome, rotary microtome, base sledge microtome, sliding microtome, freezing.

• Cryostat, microtome knives, Tissue sectioning, preparation of tissues

• Preparation of frozen sections, preparation of cryostat sections, preparation of celloidin sections

• Staining : Natural dyes, synthetic dyes, basic acid/neutral dyes, staining properties of dyes, the theory of staining; Staining equipment, procedure for staining paraffin wax sections, staining frozen sections, pigments, mounting of sections and media-aqueous, resinous and synthetic mountants, haematoxylin staining solutions for cell nuclei, different staining techniques and results

I. Introduction to Cytologic Techniques

• Introduction, fixation, preparation of smears (vaginal, sputum, cervical smears, smears from urine, pleural, ascitic fluid and gastric washings, membrane filters).

• Staining technique; papanicolaou staining method, hormone assessment, additional methods, sex chromatin (Barr bodies)