Cytology, Embryology and Histology Lecture 1 (PDF)

CYTOLOGY, EMBRYOLOGY AND HISTOLOGY ZOOLOGY(BIOL103) FOR FIRST LEVEL OF APPLIED BIOTECHNOLOGY PROGRAM PROFESSOR DR. HALA GALAL EL-TANTAWI PROFESSOR OF CELL BIOLOGY AND HIS...

CYTOLOGY, EMBRYOLOGY AND HISTOLOGY ZOOLOGY(BIOL103) FOR FIRST LEVEL OF APPLIED BIOTECHNOLOGY PROGRAM PROFESSOR DR. HALA GALAL EL-TANTAWI PROFESSOR OF CELL BIOLOGY AND HISTOLOGY Prof. Hala EL-Tantawi  ‫‪Prof. Hala EL-Tantawi‬‬ ‫‪2‬‬ ‫ﺗﻮﺯﻳﻊ ﺳﺎﻋﺎﺕ ﺍﻟﺘﺪﺭﻳﺲ ﻭﺩﺭﺟﺎﺕ ﺍﻟﻤﻘﺮﺭ‬ ‫ﻣﺠﻤﻮﻉ‬ ‫ﺍﻟﺪﺭﺟﺔ‬ ‫ﻣﺪﺓ‬ ‫ﻋﺪﺩ‬ ‫ﺍﻟﺴﺎﻋﺎﺕ ﺍﻷﺳﺒﻮﻋﻴﺔ‬ ‫ﺍﻟﺪﺭﺟﺎﺕ‬ ‫ﺍﻟﺴﺎﻋﺎﺕ ﺍﻻﺧﺘﺒﺎﺭ‬ ‫ﻧﻈﺮﻯ‬ ‫ﻋﻤﻠﻰ‬ ‫ﺷﻔﻮﻯ‬ ‫ﻭﺍﺟﺒﺎﺕ‬ ‫ﺍﺧﺘﺒﺎﺭﺍﺕ‬ ‫ﺣﻀﻮﺭ‬ ‫ﺍﻟﻤﻌﺘﻤﺪﺓ‬ ‫ﻋﻤﻠﻰ‬ ‫ﺗﻤﺎﺭﻳﻦ‬ ‫ﻧﻈﺮﻯ‬ ‫ﻧﻬﺎﺋﻰ‬ ‫ﻧﻬﺎﺋﻰ‬ ‫ﻗﺼﻴﺮﻩ‬ ‫‪75‬‬ ‫‪25‬‬ ‫‪22.5‬‬ ‫‪2.5‬‬ ‫‪5‬‬ ‫‪15‬‬ ‫‪2.5‬‬ ‫‪2 hrs.‬‬ ‫‪3hrs.‬‬ ‫‪2 hrs.‬‬ ‫‪-‬‬ ‫‪1 hrs.‬‬  ‫‪Prof. Hala EL-Tantawi‬‬ ‫ﺗﻮﺯﻳﻊ ﺩﺭﺟﺎﺕ ﺍﻟﻨﻈﺮﻯ )‪(٥٠‬‬ ‫‪3‬‬ ‫‪Quiz‬‬ ‫‪10‬‬ ‫‪Week 4‬‬ ‫ﻭﺍﺟﺒﺎﺕ‬ ‫‪5‬‬ ‫‪Project‬‬ ‫ﺣﻀﻮﺭ_ ﻏﻴﺎﺏ‬ ‫‪2.5‬‬ ‫‪-‬‬ ‫ﺍﻟﻨﻈﺮﻱ ﺍﻟﻨﻬﺎﺋﻲ‬ ‫‪25‬‬ ‫‪Week 14‬‬ ‫ﺍﻟﻨﻬﺎﺋﻲ‬ ‫‪50‬‬ ‫ﺗﻮﺯﻳﻊ ﺩﺭﺟﺎﺕ ﺍﻟﻌﻤﻠﻰ )‪(٢٥‬‬ ‫ﺍﺧﺘﺒﺎﺭ ﻧﺼﻔﻲ‬ ‫‪7.5‬‬ ‫‪Week 4‬‬ ‫ﺍﻟﺸﻔﻮﻱ‬ ‫‪2.5‬‬ ‫‪week 13‬‬ ‫ﺣﻀﻮﺭ_ ﻏﻴﺎﺏ‬ ‫‪2.5‬‬ ‫‪-‬‬ ‫ﺍﻟﻌﻤﻠﻲ ﺍﻟﻨﻬﺎﺋﻲ‬ ‫‪12.5‬‬ ‫‪Week 13‬‬ ‫ﺍﻟﻨﻬﺎﺋﻲ‬ ‫‪25‬‬  Prof. Hala EL-Tantawi. 4 INTRODUCTION & AIM OF THE COURSE Course description: This course introduces the principles and basic concepts of cytology, histology and embryology. Emphasis is placed on the differences between prokaryotic and eukaryotic cells. The cell theory, basic cell structure and functions of the cellular organelles, cell cycle, mitosis and meiosis in the animal cell. Also, identification of the early stages of the embryogenesis. In addition, study of the basic types of the animal tissues (epithelial, connective, muscular and nervous tissues), and other related topics. Upon completion, students are able to understanding the life at the cellular levels.  Prof. Hala EL-Tantawi 5 CYTOLOGY Cell biology is the science that deals with the study of cells, especially their structure, function, life cycle, division, and death. Living things are constructed of cells and they may be unicellular or multicellular. Cells are the smallest living unit and most of them are microscopic. Cell structure is diverse, but all cells share common characters.  Prof. Hala EL-Tantawi 6 CELL DIVERSITY Cells within the same organism show diversity in size, shape, and internal organization. Cell size: cells range in size from one micrometer to one millimeter. Most cells are visible only under microscope. Cells need a large surface area of plasma membrane to adequately exchange materials.  Cell shape: cell forms varied between different parts of the organism. This diversity depends on its function. 7 Prof. Hala EL-Tantawi  Prof. Hala EL-Tantawi 8 CELL THEORY STATES The cell theory state on three main points as following: 1. All organisms are composed of one or more cells. 2. Cells are the basic unit of structure and function in organisms. 3. All cells come only from other cells by cell division.  Prof. Hala EL-Tantawi 9 MICROSCOPY Microscopes are instruments for viewing objects that are too small to be seen easily by the naked eye. Moreover, they are essential tools of cell biologists. Types of microscopes: according to how the image is created. 1- Light Microscopy It uses light to create specimen image. Lenses are glass. In which, light pass-through specimen and focused by glass lenses and then image formed on human retina (eye).  Prof. Hala EL-Tantawi 10 Important terms Resolution: the smallest distance needed between 2 objects so that both are seen. Contrast: More shades decrease the contrast but increases the amount of information (also called dynamic range). Depth of Field: Refers to the thickness of the specimen that will be in acceptable focus. Magnification: The total magnification is commonly obtained by multiplying the magnification power of the objective and ocular lenses together.  Prof. Hala EL-Tantawi 11 Modifications of light microscopes  12 Prof. Hala EL-Tantawi 1. Fluorescence and ultraviolet microscopes Absorb light at one wavelength and emit light at a specific and longer wavelength Major Function: Localization of specific cellular molecules example proteins. Fluorescent dyes or proteins (Fluorochromes) – fluorochromes may be indirectly or directly associated with the cellular molecule. – Multiple fluorochromes may be used simultaneously.  Prof. Hala EL-Tantawi 13 Ultraviolet light is used in these microscopes as a source of light. Acridine orange is commonly used as a fluorescent stain since it combined with nucleic acid (DNA & RNA) in the cells. In this technique, the DNA-acridine orange complex emits a yellowish-green light, whereas the RNA- RAT INTESTINAL CELL Acridine orange complex emits a reddish-orange light WALL – GLUT 2 The amount of DNA and RNA can also be measured by a “cytophotometer” including an ultraviolet microscope. Fluorescent protein in live cells  2. PHASE-CONTRAST MICROSCOPE It is used to examine unstained tissues. When light passes through the cell, the lens system of the phase-contrast microscope acts mainly to increase the differences between the refractive indexes of the different cellular structures. This creates a difference in light intensity giving a good contrast between the cell organelles in unstained fixed or living preparations. Prof. Hala EL-Tantawi 14  Prof. Hala EL-Tantawi 15 ELECTRON MICROSCOPY It uses beams of electrons to produce images. Wave length of electron beam is much shorter than light, resulting in much higher resolution. Max magnification is more than 1,000,000X. The specimen has to be specially prepared and held inside a vacuum chamber from which the air has been pumped out (because electrons do not travel very far in air). Electrons scatter when they pass through thin sections of a specimen. Transmitted electrons (those that do not scatter) are used to produce image. The image is formed as a photograph (called an electron micrograph) or as an image on a TV screen. ELECTRON MICROSCOPY 1. TRANSMISSION ELECTRON MICROSCOPE (TEM). 2. SCANNING ELECTRON MICROSCOPE (SEM). Prof. Hala EL-Tantawi 16  Prof. Hala EL-Tantawi Images of Transmission 17 electron Microscope A- Transmission electron microscope: It gives two dimensional images. It reveals internal cell structure. Max magnification is more than 1000.000X. Specimen preparation is analogous to procedures used for light microscopy, but specimens must be cut very thin. In which, Electrons passed through specimen and focused by magnetic lenses, then image formed on fluorescent screen Hepatocyte similar to TV screen. Image is then photographed.  Prof. Hala EL-Tantawi Images of Scanning Electron 18 Microscope B- Scanning electron microscope: This microscope reveals the specimen surface topography. It produces a 3-dimensional image of specimen’s surface features. Uses electrons reflected from the surface of a specimen to create image. In which, specimen sprayed with thin coat of metal. Electron beam scanned across surface of specimen, metal emits secondary electrons, emitted electrons focused by magnetic Pollen grains lenses. Image formed on fluorescent screen similar to TV screen. Image is then photographed.  Prof. Hala EL-Tantawi 19 Methodology and manipulation of specimens  In the smear technique, the tissue to be examined is 1. SMEAR TECHNIQUES either pressed against a slide or spread with a platinum loop. Human sperm Human blood film 20 Prof. Hala EL-Tantawi  Some living cells take up certain dyes (vital stains) 2. VITAL STAINING which color selectively certain elements in the cells. Alizarin Blue stain 21 Prof. Hala EL-Tantawi 3. PARAFFIN SECTIONS Prof. Hala EL-Tantawi 22  The cryostats were designed to working in temperature (-16O C to -18O C). 5. CRYOSTATS In frozen tissue, the water could be regarded as the embedding medium. Prof. Hala EL-Tantawi 23  Prof. Hala EL-Tantawi 24 Special techniques a. Immunohistochemistry When the body is exposed to foreign substances (antigen or immunogens), the body responds by producing antibodies (immunoglobulin) that bind strongly to the antigens and result in neutralization of foreign substances.  Prof. Hala EL-Tantawi The immunohistochemical technique is based on the 25 combination of labelled antibodies to their antigens (antigen- antibody reactions). This technical variety depends on using antibodies labelled with fluorescent compounds, reddish horse peroxidase localize specific proteins, nucleic acids or polysaccharides. The resulted compounds can be visualized with fluorescence, light or electron microscope. The method of immunohistochemical localization of antigen is either direct or indirect.  Prof. Hala EL-Tantawi In the direct method, antibodies to the proteins being studied are 26 prepared injecting a highly purified preparation of that protein into a live animal of a different species. Circulating antibodies are produced in response to the foreign protein, which acts as an antigen. The antibodies are isolated from the blood plasma and labelled. The labelled antibody reaction is permitted to react with tissue sections. After allowing an antigen-antibody reaction to occur, the excess antibody is washed away. The protein, now combined with labelled antibody, can be detected.  Prof. Hala EL-Tantawi 27 In indirect method, many processes are carried out as follow: 1. The target protein is injected into an animal such as a rabbit. 2. Upon injection, antibodies (immunoglobulins) to the antigen (target protein) are produced in the animal. 3. Rabbit immunoglobulins are injected to another animal such as sheep (acting as antigen to that animal) thus producing an anti-antibody. 4. A tissue section containing the target protein is incubated with labelled rabbit anti-antibodies, and the location of the target protein can be visualized by a microscopic technique appropriate for the label.  Prof. Hala EL-Tantawi DIRECT AND INDIRECT METHODS OF 28 IMMUNOHISTOCHEMISTRY  Prof. Hala EL-Tantawi IMMUNOHISTOCHEMICAL STAIN 29 Tumor marker (KI67) in common oral and maxillofacial lesion  B. RADIOAUTOGRAPHY Radioautography (RAG) is a technique designed to show the pattern of the positioning of different compounds labeled with radioactive isotopes (RI) in specimens. The physical techniques using RI-labeled compounds and the histochemical techniques are employed by RAG. 30 Prof. Hala EL-Tantawi