BSMT Human Histology Chapter 1 PDF

lOMoARcPSD|43245063 BSMT Human Histology Chapter 1 Medtech (Centro Escolar University) Scan to open on Studocu Studocu is not sponsored or endorsed by any college or university Downloaded by Ma. Theresa Mae Doctora ([email protected]) ...

lOMoARcPSD|43245063 BSMT Human Histology Chapter 1 Medtech (Centro Escolar University) Scan to open on Studocu Studocu is not sponsored or endorsed by any college or university Downloaded by Ma. Theresa Mae Doctora ([email protected])  lOMoARcPSD|43245063 HUMAN HISTOLOGY [LECTURE] TOPIC: M1 - INTRODUCTION TO HUMAN HISTOLOGY ○ DIAGNOSIS of tissues which are altered by MODULE 1: INTRODUCTION TO HUMAN HISTOLOGY disease which can be seen by microscope ○ Diagnostic procedure is involved. Human Histology ○ Also one of the section of laboratory Cytology → “cyto/kytos” + “logos” → study of cell/ formation - structure - function SIGNIFICANCE OF HISTOLOGY TO MEDICAL TECHNOLOGY ○ “cyto/kytos” - cells PROFESSION ○ Specific study of cell Histology Technicians Organization of the Body ○ In USA only ○ Cells → Tissues → Organs → Organ System ○ Studies tissues (biopsy) Pathologist ○ In Philippines BRIEF HISTORY ○ Deals with abnormalities of tissue causing diseases Robert Hooke (17th Century) Discovered Cells ○ RMTs assists the Pathologists ○ They are usually the head of the Laboratory Marcello Malpighi (17th Century) “Father of Histology” DEFINITION OF TERMS Robert Brown (17th Century) Introduce the “Nucleus” -logy/ ‘logos’ - Study of - Henle Published the 1st Human Histology → “histos” + “logos” → Study of microanatomy Histology of cells and tissues/ formation - structure - function ○ “Histos” - Tissue Matthias Schleiden Cell Theory ○ Focuses on tissue Pathology → “pathos” + “logos” → study and diagnosis of Theodore Schwann diseases through microscopic examination of surgically removed organs, tissues, and other body fluids Microscopy: Type of Microscope ○ “Pathos” - disease or suffering Bright Field Microscope ○ Focuses on the diagnosis of a diseases in where ○ most common type that is used you can detect the problem in the removed tissue ○ Usually in Routine Laboratory organ or other body fluid ○ stained tissues are examined with ordinary light; ○ Finding the cause of the abnormal characteristic has optical system: of tissues, organs and other body fluid Condenser – collects & focuses cone of Pathophysiology → “pathos” + “physio” + “logos” → light to object to be studied Systematic study of functional changes in cells, tissue, Objective – interchangeable lens that organs altered by a disease &/or injury project image of object. Near the ○ “Pathos” - disease or suffering specimen ○ “Physio” - normal physiologic process of Eyepiece – “oculars” that give extra human magnification and project image onto ○ studies the mechanism of how the disease is viewer’s retina. Near the eyes developed from that normal physiologic process ○ NOTE: magnifying power of objective x ○ Not for diagnosis procedure unlike pathology, what magnifying power of eyepiece = TOTAL you check is the mechanism involved where in MAGNIFICATION from that normal tissue it became abnormal, what Dark - Field Microscope happened to the tissue? Why did it become non ○ Usually for the detection of a specific bacteria functional? called Treponema Pallidum, it is the causative ○ Normal processes of cells, tissue organs altered agent of syphilis by a disease. ○ illuminate unstained samples causing them to ○ ABOUT MECHANICS, appear lit against dark background Histopathology → “histos” + “pathos” + “logos” → Study of ○ contains special condenser that scatter light so it changes in tissues caused by a disease would reflect off the specimen at an angle ○ “Histos” - tissue ○ “Pathos” - disease or suffering ○ Changes in the tissues specifically Phase - Contrast Microscope Downloaded by Ma. Theresa Mae Doctora ([email protected])  lOMoARcPSD|43245063 WEEK 1 | MODULE 1: INTRODUCTION TO HUMAN HISTOLOGY ○ Used to view living cells because of its high ○ Adjustment Knobs – These are knobs that are refractive index. used to focus the microscope. There are two types ○ enhance contrast for transparent and colorless of adjustment knobs: specimens Fine Adjustment Knob - Electron Microscope Coarse Adjustment Knob - ○ Very minute cells or microorganism ○ Stage - This is the section on which the specimen ○ Usually seen in Reference Laboratory is placed for viewing. They have stage clips ○ TEM = Transmission Electron Microscope holding the specimen slides in place. The most allows resolution of subcellular structures common stage is a mechanical stage, which in very thin tissue sections allows the control of the slides by moving the ○ SEM = Scanning Electron Microscope slides using the mechanical knobs on the stage allows resolution of 3D views of surface instead of moving it manually. of tissues, cells, & subcellular structures ○ Aperture - This is a hole on the microscope stage, through which the transmitted light from the THE MICROSCOPE source reaches the stage. STRUCTURAL PARTS OF THE MICROSCOPE ○ Microscopic Illuminator - This is the ○ Head - This is also known as the body, it carries microscope’s light source, located at the base. It is the optical parts in the upper part of the used instead of a mirror. it captures light from an microscope. external source of a low voltage of about 100v. ○ Base - It acts as microscopes support. It also ○ Condenser - These are lenses that are used to carries the microscopic illuminators. collect and focus light from the illuminator into the ○ Arms - This is the part connecting the base and to specimen. the head and the eyepiece tube to the base of the They are found under the stage next to microscope. It gives support to the head of the the diaphragm of the microscope. microscope and it is also used when carrying the They play a major role in ensuring clear microscope. Some high-quality microscopes have sharp images are produced with a high an articulated arm with more than one joint magnification of 400X and above. allowing more movement of the microscopic head The higher the magnification of the for better viewing. condenser, the more the image clarity. OPTICAL PARTS OF THE MICROSCOPE More sophisticated microscopes come ○ Eyepiece - lens that is near the eyes. also with an Abbe condenser that has a high known as the ocular. This is the part used to look magnification of about 1000X. through the microscope. It's found at the top of the ○ Diaphragm - it's also known as the iris. microscope. Its standard magnification is 10x with It's found under the stage of the an optional eyepiece having magnifications from microscope and its primary role is to 5x – 30x. control the amount of light that reaches ○ Eyepiece Tubes - it's the eyepiece holder. It the specimen. carries the eyepiece just above the objective lens. It's an adjustable apparatus, hence In some microscopes such as the binoculars, the controlling the light intensity and the size eyepiece tube is flexible and can be rotated for of the beam of light that gets to the maximum visualization, for variance in distance. specimen. For monocular microscopes, they are none For high-quality microscopes, the flexible. diaphragm comes attached with an Abbe ○ Objective Lenses - Near the specimen or slide. condenser and combined they are able to These are the major lenses used for specimen control the light focus and light intensity visualization. They have a magnification power of that reaches the specimen. 40x-100x. There are about 1- 4 objective lenses ○ Condenser Focus Knob – this is a knob that placed on one microscope, in that some are rare moves the condenser up or down thus controlling facing and others face forward. Each lens has its the focus of light on the specimen. own magnification power. ○ Abbe Condenser - this is a condenser specially Scanner - Uses Coarse Adjustment Knob designed on high-quality microscopes, which LPO - Uses Coarse Adjustment Knob makes the condenser to be movable and allows HPO - Uses Fine Adjustment Knob very high magnification of above 400X. The OIO - Uses Fine Adjustment Knob high-quality microscopes normally have a higher ○ Revolving Nose Piece – also known as the numerical aperture than that of the objective revolving turret. It holds the objective lenses. It lenses. is movable hence it can revolve the objective ○ The Rack Stop - It controls how far the stages lenses depending on the magnification power of should go preventing the objective lens from the lens. getting too close to the specimen slide which may damage the specimen. It is responsible for Downloaded by Ma. Theresa Mae Doctora ([email protected])  lOMoARcPSD|43245063 WEEK 1 | MODULE 1: INTRODUCTION TO HUMAN HISTOLOGY preventing the specimen slide from coming too far up and hitting the objective lens. TISSUE SECTION Organs are often sectioned to reveal their internal structure ○ Longitudinal Section - is a cut through the long axis of the organ ○ Cross section/Transverse section - is a cut at a right angle to the long axis ○ Oblique section - is a cut made across the long axis at other than a right angle Downloaded by Ma. Theresa Mae Doctora ([email protected])  lOMoARcPSD|43245063 WEEK 1 | MODULE 1: INTRODUCTION TO HUMAN HISTOLOGY TISSUE PREPARATION Preparation of Tissue for Study ○ Fuck Dis CIET Sige Share Mo Lang Steps in the Preparation of REAGENT’S/ EQUIPMENTS IMPORTANCE Tissue Section USED FIXATION Formalin/ Formaldehyde After obtaining a fresh piece of cells or microorganisms from the body, it is rapidly placed in solutions of stabilizing or cross - linking compounds called fixatives. Fixation plays a huge role in preserving the tissue structure and preventing the degradation of enzymes released from an obtained specimen Fix the issue immediately after removal from the body 10% Formaldehyde Solution DEHYDRATION Increasing Concentration of The fixed tissue must undergo dehydration before infiltration with such alcohol media. The process of dehydration is important because it immerses the specimen in an increasing concentration of alcohol to remove water and formalin (a widely used fixative) from the tissue. Removal of water using an increasing concentration of alcohol from 50% to 100%. CLEARING Xylene In this process, the ethanol from the dehydration step is replaced by an organic solvent that is miscible with both alcohol and the embedded medium (Ex. Xylene). Clearing is an important step because it gives the tissue a translucent appearance. Making the tissue have a translucent appearance by removing the reagent prior to this process. Clearing agent is called xylene. INFILTRATION Melted Paraffin Wax Infiltration is an important step because it removes the organic solvent from the clearing step and replaces it with melted paraffin wax. The tissue is placed in this substance until it is infiltrated Filling in the holes of the tissue so that the tissue will not be destroyed in the trimming process. The holes are filled with melted paraffin wax EMBEDDING Melted Paraffin Wax In this step, the paraffin - infiltrated tissue is placed in a small mold with melted paraffin and allows it to harden. The paraffin surrounding the tissue will help in creating stability of the tissue so that it will be capable of being sectioned during microtomy The final product is a tissue block Still uses paraffin wax but you will now form a mold and make a tissue block. TRIMMING Scalpel This step is a process where you remove the excess paraffin block to expose a tissue to a level where a section is obtained. It is usually trimmed at thickness between 10 and 30 μm. Used to exposed the tissue in the middle of the mold before proceeding to sectioning SECTIONING Microtome This step uses a microtome - a machine that cuts the tissue specimen into thin specimens in the form of ribbon that can be placed on a slide for microscopy. Most tissues are cut into 5 μm thickness. WATER BATH The tissue ribbon is placed in a water bath that has a controlled temperature which is at 60 degrees celsius. Then fish the tissue using a microscope slide. The microscope slide contains a Meyer’s Egg albumin which serves as adhesive so that the tissue ribbon will stick in the slide STAINING Hematoxylin & Eosin Stain Staining is mostly done to make the appearance of the specimen (H&E Stain) more visible. Hematoxylin and eosin stain are used to make the tissue structure more visible and easy to observe and evaluate under the microscope. Hematoxylin - color purple; a form of basic dye which is take up by acidic component of cell specifically the nucleus Downloaded by Ma. Theresa Mae Doctora ([email protected])  lOMoARcPSD|43245063 WEEK 1 | MODULE 1: INTRODUCTION TO HUMAN HISTOLOGY Eosin - orange; an acid dye that is take up by basic component of cell like cytoplasmic organelles which are suspended in the cell’s cytoplasm MOUNTING Canada Balsam / Clear Nail The next step, we need to put a drop of Canada Balsam or Clear Nail Polish Polishon (an adhesive) into the specimen in a slide. Then cover the slide with a thin glass coverslip - take note that the coverslip must be free of optical distortion. Coverslip is put in the slide to prevent scratches of the specimen This is done to preserve the stained section of the specimen in the slide. LABELLING Pencil/ Label Marker Labelling the slide with the tissue specimen is an important step in tissue processing. This involves the patient's personal details that should match the details on the ordered test requisitions to avoid any delay in testing and results. cv Downloaded by Ma. Theresa Mae Doctora ([email protected])  lOMoARcPSD|43245063 WEEK 1 | MODULE 1: INTRODUCTION TO HUMAN HISTOLOGY ○ Viscous fluid medium which provides support to TISSUE PROCESSING your cytoplasmic organelles STRUCTURE OF A TYPICAL CELL & MITOSIS WHAT IS A “CELL”? ○ Known as the basic unit of life Ribosomes BASIC FUNCTIONS OF CELLS ○ Composed of protein and rRNA; bound or free ○ Cell metabolism and energy use Bound - nakadikit sa Rough ER ○ Synthesis of molecules [RER, SER, LIPID Free - suspended in cytosol SYNTH, PROTEIN SYNT] ○ Communication [for nerve cells like neuron] ○ Reproduction & Inheritance [Sperm cell and Egg cell] Sperm Cell - the only cell that has the presence of flagellum RBC / Erythrocyte - The only cell in the body which does not contain a nucleus (unucleated cell) PARTS OF THE CELL AND THEIR FUNCTION Plasma Membrane / Cell Membrane / Plasmalemma ○ Phospholipid Bilayer – “amphipathic” in nature [non-polar tail (long chain of fatty acids) / polar head (bears a phosphate group)] ○ Selective permeable boundary of the cell ○ Tail: Non-polar – hydrophobic/water repelling. Endoplasmic Reticulum Bears long chain of fatty acid/ lipid ○ Smooth ER ○ Phosphate Head: Polar – hydrophilic/water ER Lacks bound polyribosomes attracting. Bears the phosphate group Fat (lipid) manufacture & production Steroid & hormone production ○ Rough ER Presence of polyribosomes Production / folding / Quality Control & dispatch of proteins How does quality control happen? From the command center of the cells, nucleus (bears DNA) Cytoplasm - serves as the bed. And it is coated by cell membrane. Cytosol is suspended in cytoplasm where cell organelles floats Cytosol Downloaded by Ma. Theresa Mae Doctora ([email protected])  lOMoARcPSD|43245063 WEEK 1 | MODULE 1: INTRODUCTION TO HUMAN HISTOLOGY Lysosomes ○ Sites of intracellular digestion and turnover of cellular components ○ Suicide bag of the cell. ○ Example, if you are infected by a bacteria, the lysosome will engulf the bacteria, which will be called phagolysosome. ○ After the bacteria is eaten by the lysosome, the The nucleus contains the genetic material of the cell which lysosome itself will burst inside the cell and when is the DNA. it burst, the immune response will be triggered The DNA according to the central dogma of microbiology, undergoes replication and it is transcribed to mRNA which is a process called transcription. mRNA, undergoes translation so that it will be translated into functional protein that the body needs. The nucleus contains its own nuclear membrane and the space between the nucleus and its membrane is called perinuclear space. Perinuclear Space is continuous up to the RER. and this is also where DNA Flows IF the protein is functional, the RER moves the protein via secretory vesicle palabas ng cell IF the protein is defective, the SER moves the protein into the cytosol so that it will be processed again. PARTS OF THE CELL AND THEIR FUNCTION: Cytoplasmic Organelles Golgi Apparatus / Golgi Complex ○ Initiates packing, concentration and storage of secretory product The secretory product are the substances that is released from inside of your cell to outside Mitochondria ○ Aerobic respiration and production of ATP ○ ATP - energy unit of the cell. ○ This is where ATP is produced Secretory Granules / Vesicles ○ Transports cellular material ○ Secretory vesicles contains secretory granules Downloaded by Ma. Theresa Mae Doctora ([email protected])  lOMoARcPSD|43245063 WEEK 1 | MODULE 1: INTRODUCTION TO HUMAN HISTOLOGY Proteasomes ○ Degrades denatured or nonfunctional polypeptides PARTS OF THE CELL AND THEIR FUNCTION: Nucleus Peroxisomes Nucleus - Command Center of the cell ○ Degrades and digest damaged or unneeded protein Nuclear Envelope - Form a selectively permeable barrier between the nuclear and cytoplasmic compartments ○ Perinuclear Space - Nuclear envelope has two concentric membranes separated by this space PARTS OF THE CELL AND THEIR FUNCTION: Cytoskeleton this perinuclear space and the outer nuclear Cytoskeleton - Maintains intracellular structural support membrane is continuous with the RER and organization of cells; facilitates movement of cell ○ Nuclear lamina (inner nuclear membrane) - A Microtubules - Maintains cell shape and rigidity highly organized meshwork of proteins Microfilaments (Actin Filaments) - Maintains cell shape Chromatin - Consists of DNA and all of the associated Intermediate Filaments - Provides structural support; proteins involved in the organization and function of DNA stabilized junctions between the cell Nucleolus - Subdomain of nuclei in cells actively engaged in protein synthesis. Presence of rRNA that is transcribed, processed, and assembled Downloaded by Ma. Theresa Mae Doctora ([email protected])  lOMoARcPSD|43245063 WEEK 1 | MODULE 1: INTRODUCTION TO HUMAN HISTOLOGY MITOSIS Process of Cell Division Stages of mitotic cell divisions include: prophase, when chromosomes condense, the nuclear envelope disassembles, and the microtubular spindle forms; metaphase, when chromosomes are aligned; anaphase, when they begin to separate toward the two centrosomes; telophase, when a nuclear envelope re-forms around the separated chromosomes. Telophase ends with cytokinesis or cell cleavage into two daughter cells by a contractile ring of actin filaments and myosin Downloaded by Ma. Theresa Mae Doctora ([email protected])