MICROSCOPY WEEK 1 LEC

• What is histology?

  The study of tissues and their arrangement
• What are the two components of tissues?

  Cells and the extracellular matrix
• How do cells influence the extracellular matrix?

  Cells produce ECM and are influenced by it
• What is the role of the extracellular matrix?

  Supports cells and transports nutrients
• What happens to cells during development?

  They become functionally specialized with matrix
• What is the most common procedure in histologic research?

  Preparing tissue slices or sections
• Why are translucent sections cut from tissues?

  To allow light to pass through for examination
• What is fixation in histology?

  Placing tissue in chemical solutions to preserve it
• What is a widely used fixative for light microscopy?

  Formalin, a buffered isotonic solution
• Why is fixation critical in histological preparation?

  It preserves tissue for subsequent processing
• What is dehydration in histology?

  Removing water from tissue using alcohol
• What is the typical dehydration sequence for specimens?

  70% ethanol, 90% ethanol, 100% ethanol
• What is the purpose of clearing in histology?

  To remove alcohol and fat from tissue
• What is used to replace ethanol during clearing?

  Xylene is used for immersion
• What happens during infiltration in histology?

  Tissue is placed in melted paraffin wax
• What is embedding in histology?

  Placing paraffin-infiltrated tissue in a mold
• What is trimming in histology?

  Cutting embedded tissues into thin sections
• What is the purpose of staining in histology?

  To enhance contrast and visualize tissue components
• What are common stains used in histology?

  Hematoxylin and Eosin (H&E) stains
• What does Hematoxylin stain?

  It stains nuclei blue/purple
• What does Eosin stain?

  It stains cytoplasm and extracellular matrix pink
• What is the purpose of mounting in histology?

  To preserve stained sections for storage
• What is the purpose of microscopic examination?

  To study tissues using a microscope
• What are common types of microscopes used in histology?

  Light microscopy and electron microscopy
• What is a compound light microscope?

  A microscope with multiple lenses and light source
• What do ocular lenses do in a microscope?

  Magnify the specimen typically by 10× or 15×
• What are the objective lenses used for?

  To provide varying levels of magnification
• What is the magnification of low power objectives?

  4× or 10× for scanning
• What is the purpose of the light source in a microscope?

  To provide illumination for magnification
• What does the condenser do in a microscope?

  Focuses and concentrates light into the specimen
• What is the function of the iris diaphragm?

  Adjusts light amount for contrast and resolution
• What is the base of a microscope?

  Provides support for the microscope
• What is the arm of a microscope used for?

  Supports and holds the magnifying system
• What is the stage of a microscope?

  The flat platform where the slide is placed
• What do stage control knobs do?

  Allow precise movement of the slide
• What is the body tube of a microscope?

  Connects the eyepiece to the objective lenses
• What does the coarse adjustment knob do?

  Moves the stage for general focusing
• What is the fine adjustment knob used for?

  Allows precise focusing with high-power objectives
• What is the nosepiece of a microscope?

  Holds the objectives at the end of the body tube
• What is the head of a microscope?

  The upper part that holds the ocular lens