2009 Foundations Histology Expert Tutorial

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Contents

Introduction

  • Wed 25 March 2009 11:00 AM - 12:00 PM Mark Hill

Audio

About Expert Tutorials

  • Ask your SGS for specific topics or questions you would like to ask the Expert Tutor.
    • Prioritize the questions.
    • Submit them by email well before the expert tutorial, as they can them be reviewed by the expert to look for common problems in understanding.
  • Read what the class/lecture is designed to do and the key concepts.
    • Have all the issues been met by the content provided.
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About This Expert Tutorial

  • Don't get too carried away with details remember these are supposed to be introductory.
  • You will cover many of these topics again in other settings during your course.


Science Practical - Introduction to Microscopy

Virtual Microscope - Cells and Tissues
  • Not much to cover from this practical as it was an introduction.
  • Generally we cannot microscopically see tissues unless they have been stained with coloured dyes and labels that bind specifically to cellular and extracellular components.
  • You do not need to know the all the histological stains used, though be aware that hematoxylin and eosin stain (H&E stain), are a quick and good contrast of tissue features.
    • basic dye hematoxylin - colours basophilic structures blue-purple (DNA, RNA)
    • acidic eosin - colours eosinophilic structures pink-red (protein)
  • Some other stains, for reference only Histology Stains
  • Virtual Microscope - Introduction to Microscopy

Lecture - Histology: Cells of the Blood

Fri 13 March 2009 11:00 AM - 12:00 PM Central Lecture Block 7, Kensington

Lecture Foundation Series - Histology: Cells of the blood

This lecture is designed to:

  1. To describe the normal morphology of blood.
  2. The main emphasis will be on the cytological appearance of red blood cells (erythrocytes) and the various main groups of white blood cells (leukocytes).
  3. Functional aspects of erythrocytes and leukocytes will be mentioned.

Key concepts addressed:

  1. To gain an understanding of the various types of cells which exist in blood.
  2. To examine different histological features for each of these types of blood cells.
  3. To gain some insight into their roles in normal body function.

Reference: Junqueira and Carneiro (2005). Basic Histology. 11th Edition. Chapter 12 : Blood Cells. NB: The 11th edition is available online. However students are expected to purchase the 11th edition as one of the required textbooks. Access via Lange Educational Library from Sirius. http://sirius.library.unsw.edu.au


Tutorial Points

Red Blood Cells
Lymphocyte
Eosinophil and Neutrophil

Links:

Science Practical - Introduction to histology - Cells and Tissue

[ Virtual Microscope - Cells and Tissues

Histology terminology

This laboratory class is designed to:

  1. Obtain an understanding of the histological appearance of the basic tissues namely epithelium, connective tissue, muscle and nervous tissue.
  2. To examine unique cellular characteristics of each of the basic tissues.
  3. To correlate the functions of the basic tissues with their morphology.

Key concepts addressed:

  1. A histological examination of selected examples of each of the basic tissues will be addressed.
  2. Identify the various types of tissue characteristics and relate these to their function.
  3. Examine cellular morphology for each of the basic tissues.

Reference: Junqueira and Carneiro (2005). Basic Histology, 11th Edition, General reading of Chapters 4, 5, 6, 7, 8, 9 and 10 to obtain an overview of the basic tissues and the variety of cell types involved. NB: This is available online. However students are expected to purchase the latest edition as one of the required textbooks. Access via Lange Educational Library from Sirius. http://sirius.library.unsw.edu.au

Tutorial Points

  • Basic background to the types of tissues and their organization in the body. Look at examples of these within the lab.
  • Broadly Epithelia or Connective tissue cellular organization
    • most tissues and organs contain both types (for example, skin has an epithelium epidermis and a connective tissue dermis and hypodermis) Integumentary

Epithelia

Epithelia

Structure

  • classified by: number of cell layers (simple, pseudostratified, stratified), cell shape (columnar, cuboidal, squamous) and any specializations.
  • Have a specialized extracellular matrix (ECM) on which basal cells sit, the basal lamina, and generally little or none ECM between the cells.

Function

  • as surfaces or protective boundaries between environments and tissues, secretion or absorption.
Thick Skin
Thin Skin

Connective Tissue

Structure

  • consists of cells separated by varying amounts of extracellular matrix (ECM).
  • classified by ECM components (eg reticular fibres), organization (eg loose connective tissue and dense connective tissues) and cell types (eg adipose)
  • blood is a liquid connective tissue

Function

  • many different functions, support, strength, tissue integrity, connectivity, etc.


Links:

Colleges A & B Histology Questions

  • How do you tell the difference between structures on the slides which appear the same?
    • Through assistance by lecturers, demonstrators, tutors, online support and textbooks.
    • Practice and experience.
    • Look at a range of magnifications, starting with teh lowest to get the overall structure.
  • In the expert tutor's opinion, what are the three most distinctive tissues (in terms of structure) when viewed under light microscopy?
    • Epithelia, connective tissue and muscle (also a connective tissue)
  • We always see slides with H&E. What are the other types of stains, and what colours do they stain features?

  • What are the main different types of stains used and do we ever need to know details about the stains themself?
    • Mainly use hematoxylin and eosin stain (H&E stain), quick and good contrast of tissue features.
    • You need to realise without stains we cannot see tissue structure and the most used stain.
    • basic dye hematoxylin - colours basophilic structures blue-purple (DNA, RNA)
    • acidic eosin - colours eosinophilic structures pink-red (protein)
    • At this stage you do not need to know all the stains and their patterns Histology Stains
  • Can you review the structures of the rib slide again and explain the role of osteoblasts and osteocytes further?
    • Rib Slide Bone Cells
    • osteoblasts are progenitor bone-forming cell that will differentiate into an osteocytes
    • osteocytes are the mature bone-forming cell lying in compact and spongy bone.
  • What are all the types of possible artefacts, and how do each look like?
    • Tears, rips holes in tissue.
    • Tissue section folding.
    • Staining artefacts, precipitated stain.
    • These artifacts will generally be pointed out in your practical classes.
  • What is the best way to distinguish a tear/shrinkage from a lumen/pathological structure?
  • What is the actual function of fascia? and how does it differ from other connective tissues?
  • Apart from originating from the mesoderm like other connective tissues, could you please explain why blood is considered a form of connective tissue?
  • How do you distinguish between fibroblast nuclei and the nuclei of other cells?
    • Not often easy to distinguish, fibroblast/cyte nuclei can be "flattened".
  • Do B or T cells in the body change structurally/functionally (ability to protect against pathogens) as the individual ages?
  • When do B/T cells have the best immune strength and why?
  • Do lymph nodes change structurally/functionally as the individual ages?
  • Can differences in immunological strength be observed histologically?
  • Are there morphological differences between Resting and Active T and B cells? Are there any features to help differentiate between the cells types.
    • I am not sure that we need to go through B/T cells at this point as they were not covered in detail. You will do so at a later stage.
    • Spend more time understanding the basic cells of the blood and general function, as well as broad overview of the different tissues as identified by histology.
  • Are lymph nodes structurally different in different parts of the body? If so, how? Do they produce different T and B cells?
  • Do T and B cells appear different to lymphocytes? How are they visually distinguishable?