2009 Foundations Histology Expert Tutorial
From Cellbiology
Contents
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Introduction
- Wed 25 March 2009 11:00 AM - 12:00 PM Mark Hill
Audio
- Link to Foundations Expert Tutorial - Histology Audio Recording 23 Mb MP3
- Please refer to your original Lecture/Practical recordings and notes for complete content information. You can always let me know by email if I have made a mistake in the above audio recording.
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.
- Make sure you have something to report back.
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:
- To describe the normal morphology of blood.
- The main emphasis will be on the cytological appearance of red blood cells (erythrocytes) and the various main groups of white blood cells (leukocytes).
- Functional aspects of erythrocytes and leukocytes will be mentioned.
Key concepts addressed:
- To gain an understanding of the various types of cells which exist in blood.
- To examine different histological features for each of these types of blood cells.
- 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
- This is an introduction to blood, you need to understand general concepts about the cells in the blood. So just the basics!
- Two main types Erythrocytes (red) and Leukocytes (white)
- Erythrocytes
- Structure - mature cells have no nucleus, common size
- Function - oxygen and carbon dioxide carrying
- Leukocytes
- Structure - variable based upon type, can also change with differentiation and location.
- Function - dependent upon cell type: immunity (B and T), clotting, tissue maintenance and many more....
- This is a good overview All the cellular elements of blood, including the lymphocytes of the adaptive immune system, arise from hematopoietic stem cells in the bone marrow
Links:
Science Practical - Introduction to histology - Cells and Tissue
[ Virtual Microscope - Cells and Tissues
This laboratory class is designed to:
- Obtain an understanding of the histological appearance of the basic tissues namely epithelium, connective tissue, muscle and nervous tissue.
- To examine unique cellular characteristics of each of the basic tissues.
- To correlate the functions of the basic tissues with their morphology.
Key concepts addressed:
- A histological examination of selected examples of each of the basic tissues will be addressed.
- Identify the various types of tissue characteristics and relate these to their function.
- 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
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.
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:
- Virtual Microscope - Cells and Tissues
- Integumentary
- Epithelia
- Connective Tissue
- Cartilage
- Bone
- Muscle
- Nervous
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 is extracellular matrix?
- Figure 12.51. Examples of extracellular matrix | MBoC -The Extracellular Matrix of Animals
- Non-cellular material that surrounds cells
- Often secreted/formed by the all or some of the cells embedded in the matrix.
- 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?
