Talk:Foundations - Histology Cells and Tissues

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Expert Tutorial - Histology

  • Note only Cells and Tissues has been done not Skin practical yet.
  • This is your first expert tutorial, here are a few points to remember.
  1. Attend only the tutorial you are assigned too (overcrowded tutorials do not work as well).
  2. It is a tutorial not a lecture, be prepared to ask questions (interact with the expert).
  3. Allow everyone a chance to ask questions.
  4. Posting questions online beforehand will always result in a better answer (and not just beforehand!).
  5. Be specific with your question or identify the concept you do not understand (and not "will this be in the exam").
  6. Take accurate note(s) of the answer. The wrong information returned to your group is worse than no information at all.
  7. Do not wait until the tutorial is finished and everyone is leaving to ask your question (everyone may want to hear the answer and the expert has finished).



Practical Objectives

  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.


Back to - Histology Cells and Tissues


College A & B

A3

  • How is the study of animal histology relevant/useful to the study of human histology? Can it be misleading?
    • Many of the tissues in animal models closely represents that seen in human tissue.
    • Virtual Microscope images are a mix of human and animal tissues. Often human tissue is not available or difficult to prepare.
    • By misleading do you mean different from the human tissue? In most cases not that different. In the practicals it is often explained why human tissue was not available/suitable.
  • How can enzymatic activity, or chemical reactions be studied in histology?
    • Some histological methods (immunohistochemistry) do use the presence of active enzymes on antibodies to produce a coloured precipitate in the tissue where the antibody is binding.
    • Actual tissue enzyme activity is limited by the type of fixation used in preparing the tissue, and usually only seen in fresh tissues.
  • Is the study of histology only limited to a structure/function type analysis?
    • Histology is the "anatomical study of the microscopic structure of tissues" it extends what you are doing in gross anatomy to the tissue/cell level.
    • It is only after you know what the "normal" tissue structure looks like that you can determine "abnormal" (pathological) tissue.


A2

  • How do you identify the different types of leukocyte by their shape?
 
    • You will be doing this identification in later practical classes on blood. At this stage you just need to be aware of the different cells in blood.
  • Could you please explain about the features in this virtual slide that was in Science Practical (Introduction to histology - Cells and tissues)
 http://vslide.med.unsw.edu.au/flashslide.jsp?fn=d48_40xr.fpx&mag=20
    • This slide was for students to work on, the tissue selected contained a range of the different tissues covered in the practical class.
    • It would defeat the purpose of setting "independent learning" exercises to simply provide all the answers.
    • You need to ask specific questions in the expert tutorials.


B2

  • how to differentiate original tissue from the histological slide. i.e. is the slide from a lung/ovary/skin/tracha etcetc
    • By attending the practicals and working through the histological material with the demonstrator/tutor.
  • will we have to know how to recognise and differentiate between the different types of tissues from different parts of the body (and if so, how)?
    • You will need to know the histology of the tissues and virtual slides presented in the practical classes.


A1

  • how does actin and myosin take part in muscle contraction/relaxation
  • How to identify collagen from adipose tissue
    • Stains orange/red in H&E, no nuclei in ECM, adipose usually pale/clear space where lipid droplet was in cytoplasm.
  • How do RBCs function without nucleus?
    • They are packed with haemoglobin, for oxygen/carbon dioxide carrying, before leaving the bone marrow.
    • They survive a limited time and do not divide but are "recycled".

A4

  • What is the most effective way to study histology outside our prac classes?
    • Use you histology textbook, and compare labeled tissues with the unlabelled virtual slide materials until you understand the tissue structure.
    • The virtual slide set is also always available for your revision and you are provided practical class support pages with information that you can use to help with the content.
    • With virtual slides begin at the lowest magnification (to get orientation of the original material, note any changes made in preparation cut edges etc). Then gradually go to higher magnifications and use the small right hand overview image to keep track of your location in the whole tissue.


A5

  • To what level are we expected to be able to identify structures for our exam?
    • Foundations is only an introduction to histology (basic tissues and skin). Many of the tissues will be covered in more detail later in your course.
    • You would be expected to cover the content given in your practical class and in the supporting practical manual notes.
  • What are the different forms of collagen and why do they exist?
    • There are 25 or more collagen types. I have listed the key types and tissue locations below, but you do not need to know this detail for Foundations.
      • Collagen Type I - skin, tendon, vascular, ligature, organs, bone (main component of bone).
      • Collagen Type II - cartilage (main component of cartilage).
      • Collagen Type III - reticular fibers with type I.
      • Collagen Type IV - forms bases of cell basement membrane.

B1

  • why do we form scar tissue?
    • Severe damage to the overlying epithelium leads to replacement with the underlying connective tissue (scar).
  • why doesn't the body just clear out the dead leucocytes and undergo mitosis to replace the damaged cells (aka not forming a scar?)
    • If the underlying epithelia stem cells have been destroyed the epithelium may not be able to be easily replaced.
  • is there a benefit that the body makes it into a scar instead of regular tissue? 
    • Scar maintains the integrity of the barrier.

College C & D

C

  • how to stain cells?
    • answer
  • how much about pictures do we need to know?

C4

  • Please explain tight junctions and gap junctions and any other junctions we need to know
  • Epithelium vs. endothelium vs. mesothelium
  • How do lymphnodes filter?


C5

  • What is the difference between the function of granular neutrophils and non--granular monocytes in phagocytosis?
  • Does plasma as a ground substance have the same compondents as ground substance in other types of connective tissue?
  • What is matrix, what is it composed of, and what is its function? What is the difference between intracellular and extracellular matrix?

D2

  • Is the formation of adipose tissue controlled by genetics, and if so how do other factors, such as lifestyle, affect the amount of adipose tissue one has?
  • Why is there different shaped cells and layer structures in epithelial tissue eg/squamous, stratified etc? Is there a functional difference between shapes and layer organisations?
  • How do red blood cells operate without a nucleus and organelle?  Do they produce their own haemoglobin or is there a set amount when they are produced in the bone marrow?
  • How does myelin act to speed up the transmission of signals, and why do some nerve fibers not have this myelin sheath?

D3

  • How do we identify pseudostratified cells?
  • What exactly is collagen and how can we identify it in slides?
  • How do we tell the difference between glands and ducts?
  • Why do different blood cells have different shaped nuclei?
  • How many different types of tissue fall underneath the term collagen and what are these?


D5

  • What other stains are there? What are the characteristics of each one?
  • Clarification of staining process for gram positive and negative.
  • How does  crystal violet and iodine enter the peptidoglycan in gram positive if they can't escape?
  • What is the difference between the function of granular neutrophil and non-granular monocytes?

Histology Stains

You do not need to know details about histological staining techniques, but knowing what a stain will do will help you understand the slides.

Eosin

  • Stains cytoplasm pink to red; red blood cells are also bright red.
  • Common counterstain to hematoxylin.
  • Stain intensity varies with the formula as well as the fixative.

Hematoxylin

  • Stains nuclei blue to dark-blue.
  • Stains the matrix of hyaline cartilage, myxomatous, and mucoid material pale blue.
  • Stains myelin weakly but is not noticeable if combined with eosin stain.

Silver Impregnation

  • Stains collagen grey/brown.
  • Stains reticular fibres (type III collagen) black.