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Circulation: Blood- and Lymphatic Vessels

  

Cardiovascular system

The goal of this topic is to examine and understand the structure of the heart, blood vessels and the lymphatic vessels. You should aim to understand how the structure of blood vessels change from large arteries to the level of capillaries and back to large veins. At each level, the composition of component layers are closely related and adapted to the function at that level. The same principle of relationship between the layer structure and function is seen in the respiratory and digestive systems. The cells in blood are covered in Blood. You should also review Contractile cells. Study each of the given types of vessel using the following points:
  1. Structure and size of lumen.
  2. Presence or absence of the three luminal layers.
  3. The thickness of the layers in the vessel.
  4. The thickness of the tissue between the different layers.
  5. The different types of tissue found in each layer.
  6. The presence or absence of vasa vasorum.

You should be able to:

  1. Describe the general anatomy of the cardiovascular system.
  2. Describe how the histological morphology facilitate the functioning of the cardiovascular system.
  3. Describe the structure and function of each of the parts of the cardiovascular system.
  4. Describe the generic structure seen in blood and lymph vessels.
  5. Describe the specific structure seen in each part of the cardiovascular system.
  6. Correlate the structural specialisations in each part of the cardiovascular system with the function of that part.
  7. Identify and describe the various types of arteries, veins, arterioles, capillaries and venules.
  8. Compare arteries, veins, arterioles, capillaries and venules.
  9. Compare blood and lymphatic vessels.
  10. Explain the structure, function and distribution of valves in the cardiovascular system.
  11. Give examples of each of the types of vessels found in the cardiovascular system.
  12. Describe the various portal systems and their relevant histology.
  13. Identify, describe and compare the various contractile elements found in the cardiovascular system and the rest of the body
.

Slides for this week

For each slide, complete the work as listed below. Completing the whole slide will assist you in understanding and retention. For each slide, allocate an A3 spread in your workbook. Remember to add the slide and its page number to the index in the front of the book.

Tasks

Study each of the slides, using the guidelines below. Select and compare different types of staining (H/E and R/F) where available and as appropriate. Follow the steps below. DO NOT JUMP AROUND or SKIP STEPS! Use the following points and compile a table for each type of vessel:
  • Structure and size of the lumen.
  • Presence or absence of the three luminal layers.
  • The thickness of the layers in the vessel.
  • The thickness of the subdivision in each layer.
  • The presence or absence of vasa vasorum.
Slide name Slide number Stain
Vessels
Muscular artery and vein 69 H/E
Muscular artery and vein 70 R/F
Elastic artery 67 H/E
Elastic artery 49 R/F
Large vein 92 H/E
Large vein 109 R/F
Ductus thoracicus 75 H/E
Ductus thoracicus 65 R/F
Accessory structure
Valve 47 Masson’s trichrome
Cardiac muscle
Heart muscle (longitudinal section) 20 H/E
Heart muscle (cross section) 77 H/E
Heart muscle 86 Y/H

Calibration

  • Tabulate the differences between elastic and muscular arteries and arterioles.
  • Name the 3 types of capillaries.
  • Tabulate the differences between small, medium and large veins.
  • Name the 3 layers of the heart wall.
  • Explain the conducting system of the heart.
  • How does some common diseases affect the structures of the cardiovascular system?
  • What are the two main component parts of the circulatory system?
  • Describe the maintenance and regulation of blood pressure based on the histological morphology of the circulation system.
  • On a histological section, what can be used to initially differentiate between arteries and veins of all sizes?

  • Make a schematic diagram, showing the regions and major structural features of blood vessels in each region. Indicate the function of each region.

    You should have on your drawing the following items:

    • Macrovascular and microvascular system.
    • Heart, elastic arteries, muscular arteries, arterioles, capillaries, cells, venules, valve, vein.
    • Histological features should include: tunica intima, media and adventitia, smooth muscle cells, pre-capillary sphincters, pericytes, endothelial cells, basal lamina, capillaries.

  • What is the function of elastic arteries?
  • On a histological section, what can be used to initially differentiate between arteries and veins of all sizes?
  • What is the function of lymphatic vessels?
  • What are end-arteries?
  • How are the central artery of the retina, coronary arteries, segmental arteries of the kidneys and arteries entering the brain different from arteries in the rest of the body?
  • How are the central artery of the retina, coronary arteries, segmental arteries of the kidneys and arteries entering the brain similar?
  • What happens when end-arteries are occluded?
  • What is a portal system? Give an example of portal systems.
  • Compare the structure of the vena cava with elastic arteries.
  • Name 4 characteristics that is used as diagnostic of muscular arteries.
  • What morphological feature is characteristic of medium veins?
  • What mechanism facilitate return of blood to the heart?
  • Describe the general structure of veins in comparison to arteries.
  • What mechanism drives lymphatic flow?
  • Describe how the histological morphology facilitate the functioning of the cardiovascular system.
  • Describe how the generic structure is modified for different functions in the different parts of the cardiovascular system.
  • Identify and explain the differences between blood vessels and lymphatic vessels.
  • Describe the flow of blood to and from the heart from and to the extremities.
  • Compare arteries, veins, arterioles, capillaries and venules in terms of structure and function.
  • Explain the structure, function and distribution of valves in the cardiovascular system.
  • Give examples of each of the types of vessels found in the cardiovascular sy•stem.
  • Describe the various portal systems and their relevant histology.
  • Identify, describe and compare the various contractile elements found in the cardiovascular system and the rest of the body.
  • Describe the flow of blood to and from the heart from and to the extremities.
 
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