Identify:

1. Macroscopic

   Hold the slide against a white background and look at it with the naked eye, or at very low magnification. Orientate yourself with regard to the three visible primary layers of the skin of the palm, as well as the subcutaneous tissue. Identify the three coloured layers seen in the section:

• The different textures and intensity of stained layers of thick skin.

• A dark pink to red scalloped area - the epidermis.

• A central light pink area - the dermis.

• A thick very light pink area - the hypodermis.

Microscopic

• Lumen of the blood vessel

The blood vessels can be found under low magnification in the dermis.

• Endothelial cells against the lumen

• Nuclei of the endothelial cells

• Cytoplasm

• Layers of the blood vessel wall

• The different layers of the epithelium which form the epidermis

• The shape of the cells in the different layers

• Fat cells

• Connective tissue septa.

• Adipose tissue

• Pacinian corpuscles

  Pacinian corpuscles are found in the subcutaneous fat tissue.

• The subcutaneous tissue

• Sweat glands

Draw and annotate:

The layers of the skin, including the subcutaneous tissue and sweat glands.

A line diagram of the bloodvessel and endothelial cells.

A few epithelial cells of each layer of the epithelium to show the different cell shapes.

A line diagram of a few lobules of fatty tissue. In one of the lobules draw fat cells as well as the surrounding connective tissue septa.

A Pacinian corpuscle.

1. What is characteristic of the endothelial cells?
2. What is characteristic of the cytoplasm of these endothelial cells? And the nuclei?
3. What is sometimes seen in the lumen?
4. How many cell layers are present in the epithelium of skin?
5. How does the shape of the cells in each layer of the epithelium of skin change?
6. How does the junction between the epithelium of skin and the underlying support structures (connective tissue) appear?
7. How does the appearance of these fat cells differ from those that were stained with Sudan IV? [Compare Slide 5: Fat cells]
8. Describe the Pacinian corpuscle.
9. What is the capsule of a Pacinian corpuscle made from?
10. What are the different layers of the dermis, and what type of support tissue is found here?
11. What is characteristic of the subcutis (hypodermis)?
12. What is characteristic of the ducts of the sweat glands?
13. How does one distinguish between the secretory part and the tubular part of sweat glands?

Microscope