Histology of the Skin

Hello all, I've tried to come up with some slides and pictures which can help you with tommorow's practical session. Here are a few compilations of slides which I compiled from some websites across the internet. Most of the explanation are of my own so forgive me if it's not really accurate. Enjoy!

CLICK ON THE PICTURES TO ENLARGE AND TO GET A BETTER VIEW.
(Sorry, the pictures look a little off coz its too big)

THICK SKIN The following picture shows the histology slide for thick skin. Things to note for is the thickened keratinized layer or the stratum corneum.

Here is a close up of that layer ( thick purple layer as shown below)

Here shows another view of the whole layer of thick skin.

THIN SKIN

Here is a picture of the thin skin: (Notice the much thinner stratum corneum layer as compared to the thick skin)

COMPARISON OF THICK AND THIN SKIN

Here is a side by side comparison of the thick and thin skin:

This plate shows the structural variation of the epidermis in different parts of the body.

The epidermis in all three areas is keratinized stratified squamous epithelium. The thickness varies from one site to the other. Note the marked thickness of the epidermis in C (palm). The epidermis of palms of the hands and soles of the feet is the thickest in the body. In these regions only four layers of the epidermis are well delineated.

SKIN APPENDAGES

Here are the labelled diagrams you can use for the pratical.

MELANOCYTES AND MELANOMA

Here is what melanocytes would look like:

(Notice the brown area? Those are the due to the production of melanin)

As you can see in this picture, the epidermal layer is much much more thicker in melanoma as compared to the normal skin. (Epidermal layer is the one in darker purple)

A closer view at 20x shows disorganisation of the cells. Not sure how else to describe it.

PSORIASIS

Four distinct pathological alterations characterise this disorder:

•		Inflammation.
•		Hyperproliferation of the epidermis
•		Altered maturation of the epidermis (resulting in scaling)
•		Vascular alterations (which add to redness).

Histology of psoriasis

1. Marked hyperkeratosis with parakeratosis (abnormal maturation)

2. Loss of granular layer

3. Epidermal acathosis and elongation of rete ridges (reflecting hyperproliferative state)

4. Vascular dilatation (these vessels are abnormal as well). Generalised inflammation can also be seen, with T-lymphocytes in the dermis and epidermis.

   For more info on this : Visit these websites!
   http://www.dermamed.com/tech_docs/psoriasis/psoriasis_lit.asp http://www.dermnet.com/thumbnailIndex.cfm?moduleID=15&moduleGroupID=462&groupIndex=0&numcols=0