- Keratinocyte moves up through the layers of the skin it changes (differentiates)
- Corneocyte has the ability to reflect light
Consisting of a single row of epithelium cells, which constantly divide to produce new cells.
Connects Dermis to Epidermis
Keratinocytes divide to produce new cells
1 in 10 cells is a melanocyte
The lifespan of a Keratinocyte from mitosis to arriving in the Stratum Corneum is about 10-15days
These threads are part of the desmosomes, and play a major role epidermal strength and cell adhesion.
Melanocytes synthesise melanin and transfer them to neighbouring keratinocytes at this layer
The melanosome (now known as the pigment melanin) becomes part of the keratinocyte.
It will settle over the nucleus area of the keratinocytes (cell protection),
UV exposure causes an increase in the number of keratinocytes and an increase in the number of melanosomes increasing melanin transfer to keratinocytes
Keratin Granules – Keratin Protein
Lipids pass through membrane to form NMF
NMF components absorb water from the atmosphere and combine it with their own water content.
NMF components are water soluble, they are easily leached from the cells with water contact – which is why repeated contact with water actually makes the skin drier. The lipid layer surrounding the corneocyte helps seal the corneocyte to prevent loss of NMF.
- Cornedesomes – bridge corneocytes
- Free Water controls dissolution of corneodesmosomes
- Causes Excess Keratinisation and blocked pilo sebaceous duct
- Friction and chafing and UVR causes excess keratinisation
- more keratinocytes will be produced to pick up the melanosomes
The tags form a single or multiple distribution being made up of loose fibrous tissue. The colour is often changed and they can be hyper pigmented making them more obvious. Skin tags or papillomas are derived from epithelial cells. They grow like a plum on a plum tree. They often appear with a neck like a mushroom and vary in size from a tiny speck, smaller than a grain of uncooked rice to the size of a large pea or larger. Viral in nature and whilst not highly infectious, they do seem to spread on individuals and should be considered as contagious. Commonly found in areas of friction such at the axillae and under the breasts.