TOUGH SOLES

With feet like this, who needs boot leather? Let's see if there is anything special about tough soles, or just skin for that matter.

The largest organ of your body, your skin represents ~16% of your bodyweight and is made up of 3 zones of layers called: epidermis, dermis and hypodermis. 
The skin interfaces between you and your environment: 
·         protecting against pathogens & water loss
·         synthesising Vitamin D
·         regulating body temperature
·         detecting pain, sensation, pressure, & temperature
·         waterproofing you
·         insulating & cushioning you
·         excreting waste
·         and if that’s not enough - it repairs itself!  (We forget how clever that is)

Your palms and soles lack sebaceous glands, hair and full pigmentation, but have a high concentration of nerve endings.  They also provide unique fingerprints and footprints of you for the police!

Now, each of your feet have 28 bones, 107 ligaments, 33 joints and 20 muscles!  Surely this intricate structure deserves some protection without relying on manufactured shoes.  No problem!  A 27 day process called keratinisation transfers a protein called keratin to saturate dead skin cells in the most superficial layer called the stratum corneum. This results in the skin of the sole becoming up to 15 times thicker than facial skin and 1.5mm thick - depending on the roughness of the terrain walked on!

Surely there is more to this than just good luck for millions of people without footwear?

 

Acknowledgements: anatomyatlases.org                                                        Photo credit: lurvely.com