Structure and function of the dermis in general Structure; deep part of skin; connective tissue composed of two layers function; is responsible for the structural strength and flexibility of the skin; the epidermis exchanges gases nutrients and waste products with blood vessels in the dermis
My new answer: Usain Bolt acheived a top speed of 27.28 mph or 43.90 kph in travellng the 2 fastest consecutive 60-70 & 70-80, 10m splits ever of .82 seconds. We'll leave out 4x100m splits as I don't have them for Team Jamaica's WR from Beijing.
The limit to how fast a human can run is 9.48 seconds for the 100-meter race, 0.10 seconds faster than Usain Bolt's current world record, according to Stanford biologist Mark Denny. That is, if you are talking about natural human beings.