nails are non living but then how they grow?
Answers
Nails and hair *not* “basically dead cells” they are part of an organized unit of tissue which contains living and non-living components. Take a very close look at this illustration of a hair as it exists in a tissue…
The top part is a close-up view of a hair that might be seen with a magnifying glass, but the bottom detailed part is a microsopic view only discernable with a microscope. In the bottom illustration, you can see layers and layers of individual cells… maybe 1000+ cells in this picture. The papilla, and root sheaths are all living. These cells proliferate and push up the daughter cells inward and upward towards the cortex and medulla zones. As the cells are pushed together, two things happen (1) they start synthesizing *a lot* of keratin protein and (2) they start to squeeze out their cytoplasm. By the time they are in the cortex/medulla they are not really living cells any more but inert bags of keratin protein. Down at the base of the the hair follicle, as the living cells continue to do their thing, more and more keratin-filled cellular reminats are pushed upwards and the hair shaft increases in length — it is said to “grow.”
(“Grow” is not a very good word because it can mean several things. It can mean that something gets physically larger - “hypertophy.” It can mean that you get more and more numbers of something - “proliferation.” The above description involves both hypertrophy of the hair shaft and proliferation of the cells at the base of the shaft).
This is how hair works… I invite you to look up how nails work. It’s the same concept of living and non-living elements of an organized tissue element…
