skin
10 questions tagged skin — spanning every one of the seven Ws.
Why do we get stretch marks?
Stretch marks form when skin stretches quickly and the supporting collagen and elastin fibres in the dermis tear.
Why do our hands get wrinkly after being in water?
The wrinkling is an active response controlled by nerves, not just the skin soaking up water. Blood vessels in the fingertips constrict, which creates the familiar ridges.
What is the subcutaneous fat layer?
The subcutaneous fat layer is the fatty tissue beneath the skin. It stores energy, insulates the body, and cushions underlying structures.
What is the dermis?
The dermis is the middle layer of the skin that contains blood vessels, nerves, sweat glands, and hair follicles. It supports the skin’s strength and sensation.
What is the stratum corneum?
The stratum corneum is the outermost layer of the epidermis made of dead, flattened skin cells. It forms a protective barrier against water loss and environmental damage.
How does the skin heal after a cut?
Skin healing happens in stages: clotting, inflammation, new tissue growth, and remodeling. Small cuts often seal in days, while deeper wounds can take weeks or longer.
How do fingerprints form before birth?
Fingerprints form in the womb as skin grows, folds, and is shaped by genetics and tiny physical pressures. The pattern is set before birth and remains mostly unchanged for life.
Where in the skin is melanin produced?
Melanin is produced by melanocytes in the epidermis, mainly in the basal layer. The pigment then helps protect skin cells from ultraviolet radiation.
Which part of the human body has the thickest skin?
The soles of the feet have some of the thickest skin on the human body. This helps them handle constant pressure and friction.
Which part of the human body has the thinnest skin?
The eyelids have the thinnest skin in the human body. It is very thin so the eyes can move and blink easily.