How does the skin work?

Our skin isn't just a shell for the body – it's a living organ that performs lots of vital functions.

Transcript

00:00 We have a lot to thank our skin for.

00:03 It protects us from UV rays, cools our bodies in the heat and keeps us warm in the cold.

00:10 It forms a barrier against intruders like viruses and bacteria.

00:16 And unlike this rubber duck, it can regenerate itself if it gets damaged.

00:21 It's because our skin is not just a shell, but a living organ.

00:29 Some cells constantly produce new skin cells, while old ones die and shed away.

00:34 The top layer of skin, called the epidermis, renews itself completely about once a month.

00:40 The skin has a complicated relationship with the sun.

00:44 On the one hand, it's dependent on the sun's help, for example in the production of vitamin D3.

00:50 On the other hand, sun rays, especially in the ultraviolet spectrum,

00:56 can lead to inflammation of the skin cells and damage their genetic material.

01:00 Mutations of stem cells in the lower layer of the epidermis are a common cause of skin cancer.

01:07 Special cells called melanocytes offer protection against this.

01:16 They produce melanins, pigments that absorb and scatter UV rays and thereby protect the cells.

01:23 The dark eumelanin pigment is particularly effective.

01:26 The more of it the skin produces, the darker it looks.

01:29 Beneath the epidermis is the dermis.

01:32 This is where you find the nerve endings that register and transmit touch or pain.

01:37 Blood and lymph vessels that supply skin cells with nutrients and bring in immune cells to fight invaders.

01:45 Hair follicles that constantly produce new hair.

01:51 Sebaceous glands whose oily secretion forms a protective film and keeps the skin supple.

01:56 And sweat glands.

01:58 Some of them secrete smells, but above all they cool the body by producing sweat that evaporates from the surface of the skin.

02:07 The fatty tissue beneath the dermis, on the other hand, keeps us warm.

02:13 And energy is stored here in the fat cells, sometimes more than we'd like.

02:20 The skin is our largest and heaviest organ, and yet it's surprisingly elastic.

02:25 After all, the body it surrounds is constantly changing.

02:29 [Music]