Main Takeaways
1. Stem cells give rise to the hairs on our head and body, with a population of stem cells residing in a pocket at the base of every hair root.
2. The sebaceous gland beside each hair root produces sebum, an oil that acts as a strong antibacterial and hydrates the hair.
3. The erector pili muscle lies below the bulb and causes goosebumps and makes hairs stand up.
4. Capillaries deliver oxygen and nutrients to support stem cells and melanocytes, which gives hair color.
5. Hair is made up of keratin, and hair loss can cause significant anxiety and depression.
6. The growth of hair has three phases: anagen, catagen, and telogen.
7. Dihydrotestosterone (DHT) can cause hair loss by changing the bulb region where stem cells reside.
8. Hair growth accelerators include Minoxidil, Tadalafil, Platelet-rich plasma (PRP) injections, microneedling, and Botox.
9. Insulin growth factor-1 (IGF1) and cyclic AMP extend the anagen phase, while phosphodiesterase (PDE) and TGF-beta-2 shorten it.
10. Testosterone and its derivative can cause androgen-related alopecia, which is the most common form of hair loss.