For the same reason you have any other physical trait. Hair color, height, ear shape, nose anything, it's just the way you are put together.
The hair root is in the skin of your scalp. The hair shaft is the rest of the hair that you see.
The cortex layer of the hair shaft is made of cortical cells. It is the middle layer of the hair shaft and provides strength, elasticity, and color to the hair.
the purpose of the hair shaft is to protect and moisturize the scalp.
If you have a flat shaft then then you have curly hair. If you have straight hair you have an oval shaft. It always depends on what type of shaft you have. It also depends if you have wavy hair or not.
hair shaft
The structure of a hair shaft is where it grows and goes through the three different phases
Hair Shaft
hair shaft
Hair Shaft
The bulk of the hair shaft is made of a protein called keratin. Keratin provides strength, structure, and elasticity to the hair, making it resilient to external factors like heat and chemicals.
Cuticle scales are formed from dead cells on the hair cuticle, which is the outer layer of the hair shaft. The scales give the hair shaft strength.
Hair shaft