The endocrine system, specifically hormones, controls hair growth.
How Hormones Regulate Hair Growth
Hormones play a pivotal role in the development and growth of hair. According to the provided reference, androgens are key regulators of human hair growth. Other hormones also contribute, particularly in mammals, including:
- Melatonin
- Prolactin
- Melanocyte-stimulating hormone (MSH)
- Oestrogens
These hormones influence different aspects of hair growth, such as:
- Hair follicle development: They determine the structure and size of the hair follicles.
- Hair cycle phases: They control the growth, rest, and shedding phases of hair.
- Hair type: They contribute to the characteristics of hair, such as thickness and length.
- Hair distribution: Hormones affect hair growth patterns across different parts of the body.
Androgens: Key Regulators of Hair Growth
Androgens, such as testosterone and dihydrotestosterone (DHT), are critical in hair growth. They cause:
- Male pattern baldness: High levels of DHT can shrink hair follicles on the scalp, leading to hair loss.
- Body hair growth: Androgens stimulate hair growth in areas like the face, chest, and back.
- Pubic hair development: Androgens are responsible for the development of pubic hair during puberty.
Other Hormones Involved
While androgens are the primary regulators of hair growth, other hormones also play a part:
- Melatonin: This hormone, known for regulating sleep cycles, can also influence hair growth cycles.
- Prolactin: Produced by the pituitary gland, prolactin is associated with lactation, but it also plays a part in hair growth.
- MSH: This hormone can affect hair pigmentation and potentially influence hair follicle activity.
- Oestrogens: These hormones contribute to hair growth, particularly in females. Their levels can impact hair thickness and growth cycles.
Summary
In summary, while multiple hormones influence hair growth, androgens are the primary regulators in humans. The interplay of these hormones ensures complex patterns of hair growth and development across different parts of the body.
