What are hormones for?

Hormones are chemical messengers produced in glands and have various significant effects on both the brain and body. They are released from one area and travel to influence different organs and tissues. Hormones play a role in many processes, including development, growth, metabolism, and puberty.

Fast and Slow Effects: Hormones can act rapidly or slowly. For example, adrenaline can quickly increase heart rate, while cortisol can have both swift and slower effects. On the other hand, sex steroid hormones, like testosterone and estrogen, have quick signaling effects and long-lasting impact by controlling gene expression and altering cell functions 1.

Development: Hormones are crucial throughout life, from the womb to adulthood, and influence brain and body development continuously. During puberty, hormones like testosterone and estrogen trigger significant physical and psychological transformations through changes in gene expression 2.

Metabolism: Hormones like thyroid hormone and growth hormone play a substantial role in regulating metabolism, which includes energy use, body tissue growth, and repair. They support maintaining cognitive function, tissue repair after injuries, and possibly offsetting diseases like dementia 3.

Genetic Expression: Hormones can penetrate cells, turning on or off specific genes, shaping how cells develop and function. The ability to alter gene expression explains the dramatic physical changes during puberty, such as voice deepening, muscle growth, and the development of secondary sexual characteristics 4.

Puberty and Fertility: During puberty, hormones like luteinizing hormone (LH) and follicle-stimulating hormone (FSH) regulate the maturation of reproductive organs and gametes, thus playing a detailed role in fertility for both males and females 2.

Hormones are essential because they help orchestrate complex physiological processes, impact development and function across the lifespan, and maintain homeostasis within the body.