Hormones are chemical messengers regulating cell functions.

• 24.1 The “cuddle” chemical: oxytocin increases trust and enhances pair bonding.
• 24.2 Hormones travel through the circulatory system to influence cells elsewhere in the body.
• 23.3 Hormones can regulate target tissues in different ways.

Hormones are produced in glands throughout the body.

• 24.4 The hypothalamus controls secretions of the pituitary.
• 24.5 Other endocrine glands also produce and secrete hormones.

Hormones influence nearly every facet of an organism.

• 24.6 Hormones can affect physique and physical performance.
• 24.7 Hormones can affect mood.
• 24.8 Hormones can affect behavior.
• 24.9 Hormones can affect cognitive performance.
• 24.10 Hormones can affect health and longevity.

Environmental contaminants can disrupt normal hormone functioning.

• 24.11 Chemicals in the environment can mimic or block hormones, with disastrous results.
• 24.12 This is how we do it: Would you like your receipt? (Maybe not.)