In the last sub-unit of unit 6 we are going to explore the content of:

• Insulin and glucagon are secreted by β and α cells of the pancreas respectively to control blood glucose concentration


• Thyroxin is secreted by the thyroid gland to regulate the metabolic rate and help control body temperature


• Leptin is secreted by cells in adipose tissue and act on the hypothalamus of the brain to inhibit appetite


• Melatonin is secreted by the pineal gland to control circadian rhythms


• A gene on the Y chromosome causes embryonic gonads to develop as testes and secrete testosterone