In this lecture, Professor Diamond explores the endocrine system in depth, covering the structure and function of the pineal gland, ovary, testes, thyroid, parathyroid, adrenal gland, and pituitary gland.  She first mentions the pineal gland and its regulation of the circadian rhythm. She briefly discusses the ovary and testes and their role in hormone production before moving on to discuss the thyroid. She discusses the shape, location, and structure of the thyroid and the role of the T3 hormone in determining metabolic rate and development of nervous system. She notes that the pituitary gland affects thyroid activity through thyroid stimulating hormone (TSH). She touches on disorders caused by thyroid overdevelopment and underdevelopment. She discusses the role of the parathyroid in regulating calcium levels. Professor Diamond then introduces the adrenal gland and discusses the hormones produced by the gland, including epinephrine and norepinephrine. Finally, she reviews the pituitary gland in greater depth, describing the effects that its hormones produce in the body before concluding by showing several slides of the major endocrine glands.