Contains the full lesson along with a supporting toolkit, including teachers’ notes.
The human body is an extremely complex group of organs and tissues, far more complex than the most advanced aircraft. However just like an aircraft, all the systems must work in harmony if we are to survive – the systems must be co-ordinated and controlled. This is achieved by the interaction of two systems: the nervous system and theendocrine system. The nervous system makes very rapid measurements, changes and adjustments. The endocrine system, which consists of all hormone-secreting glands in the body, usually acts more slowly but with longer lasting effects. In this lesson we will look at some hormones that are present in our bodies, and the effect on the body of hormone deficiency.
What is a hormone?
A hormone is a biochemical product that acts as a messenger. Hormones are produced in small quantities by the endocrine glands.
An endocrine gland is a ductless gland that releases a hormone directly into the blood stream in which it travels around the body to exert a specific effect at a particular target site. Hormones are generally classed as peptides such as insulin and ADH [anti-diuretic hormone] or steroids such as testosterone or progesterone.
What are the functions of each of the glands?
The pituitary gland , also known as the master gland, controls all the other glands. It has two lobes; the anterior lobe which releases ADH and prevents excess urine formation, and oxytocinwhich controls birth contractions. The posterior lobe releases a variety of hormones including FSH (Follicle Stimulating Hormone), LH (Luteinising Hormone ), prolactin (released when female is suckled during lactation) and growth hormones. It also produces other hormones that control the adrenal andthyroid glands.