IGNIS | Page 20

The Endocrine System The endocrine system consists of all of the glands inside the body that secrete around 50 hormones into the blood. The glands are controlled by the nervous system as well as by chemical receptors in the blood and other hormones secreted from other glands! These hormones activate and stimulate different organs and control metabolism, reproduction and development. The chemicals control lots of the body’s processes. The Hypothalamus Adrenal Glands The hypothalamus is part of the brain and it serves many functions in the nervous system, as well as controlling the endocrine system through the pituitary gland. It has special cells called neurosecretory cells which are neurons that secrete hormones. The hormones it releases affect the pituitary gland. The hormone adrenaline is what wakes your body up when you feel at risk or before you kiss someone. This is produced by your adrenal glands, which are found by your kidneys. It increases your cardiac rhythm, the pressure in your arteries and the flow of blood to your muscles. The Pituitary Gland The pituitary gland is also known as the master gland as it controls the rest of the endocrine glands. It has an anterior lobe and a posterior lobe. It is a small pea-sized lump of tissue connected to the hypothalamus. There are lots of blood vessels surrounding it to carry the hormones that it releases through the body. Your pituitary gland is also associated with psychological behaviours such as affection. The Pineal Gland This is a small mass of glandular tissue found below the brain. It helps to regulate our sleep-wake cycle, known as the circadian rhythm, by producing melatonin. The pineal gland is told not to release melatonin when the photoreceptors in your retina are stimulated – when they receive light. When you are in low light or darkness, the pineal gland produces melatonin, causing you to feel drowsy. 20 IGNIS The Pancreas The pancreas increases the glucose level in your blood before you kiss someone. It is in charge of the two hormones that control your blood sugar level – glycogen and insulin. Glycogen increases the blood sugar levels in the bloodstream and insulin lowers blood glucose levels after a meal. Pheromones These are chemical substances released by the glands in your skin that are related to sexual attraction. They transmit sensations of excitation, attraction and also, unfortunately, rejection. Oxytocin Oxytocin is the hormone that influences basic body functions – birth, breast-feeding and being in love. It is commonly associated with affection and tenderness, and it stimulates the formation of bonds of affection.