14.5 Growth Hormones Growth is a complex process and requires the coordination of several hormones of which the main one is growth hormone. It is produced by the pituitary gland and acts on the liver, stimulating it to produce another hormone. It is this second hormone, which directly affects the growth of bone and muscle. Growth hormone also helps to control the body’s use of proteins, carbohydrates and fats. The lack of growth hormone can slow bodily development. 14.6 Adrenaline Adrenaline (BAN) or epinephrine (INN) is a hormone and a neurotransmitter. This hormone is produced by the adrenal glands, which lie at the tops of the kidneys. Normally a small amount of adrenaline is produced and this helps to maintain normal blood pressure. In situations of stress or excitement, however, a large amount of adrenaline is produced very quickly and this has a dramatic effect on the body. That is why adrenaline is sometimes called the ‘emergency hormone’. It prepares the body for a fight or flight response. In stressful situations, your body produces adrenaline and prepares itself for a physical response. Functions of Adrenaline: • raises blood sugar levels by stimulating the liver to change glycogen into glucose • causes fatty tissue to release fat into the blood • increases the heart rate • increases blood flow to the muscles • reduces blood flow to the skin and the intestines • widens the bronchioles • dilates the pupils All of this means the body is ready for action. Unfortunately, in today’s world, people suffer from stress and produce adrenaline in situations where no physical activity is required. A certain amount of stress is good and keeps our bodies working properly but repeated and prolonged episodes of stress can cause health problems such as sleepless nights, high blood pressure, and digestive problems. Epinephrine is used as a drug in cardiac arrest and other cardiac disrhythmias, as a vasoconstrictor in anaphylactic shock and sepsis, and as a bronchodilator in acute bronchial asthma. Allergy patients undergoing immunotherapy can get an epinephrine rinse before their allergen extract is administered. 14.7 ADH (Anti-Diuretic Hormone) The amount of water in the blood must be kept more or less the same all the time so there has to be a balance between the amount of water taken in the diet and the amount lost by the body in sweating, evaporation, faeces, and urine. This is achieved by the action of the hormone ADH (Anti-Diuretic Hormone). The hypothalamus detects whether there is or not enough water in the blood. Then it sends a message to the pituitary gland, which releases ADH. The kidneys save more water, so that the urine becomes less in volume and more concentrated. The level of water in the blood can then begin to rise as water is ingested and produced by the process of respiration. If there is too high a level of water in the blood, production of ADH will stop. The kidneys will not save as much water and the urine becomes dilute and of greater volume. The level of water in the blood then begins to fall towards the ideal level. 14.8 Endorphin Endorphins are endogenous opiod biochemical compounds. They are peptides produced by the pituitary gland and the hypothalamus in vertebrates, and they resemble the opiates in their abilities
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