HORMONE Is a chemical substance, produced by a gland, carried by the blood, which alters the activity of one or more specific target organs and is then destroyed by the liver
Adrenaline The “fightorfright” hormone.
Itisreleased in stress-fulsituations
Alltheeffectsmakeus more abletoreactquickly and vigorously in dangeroussituationsthatmightrequireustorunawayorput up a struggle.
12 The glucose concentration in the blood is controlled by the PANCREAS. The pancreas contains cells which produce digestive enzymes but it also contains cells (alpha and beta cells) which produce the hormones insulin and glucagon -If the glucose concentration rises, the beta cells release insulin. -If the glucose concentration falls, the alpha cells release glucagon. -Insulin stimulates the liver and muscles to remove excess glucose from the blood and store it as glycogen -Glucagon stimulates the liver to convert its stored glycogen intoglucose which is then released into the bloodstream. In this way, the concentration of glucose in the blood is kept within narrow limits
NEGATIVE FEEDBACK Is a system of control in which the outgoing impulses counteract the effects which produced the incoming impulses.