Today’s AIM: Why do we have raging hormones? DO NOW: Using your notes from yesterday, discuss the nervous system. In your response, be sure to: • State the function of the nervous system • Identify the main organs and tissues of the nervous system • Explain the role of neurons and neurotransmitters in cellular communication • Identify the part of the receiving cell where neurotransmitters are sent ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ The Endocrine system has endocrine glands all over the body that release chemical signals called hormones into the bloodstream. These hormones are sent to the receptor molecules of the targeted cells. The Endocrine System http://www.youtube.com/watch?v=8fh2HmdxQjQ& feature=related Endocrine System Action Hormones are controlled by feedback from your body! Hormones help maintain homeostasis! Do hormones make us feel hungry? In 2003, scientists made a breakthrough discovery when researching the causes of hunger in humans. For years, scientists had puzzled over why we feel hungry when we are low on food – why our stomach starts producing stomach acid, our mouths start producing saliva, and our brains seem to only focus on food – and yet feel quickly full as soon as we have eaten. After years of searching, a team of scientists at the University of Washington in Seattle discovered a pair of hormones, named “Ghrelin” and “PYY” which work together to determine how hungry we feel. Ghrelin appears to make individuals feel hungry – causing many of the symptoms we connect with needing food (a ‘growling’ stomach, increased saliva production, dizziness and feeling ill). PYY, on the other hand, appears to make individuals feel full – making us realize we’ve eaten enough. When an individual is low on food, endocrine glands near the stomach start producing Ghrelin in large amounts. After a person has eaten a lot of food, Ghrelin-making glands shut off, and PYY-making glands become activated. After digestion has occurred and the stomach is empty, PYY glands shut off, and Ghrelin glands activate again. Do hormones make us feel hungry? In 2003, scientists made a breakthrough discovery when researching the causes of hunger in humans. For years, scientists had puzzled over why we feel hungry when we are low on food – why our stomach starts producing stomach acid, our mouths start producing saliva, and our brains seem to only focus on food – and yet feel quickly full as soon as we have eaten. After years of searching, a team of scientists at the University of Washington in Seattle discovered a pair of hormones, named “Ghrelin” and “PYY” which work together to determine how hungry we feel. Ghrelin appears to make individuals feel hungry – causing many of the symptoms we connect with needing food (a ‘growling’ stomach, increased saliva production, dizziness and feeling ill). PYY, on the other hand, appears to make individuals feel full – making us realize we’ve eaten enough. When an individual is low on food, endocrine glands near the stomach start producing Ghrelin in large amounts. After a person has eaten a lot of food, Ghrelin-making glands shut off, and PYYmaking glands become activated. After digestion has occurred and the stomach is empty, PYY glands shut off, and Ghrelin glands activate again. Ghrelin and PYY are what type of chemical signals? ____________________________________________ Identify the system that produces these signals. ________________________________________________ According to the passage above, Ghrelin and PYY work together in a (1) Being connected by similar neurons (3) Being part of a feedback loop based on eating (2) Using the same endocrine glands (4) Causing the same effects in the body Independent Practice