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Communication by hormones in mammals key facts ► Hormones - peptides, proteins, steroids – small molecules = first messenger ► Endocrine gland – secretes hormones into blood plasma e.g. pancreas + insulin + glucagon ► Exocrine gland – secretes into duct / tube e.g. pancreas and digestive enzymes ► Target cells / tissues for protein or peptide hormones have receptors with complementary shapes on cell membranes ► Cyclic AMP (cAMP) = second messenger inside cell ► http://highered.mcgraw-hill.com/sites/0072507470/student_view0/chapter17/animation__second_messenger__camp.html http://highered.mcgraw-hill.com/sites/0072507470/student_view0/chapter17/animation__second_messenger__camp.html ► http://www.celanphy.science.ru.nl/Bruce%20web/Flash%20Movies.htm http://www.celanphy.science.ru.nl/Bruce%20web/Flash%20Movies.htm
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http://highered.mcgraw- hill.com/sites/0072507470/student_view0/chapter17/anim ation__second_messenger__camp.html http://highered.mcgraw- hill.com/sites/0072507470/student_view0/chapter17/anim ation__second_messenger__camp.html
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First and second messengers and amplification ► http://bcs.whfreeman.com/thelifewire/conte nt/chp15/15020.html http://bcs.whfreeman.com/thelifewire/conte nt/chp15/15020.html http://bcs.whfreeman.com/thelifewire/conte nt/chp15/15020.html ► http://www.sinauer.com/cooper/4e/animati ons1503.html http://www.sinauer.com/cooper/4e/animati ons1503.html http://www.sinauer.com/cooper/4e/animati ons1503.html
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Responses to adrenalin hormones
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Brain warm up ► use plasticene and other materials to explain what is meant by the first and second messenger in communication by hormones such as adrenaline ► suggest how a medical drug could be used to prevent the changes in the cells which the second messenger c AMP stimulates
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http://highered.mcgraw- hill.com/sites/0072507470/student_view0/chapter17/anim ation__second_messenger__camp.html http://highered.mcgraw- hill.com/sites/0072507470/student_view0/chapter17/anim ation__second_messenger__camp.html
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First and second messengers and amplification ► http://bcs.whfreeman.com/thelifewire/conte nt/chp15/15020.html http://bcs.whfreeman.com/thelifewire/conte nt/chp15/15020.html http://bcs.whfreeman.com/thelifewire/conte nt/chp15/15020.html ► http://www.sinauer.com/cooper/4e/animati ons1503.html http://www.sinauer.com/cooper/4e/animati ons1503.html http://www.sinauer.com/cooper/4e/animati ons1503.html
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make a table to show the names of the hormones secreted by the adrenal glands, the cells which secrete them and their effects
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Aims of today’s lesson – preparing for next promonitor test on Monday 30 th November ► check exam answer on nerves ► try question on control of blood glucose ► review glucose control + diabetes ► review homeostasis + temperature control + heart rate control ► remember extra Biology on Fri 2-3 this week
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Introducing the control of blood glucose Introducing the control of blood glucose Homeostasis – maintaining the internal environment stable within certain limits by negative feedback Negative feedback - a change produces a response which eliminates the change; this needs a receptor which detects a stimulus, an effector which responds and communication between them e.g. nerves or hormones Diabetes – homeostasis is not working for blood glucose concentration
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Symptoms of high blood sugar / diabetes ► glucose in urine plus urine plus
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The islets of Langerhans in the pancreas
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The pancreas – an exocrine and endocrine gland
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Independent work for today and Monday ► answer questions 1 – 6 and complete diagram about control of glucose in plasma ► read the article on control of blood glucose by insulin and glucagon by Thursday 5 th Nov ► for at least 2 frequently asked questions from the diabetes task, research the answers and prepare 2 or 3 power point slides on each; ► send your slides to me and be prepared to share your work with the class on Tuesday 10 th November ► answer SAQ 5 (check answers in electronic version on book on MOODLE) + exam question – bring complete to lesson on Tuesday 10 th November
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Aims of today’s lesson ► check answers to questions 1 – 6 and answer question 7 ► check SAQ 5 in lesson – hand in exam question for marking ► listen to some student presentations about diabetes to check your understanding ► explain how insulin secretion is controlled
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Set up a microscope and find:- ► cells of the Islets of Langerhans in the pancreas ► diabetes rap ► http://www.youtube.com/watch?v=DJdIyBIuTGM http://www.youtube.com/watch?v=DJdIyBIuTGM
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The control of blood glucose and diabetes An example of homeostasis and negative feedback
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a) islets of Langerhans b) protein / polypeptide c) glucagon; insulin d) actual size = 41 000um / 30 000 = 1.4um e) fall detected by a and b cells; secretion of insulin decreases; secretion of glucagon increases; hormone in blood to receptor; on liver cell; glycogen glucose; fats respired; gluconeogenesis; glucose into blood f) more rapid response; shorter duration response; less chance of immune response; killing animals is a sensitive ethical issue; insulin from animals is not identical in amino acid sequence to human insulin; cheaper and easier to produce large amounts; less chance of disease
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Aims of today’s lesson ► To understand independent work on sense organs and neurones (nerve cells) to be completed by lesson on Monday 16 th November ► progress reviews ► check exam question answers – individually and with whole class ► describe and evaluate the treatment of type 1 and type 2 diabetes now and in the future e.g. inject insulin, use stem cells, control diet ► listen to some student presentations about diabetes to check your understanding
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Can you answer these questions about the heart? You must hand in your answer at the end of the lesson ► what is meant by the word ‘myogenic’ 1 ► describe how the SAN, AVN and Purkyne fibres work together during a heart beat 4 ► your heart beat rate can be increased during exercise so that muscle cells receive extra oxygen and glucose from blood and extra carbon dioxide is carried away; explain how this happens (include a diagram if this helps) 10 ► http://www.nhlbi.nih.gov/health/dci/Diseases/hhw/hhw_electrical.html http://www.nhlbi.nih.gov/health/dci/Diseases/hhw/hhw_electrical.html
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ECGs – normal or abnormal?
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