Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download File - Groby Bio Page
Document related concepts
Transcript
Communication and Homeostasis The Pancreas Learning Objective Know about the Pancreas Success Criteria Describe the histology of the pancreas Outline its role as an endocrine and exocrine gland Explain how blood glucose is regulated Starter Write down as much as you know about the pancreas in a mindmap PANCREAS AND ASSOCIATED ORGANS The Pancreas Has both endocrine and exocrine functions Exocrine (duct) Most cells make and release digestive enzymes Cells are found in small groups surrounding tubules into which they secrete the enzymes Tubules join to make the pancreatic duct Exocrine Enzymes in pancreatic fluid – Amylase: A carbohydrase – Trypsinogen: An inactive protease – Lipase Contains sodium hydrogencarbonate (an alkaline) Neutralises digestive system (having just left the stomach) Endocrine Islets of Langerhans contain two different type of cells that secrete hormones These are well supplied with blood capillaries so hormones can be secreted into blood THE ALPHA AND BETA CELLS IN ISLET OF LANGERHANS Islet of Langerhans Islet of Langerhans Alpha (α) cells Make and secrete the hormone GLUCAGON Target cells: hepatocytes (liver cells) Glucagon causes blood glucose levels to rise Glycogen to glucose (glycogenolysis) Amino acids and fats to glucose (gluconeogenesis) Beta (β) cells Make and secrete the hormone INSULIN Target cell: hepatocytes, muscle, brain Insulin causes blood glucose levels to go down Insulin binds activating adenyl cyclase, making cAMP Glucose converted to glycogen (glycogenesis) Pancreas June 11 Pancreas June 11 Insert Pancreas June 11 Markscheme Pancreas June 11 Markscheme Task: WITHOUT USING NOTES Make a flow diagram to show what happens in the pancreas when: – Rise in blood glucose concentration – Fall in blood glucose concentration Can use feedback loop OR help cards Controlling Blood Glucose Concentration RISE FALL FALL Normal Concentration RISE Detected by β cells in the islets of Langerhans RISE FALL FALL Normal Concentration RISE Detected by β cells in the islets of Langerhans β cells secrete insulin into the blood RISE FALL FALL Normal Concentration RISE Detected by β cells in the islets of Langerhans β cells secrete insulin into the blood Insulin detected by receptors RISE FALL Cells remove glucose from blood FALL Normal Concentration RISE Detected by β cells in the islets of Langerhans β cells secrete insulin into the blood Insulin detected by receptors RISE FALL Detected by α cells in the islets of Langerhans Cells remove glucose from blood FALL Normal Concentration RISE Detected by β cells in the islets of Langerhans β cells secrete insulin into the blood Insulin detected by receptors RISE FALL Detected by α cells in the islets of Langerhans Cells remove glucose from blood FALL Normal Concentration α cells secrete glucagon into the blood RISE Detected by β cells in the islets of Langerhans β cells secrete insulin into the blood Insulin detected by receptors RISE FALL Detected by α cells in the islets of Langerhans Cells remove glucose from blood FALL Normal Concentration α cells secrete glucagon into the blood Glucagon detected by receptors RISE Detected by β cells in the islets of Langerhans β cells secrete insulin into the blood Insulin detected by receptors RISE FALL Detected by α cells in the islets of Langerhans Cells remove glucose from blood FALL Normal Concentration α cells secrete glucagon into the blood Glucagon detected by receptors RISE Cells release glucose into blood PLENARY Blood Glucose Jan 12 [6] Blood Glucose Jan 12 Markscheme
