1. Communication and Homeostasis
The Pancreas

2. Spec
(c) (i) the histology of the pancreas (ii) the examination and drawing of stained sections of the pancreas to show the histology of the endocrine tissues
To include the endocrine tissues. PAG1 HSW4

3. Mark PPQ from last lesson
FLIP Learning
See Hormones 1 ppt

6. Learning Objective Success Criteria
Know about the Pancreas
Describe the histology of the pancreas
Explain how blood glucose concentration is regulated by negative feedback

7. Starter
Write down as much as you know about the pancreas in a mindmap

8. PANCREAS AND ASSOCIATED ORGANS

9. Has both endocrine and exocrine functions
The Pancreas
Has both endocrine and exocrine functions

10. 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

11. 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)

12. 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

13. THE ALPHA AND BETA CELLS IN ISLET OF LANGERHANS
Acinus of exocrine tissue

14. Pancreas Histology
Micrographs and diagrams on p68-69

15. Pancreas Histology

16. Drawing Microscope Slides
Annotations
Whilst a label might be the name of a tissue, an annotation adds a descriptive quality such as shape, size or colour.
Drawings from a microscope
Single, clear lines drawn with a sharp pencil.
No shading or colour on the diagram.
Informative title to be included.
Scale included (e.g. high power, low power, x80, x10) to show approximate magnification.
High power diagrams show a few adjacent cells only; adjacent cells must have complete lines.
Cells or tissues should be in correct proportions.
Label lines drawn in pencil using a ruler.

17. Task
Task: Draw a high power drawing of the pancreas

18. Alpha (α) cells Make and secrete the hormone GLUCAGON
Target cells: hepatocytes
Glucagon causes blood glucose levels to rise
Glycogen to glucose (glycogenolysis)
Amino acids and fats to glucose (gluconeogenesis)

19. Beta (β) cells Make and secrete the hormone INSULIN
Target cell: hepatocytes, muscle
Insulin causes blood glucose levels to go down
Insulin binds activating adenyl cyclase, making cAMP
Glucose converted to glycogen (glycogenesis)

20. Plenary 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
Negative Feedback: Control of blood glucose concentration
Can use feedback loop as a writing frame

21. Controlling Blood Glucose Concentration

22. RISE
FALL
Normal Concentration
FALL
RISE

23. Detected by β cells in the islets of Langerhans
RISE
FALL
Normal Concentration
FALL
RISE

24. Detected by β cells in the islets of Langerhans
β cells secrete insulin into the blood
RISE
FALL
Normal Concentration
FALL
RISE

25. Detected by β cells in the islets of Langerhans
β cells secrete insulin into the blood
Insulin detected by receptors
Cells remove glucose from blood
RISE
FALL
Normal Concentration
FALL
RISE

26. Detected by β cells in the islets of Langerhans
β cells secrete insulin into the blood
Insulin detected by receptors
Cells remove glucose from blood
RISE
FALL
Normal Concentration
FALL
RISE
Detected by α cells in the islets of Langerhans

27. Detected by β cells in the islets of Langerhans
β cells secrete insulin into the blood
Insulin detected by receptors
Cells remove glucose from blood
RISE
FALL
Normal Concentration
FALL
RISE
α cells secrete glucagon into the blood
Detected by α cells in the islets of Langerhans

28. Detected by β cells in the islets of Langerhans
β cells secrete insulin into the blood
Insulin detected by receptors
Cells remove glucose from blood
RISE
FALL
Normal Concentration
FALL
RISE
α cells secrete glucagon into the blood
Detected by α cells in the islets of Langerhans
Glucagon detected by receptors

29. Detected by β cells in the islets of Langerhans
β cells secrete insulin into the blood
Insulin detected by receptors
Cells remove glucose from blood
RISE
FALL
Normal Concentration
FALL
RISE
α cells secrete glucagon into the blood
Detected by α cells in the islets of Langerhans
Cells release glucose into blood
Glucagon detected by receptors

30. Set Standard Homework