1. Endocrine system (endo) within; as apposed to outside the body
(crine) – separate; separating from the secreting cell
Endocrine system

2. Two systems coordinate communication throughout the body: the endocrine system and the nervous system
The endocrine system secretes hormones that coordinate slower but longer-acting responses including reproduction, development, energy metabolism, growth, and behavior
The nervous system conveys high-speed electrical signals along specialized cells called

3. How insulin signals the body to lower blood Glucose
Steps of the endocrine system
How insulin signals the body to lower blood Glucose

4. Signal is given You eat a meal with carbohydrates… Yum!
Your body senses a rise in blood glucose (specifically in the pancreas)
Signals that stimulate other hormones include: high or low blood pressure, increase or decrease in body temperature, sensing danger, baby suckling, decreased oxygen to blood, etc.

5. Hormones released from an endocrine gland or cells
Insulin is released from the pancreas
Other hormones could be released from any of these endocrine cells

6. But wait… what are hormones
Insulin is a protein
… but others can be lipids or amines

7. Once released, Hormones travel through the blood
The insulin is sent off throughout the body… it is not directed to any specific tissue
All hormones travel through the blood unless they are a localized signal

8. How do certain hormones only target specific tissues
Insulin stimulates almost all cells in the body… but not all hormones do

9. Ex. Epinephrine (AKA fight or flight hormone)

10. The hormone causes a response in the cell
Insulin stimulates cells to take in glucose and to stop breaking down glycogen in the liver
Glycogen is just a big sugar storage molecule (mainly found in liver)
Signals from other hormones can cause an increase in a certain enzyme, stop transcription of some genes, constriction or dilation in muscle cells, etc.

11. How does the endocrine gland/cells know when to stop making the hormones?
Negative Feedback!!!

12. Negative Feedback Ex. Insulin and Glucagon
Insulin lowers blood glucose by slowing the breakdown of glycogen
Glucagon heightens blood glucose by increasing breakdown of glycogen

13. Insulin Beta cells of pancreas release insulin into the blood.
Fig
Insulin
Beta cells of
pancreas
release insulin
into the blood.
STIMULUS:
Blood glucose level
rises.
Figure Maintenance of glucose homeostasis by insulin and glucagon
Homeostasis:
Blood glucose level
(about 90 mg/100 mL)

14. Body cells take up more glucose. Insulin Beta cells of pancreas
Fig
Body cells
take up more
glucose.
Insulin
Beta cells of
pancreas
release insulin
into the blood.
Liver takes
up glucose
and stores it
as glycogen.
STIMULUS:
Blood glucose level
rises.
Blood glucose
level declines.
Figure Maintenance of glucose homeostasis by insulin and glucagon
Homeostasis:
Blood glucose level
(about 90 mg/100 mL)

15. Alpha cells of pancreas release glucagon.
Fig
Homeostasis:
Blood glucose level
(about 90 mg/100 mL)
STIMULUS:
Blood glucose level
falls.
Figure Maintenance of glucose homeostasis by insulin and glucagon
Alpha cells of pancreas
release glucagon.
Glucagon

16. Blood glucose level rises.
Fig
Homeostasis:
Blood glucose level
(about 90 mg/100 mL)
STIMULUS:
Blood glucose level
falls.
Blood glucose
level rises.
Alpha cells of pancreas
release glucagon.
Figure Maintenance of glucose homeostasis by insulin and glucagon
Liver breaks
down glycogen
and releases
glucose.
Glucagon

17. Fig
Body cells
take up more
glucose.
Insulin
Beta cells of
pancreas
release insulin
into the blood.
Liver takes
up glucose
and stores it
as glycogen.
STIMULUS:
Blood glucose level
rises.
Blood glucose
level declines.
Homeostasis:
Blood glucose level
(about 90 mg/100 mL)
Figure Maintenance of glucose homeostasis by insulin and glucagon
STIMULUS:
Blood glucose level
falls.
Blood glucose
level rises.
Alpha cells of pancreas
release glucagon.
Liver breaks
down glycogen
and releases
glucose.
Glucagon

18. Diabetes
Deficiency of insulin or decreased response to insulin, so blood glucose is high
Type I diabetes mellitus (insulin-dependent) is an autoimmune disorder in which the immune system destroys pancreatic beta cells (the ones that make insulin)
Type II diabetes mellitus (non-insulin-dependent) involves insulin deficiency or reduced response of target cells due to change in insulin receptors

19. Follow the path of 1 of these
ADH
Growth Hormone (GH)
Oxytocin
Triiodothyronine (T3) and thyroxine (T4)
Epinephrine

20. Use play dough to describe it to another group
Include
What is it stimulated by
Where is it released from
What type of hormone it is (chemical class)
What tissues it acts on
What it does in the cell or tissue
How is it regulated
Disorders for non-regulation