1. Bell Ringer: What region of the brain controls the Pituitary Gland? What is the “boss” of the Endocrine system? What is the function of the Pituitary Gland? What are the “broadcasters”? What do the “broadcasters”release into the bloodstream? Hypothalamus Pituitary Gland Regulates all other glands with hormones through the bloodstream Glands Hormones

2. Unit 10: Feedback Loops

3. Fight or Flight Response http://www.youtube.com/watch?v=4g25d7_Afmc 1.Increase in strength 2.No feelings of pain 3.Heightened senses 4.Sudden burst of energy 5.Increased breathing rate

4. Positive Feedback Loop An initial change causes a stimulus furthering the change in the same direction.

5. Positive Feedback Loop Example: – The hormone Oxytocin causes contractions in childbirth.

6. Positive Feedback Loop Example: – The hormone Oxytocin causes contractions in childbirth. – The contractions cause the release of more Oxytocin.

7. Positive Feedback Loop Example: – The hormone Oxytocin causes contractions in childbirth. – The contractions cause the release of more Oxytocin from Hypothalamus. – Continues until child is born.

8. Negative Feedback Loop The output shuts off the original stimulus or reduces its intensity.

9. Negative Feedback Loop Example: – Blood glucose rises after a meal

10. Negative Feedback Loop Example: – Blood glucose rises after a meal – Insulin is released into bloodstream from Pancreas http://www.mayoclinic.org/diseases- conditions/hypoglycemia/basics/causes/con- 20021103

11. Negative Feedback Loop Example: – Blood glucose rises after a meal – Insulin is released into bloodstream from Pancreas – Glucose becomes absorbed into cells/tissues which then lowers blood glucose

12. Correct Order: 1.Thyroxine levels drop in the body which lowers Metabolism. Loop Starts…… 2. Body sends a “low Thyroxine” signal to the Hypothalamus 3. Hypothalamus secretes (TRH) Thyrotropin Releasing Hormone 4. TRH is sent to the Pituitary Gland 5. Pituitary Gland secretes (TSH) Thyroxine Secreting Hormone 6. TSH is sent to Thyroid 7. Thyroid secretes Thyroxine into blood which then spreads through body 8. Thyroxine levels increase in the body and Metabolism increases. Body sends a “ok” signal to the Hypothalamus. 9. Homeostasis in Body again …………Thyroxine Loop stops Unit 10: Feedback Loop Homework/Notes In the box to the right, Create a Concept Map based on the information above. Circle around the Glands Highlight the Hormones Use solid lines with arrows to show movement and direction of Hormones Use a dashed line to show input signals from the body If you can’t figure this out, you must come see me during Intervention prior to class. BODY Normal Levels of Thyroxine (Homeostasis) Print this page Name:_____________________________ Per:_____ Low Thyroxine in Body – Homework (Negative Feedback Loop Example) Unit 10: Feedback Loops Positive Feedback Loop:Negative Feedback Loop: Blood