1. Ch. 32 Warm-Up
What type of behavior in animals might be triggered by cold temperatures?
What type of behaviors might be triggered in hot temperatures?
List 2 examples of negative feedback. List 2 examples of positive feedback.
What is the main type of chemical messenger in the endocrine system? The nervous system?

2. Ch. 32 Warm-Up Compare peptide hormones to steroids.
Explain how insulin and glucagon work to regulate blood sugar levels.
Which glands and hormones respond when your body is under stress?

3. Chapter 32 – Part II
Endocrine System

4. What you must know:
The endocrine system is one of two body systems for communication and regulation.
How hormones are transported, bind to specific target cells, and trigger cellular responses.
The secretion, target, action, and regulation of at least two hormones.
An illustration of both positive and negative feedback in the regulation of homeostasis by hormones.

5. Types of Intercellular Signaling

6. Endocrine System = Hormone-secreting cells and Tissues
Endocrine Glands: ductless; secrete hormones directly into body fluids
Hormones: chemical signals that cause a response in target cells (receptor proteins for specific hormones)
Affects 1 tissue, a few, or most tissues in body
OR affect other endocrine glands
Regulation by Positive & Negative Feedback

7. Pheromones Hormones Local Regulators
Chemical signal from 1 individual to another individual
Chemical signal from endocrine gland through blood to target cell
Chemical signal from one cell to an adjacent cell
Eg. ant trail; sex phermones
Eg. peptide, steroid hormones
Eg. cytokines, growth factors, nitric oxide (NO)

9. Discovery Video: Endocrine System

10. Simple Endocrine Pathway

11. Simple Neuroendocrine Pathway

14. Negative feedback systems:
Thyroid hormones
Blood Ca2+ levels
Blood glucose levels
Positive feedback system:
Oxytocin (birthing process; release of milk/suckling)

15. Types of Hormones Peptide Steroid Water-soluble
Bind to receptors on plasma membrane & triggers signal transduction pathway
Affects protein activity already present in cell
Rapid response
Short-lived
Eg. oxytocin, insulin, epinephrine
Lipid-soluble
Enters cell & binds to intracellular receptors
Causes change in gene expression (protein synthesis)
Slower response
Longer life
Eg. androgens (testosterone), estrogen, progesterone, cortisol, thyroid hormone

16. Peptide vs. Steroid Hormones

17. Fight or Flight Response
Learn Genetics Video Clip (4:29 min)
Fight or Flight Response

18. Epinephrine: One hormone  Many effects!
Liver cells break down glycogen and release glucose
Blood vessels to skeletal muscles dilate
Blood vessels to intestines constrict

19. Master Glands
Hypothalamus
Pituitary Gland

20. Master Glands Hypothalamus Pituitary Gland
Receives info from nerves and brain
Initiates endocrine signals
Hypothalamus
Posterior pituitary gland:
Oxytocin: contract uterine muscles, eject milk in nursing
Antidiuretic hormone (ADH): promote H2O retention by kidneys
Pituitary Gland
Anterior pituitary gland:
Follicle-stimulating hormone (FSH): development of ovarian follicles (eggs); promote sperm production
Luteinizing hormone (LH): trigger ovulation; stimulate testosterone production in testes

21. Hypothalamus regulation of Posterior Pituitary gland

22. Hypothalamus regulation of Anterior Pituitary gland

23. BIOFLIX: HOMEOSTASIS – BLOOD SUGAR

24. Insulin & Glucagon: Control blood glucose levels

25. Control of Blood Glucose
High blood glucose
Liver breaks down glycogen and releases glucose into blood
Insulin released from pancreas
Body cells take up glucose
Liver stores glucose as glycogen
Glucagon released from pancreas
Blood glucose drops

26. Diabetes Mellitus Type I diabetes (10%):deficiency of insulin
Insulin-dependent
Autoimmune disorder  beta cells of pancreas destroyed
Type II diabetes (90%): failure of target cells to respond to insulin
Non-insulin dependent
Insulin produced  cells don’t respond (defect in insulin receptor or response pathway)
Risk factors: obesity, lack of exercise

27. REGULATION OF METABOLISM
THYROID GLAND:
REGULATION OF METABOLISM

28. Homeostatic Imbalance: Graves Disease
Autoimmune disorder
Antibodies bind to TSH receptor
Hyperthyroidism (overproduce T3 and T4 hormones)
Bypass TSH negative feedback loop
High temp, sweating, weight loss, high BP

29. Homeostatic Imbalance: Hashimoto’s Thyroiditis
Autoimmune disorder
Antibodies destroy thyroid gland
Low levels of thyroid hormone
TSH levels rise
Hypothyroidism
Low temp, gain weight, sluggish, low heart rate

30. Stress and the Adrenal Gland