1. Ch. 40 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. 45 Warm-Up Compare peptide hormones to steroids.
Explain how insulin and glucagon work to regulate blood sugar levels.

3. Chapter 45 Hormones and the Endocrine System
A hormone called ecdysteroid regulates the timing of metamorphosis in this anise swallowtail butterfly.

4. Types of Intercellular Signaling

5. Endocrine System = Hormone-secreting cells + 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 (tropic hormones)
Regulation by Positive & Negative Feedback

6. 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)

8. Discovery Video: Endocrine System

9. 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

11. Epinephrine: one hormone  many effects
Liver cells break down glycogen and release glucose
Blood vessels to skeletal muscles dilate
Blood vessels to intestines constrict

12. Master Glands
Hypothalamus
Pituitary Gland

13. 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

14. Hypothalamus regulation of Posterior Pituitary gland

15. Hypothalamus regulation of Anterior Pituitary gland

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

19. BIOFLIX: HOMEOSTASIS – BLOOD SUGAR

20. Insulin & Glucagon: Control blood glucose levels

21. 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

22. 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

23. Thyroid Gland Graves’ Disease: Autoimmune disorder
Hypothalamus
TRH
Anterior
pituitary
TSH
Thyroid T3 T4
Graves’ Disease:
Autoimmune disorder
Antibodies bind to TSH receptor
Hyperthyroidism
High temp, sweating, weight loss, high BP

24. Stress and the Adrenal Gland