Presentation on theme: "Ch. 40 Warm-Up 1.What type of behavior in animals might be triggered by cold temperatures? 2.What type of behaviors might be triggered in hot temperatures?"— Presentation transcript:
Ch. 40 Warm-Up 1.What type of behavior in animals might be triggered by cold temperatures? 2.What type of behaviors might be triggered in hot temperatures? 3.List 2 examples of negative feedback. List 2 examples of positive feedback. 4.What is the main type of chemical messenger in the endocrine system? The nervous system?
Warm-Up 1.Compare and contrast the nervous system with the endocrine system. (Focus on the effects on the body) 2.Define neurosecretory cell. What is its function? 3.Give an example of positive and negative feedback in the endocrine system. How do they function?
Ch. 45 Warm-Up 1.Compare peptide hormones to steroids. 2.Explain how insulin and glucagon work to regulate blood sugar levels. 3.Which glands and hormones respond when your body is under stress?
Chapter 45 Hormones and the Endocrine System A hormone called ecdysteroid regulates the timing of metamorphosis in this anise swallowtail butterfly.
You must know: Two ways hormones affect target organs. The secretion, target, action, and regulation of at least 3 hormones. An illustration of both positive and negative feedback in the regulation of homeostasis by hormones.
Types of Intercellular Signaling
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
PheromonesHormones 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)
Types of Hormones Peptide Water-soluble plasma membrane Bind to receptors on plasma membrane & triggers signal transduction pathway already present Affects protein activity already present in cell Rapid response Short-lived Eg. oxytocin, insulin, epinephrine Steroid Lipid-soluble intracellular Enters cell & binds to intracellular receptors gene expression Causes change in gene expression (protein synthesis) Slower response Longer life Eg. androgens (testosterone), estrogen, progesterone, cortisol
Epinephrine Epinephrine: one hormone many effects 1.Liver cells break down glycogen and release glucose 2.Blood vessels to skeletal muscles dilate 3.Blood vessels to intestines constrict
Hypothalamus Pituitary Gland Master Glands
Hypothalamus Pituitary Gland Receives info from nerves and brain Initiates endocrine signals Posterior pituitary gland: Oxytocin: contract uterine muscles, eject milk in nursing Antidiuretic Hormone (ADH): promote H 2 O retention by kidneys 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 Master Glands
Hypothalamus regulation of Posterior Pituitary gland
Hypothalamus regulation of Anterior Pituitary gland
Insulin & Glucagon: Control blood glucose levels
Control of Blood Glucose High blood glucose Insulin Insulin released from pancreas Body cells take up glucose glycogen Liver stores glucose as glycogen Blood glucose drops Glucagon Glucagon released from pancreas glucose Liver breaks down glycogen and releases glucose into blood
Diabetes Mellitus Type I diabetes Type I diabetes (10%):deficiency of insulin – Insulin-dependent – Autoimmune disorder beta cells of pancreas destroyed Type II diabetes 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
Thyroid Gland Hypothalamus TRH Anterior pituitary TSH Thyroid T3T3 T4T4 Graves’ Disease: Autoimmune disorder Antibodies bind to TSH receptor Hyperthyroidism High temp, sweating, weight loss, high BP
Stress and the Adrenal Gland
Anabolic-Androgenic Steroid (AAS) Use Legally prescribed to treat hormone deficiency, loss of muscle mass (cancer, AIDS) Used to enhance performance and improve physical appearance
Effects of AAS Abuse Source: aggression extreme mood swings liver damage jaundice fluid retention high blood pressure increases in LDL (“bad” cholesterol) decreases in HDL (“good” cholesterol) renal failure severe acne For men—shrinking of the testicles, reduced sperm count, infertility, baldness, development of breasts, increased risk for prostate cancer For women—growth of facial hair, male- pattern baldness, changes in or cessation of the menstrual cycle, enlargement of the clitoris, deepened voice For adolescents—stunted growth due to premature skeletal maturation and accelerated puberty changes; risk of not reaching expected height if AAS is taken before the typical adolescent growth spurt In addition, people who inject AAS run the added risk of contracting or transmitting HIV/AIDS or hepatitis.