1 / 29

Ch. 32 Warm-Up

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.

toniaj
Télécharger la présentation

Ch. 32 Warm-Up

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  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. Chapter 32 – Part II Endocrine System

  3. 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.

  4. Types of Intercellular Signaling

  5. 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

  6. Discovery Video: Endocrine System

  7. Simple Endocrine Pathway

  8. Simple Neuroendocrine Pathway

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

  10. Types of Hormones Peptide Steroid 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 • 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

  11. Peptide vs. Steroid Hormones

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

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

  14. Master Glands Hypothalamus Pituitary Gland

  15. Master Glands • 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

  16. Hypothalamusregulation ofPosterior Pituitarygland

  17. Hypothalamusregulation ofAnterior Pituitarygland

  18. BIOFLIX: HOMEOSTASIS – BLOOD SUGAR

  19. Insulin & Glucagon: Control blood glucose levels

  20. High blood glucose Control of Blood Glucose Body cells take up glucose Liver stores glucose as glycogen Insulinreleased from pancreas Liver breaks down glycogen and releases glucose into blood Blood glucose drops Glucagonreleased from pancreas

  21. 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

  22. THYROID GLAND: REGULATION OF METABOLISM

  23. 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

  24. 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

  25. Stress and the Adrenal Gland

More Related