1. Endocrine System

2. Crash Course Review of Endocrine System http://www.youtube.com/watch?v=WVrlHH1 4q3o http://www.youtube.com/watch?v=WVrlHH1 4q3o This video clip will help you review some of the info that you just took notes on in your groups. Keep your notes out and add to them with any additional new information from the video.

3. Types of Signaling Endocrine – Hormones travel through the blood stream throughout the entire body – Act on a variety of tissues Paracrine – Target cells are near the secreting cells – Neurons, clotting factors Autocrine – Secreted molecules act on the secreting cell itself – T cell activation Immune response Pheromones – Molecules are secreted into the external environment – Marking territory, attracting mates, etc.

4. Hormone Responses Hormones can cause different responses on different tissues – determined by types of receptors on target tissue and signal transduction pathways – Ex. Epinephrine Different responses in different target tissues

6. Types of Hormones Peptide (Water Soluble) – Can’t cross membrane – Released by exocytosis – Bind to cell-surface signal receptors – Can cause a cytoplasmic response and alter gene transcription inside cell – http://highered.mcgraw- hill.com/olcweb/cgi/pluginpop.cgi?it=swf::535::535::/sites/dl/free/007243 7316/120109/bio48.swf::Action%20of%20Epinephrine%20on%20a%20Liv er%20Cell http://highered.mcgraw- hill.com/olcweb/cgi/pluginpop.cgi?it=swf::535::535::/sites/dl/free/007243 7316/120109/bio48.swf::Action%20of%20Epinephrine%20on%20a%20Liv er%20Cell Steroid Hormones (lipid soluble) – water insoluble – Travel in blood via transport proteins – Can easily diffuse across cell membranes – Bind to intracellular signal receptors and cause changes in gene transcription – http://highered.mcgraw- hill.com/olcweb/cgi/pluginpop.cgi?it=swf::535::535::/sites/dl/free/007243 7316/120109/bio47.swf::Mechanism%20of%20Thyroxine%20Action http://highered.mcgraw- hill.com/olcweb/cgi/pluginpop.cgi?it=swf::535::535::/sites/dl/free/007243 7316/120109/bio47.swf::Mechanism%20of%20Thyroxine%20Action

8. Steroid or Peptide Hormone?

10. Negative Feedback Maintains homeostasis Feedback loop initiated by a stimulus Response reduces the initial stimulus

12. Negative Feedback in Menstrual Cycle

13. Menstrual and Ovarian Cycles Feedback between Glands Low estrogen and progesterone cause the hypothalamus to increase GnRH High GnRH causes the pituitary to release FSH and LH FSH causes follicle to develop in ovary FSH and LH cause follicle to release estrogen

14. Continued… Estrogen increases the thickness of uterine lining Major increase in LH causes ovulation Ruptured follicle (corpus luteum) releases estrogen and progesterone Progesterone thickens and maintains uterine lining Increase of estrogen and progesterone slow release of GnRH ( decrease FSH and LH)

15. Continued… No Fertilization: Fertilization: Corpus luteum disappears and progesterone and estrogen decrease. Uterine lining sheds Embryo implants in uterus and forms a placenta. Placenta releases HCG which causes corpus luteum to continue to release progesterone and estrogen (which will maintain the uterine lining) until the placenta begins to make it’s own estrogen and progesterone.

16. Male Hormones GnRH from the hypothalamus stimulates the pituitary to release FSH and LH. Testosterone causes testes to produce sperm FSH stimulates cells in the testes to nourish sperm LH stimulates the testes to release testosterone.