Study guide…

1. Study guide… • Compare and contrast exocrine and endocrine glands. • Name the major glands and their functions in the endocrine system. • What is diabetes (Type 1 and 2) and how might you prevent Type 2? • How does the endocrine system maintain homeostasis? • Choose one endocrine disorder to write about…

2. Endocrine system

3. Exocrine vs. endocrine glands • Exocrine glands secrete their products into ducts that carry these products to other organs or outside the body • Endocrine glands secrete their products directly into the bloodstream

4. What are hormones? • Hormones are chemical signals that promote communication between cells, body parts and even individuals • Hormones: • Prostaglandins • Pheromones • Peptide hormones • Steroid hormones

5. Major glands of the endocrine system • Hypothalamus • Pineal gland • Posterior pituitary gland • Anterior pituitary gland • Thyroid gland • Parathyroid glands • Thymus gland • Adrenal glands-medulla & cortex • Pancreas • Ovaries • Testes

6. 1. Hypothalamus • Regulates internal environment through the autonomic nervous system • Helps control body temperature • Helps control water balance • Controls secretions of other endocrine glands

7. 2. Pineal gland • Located in the brain • Secretes ___________

8. 3. Posterior pituitary gland • Stores antidiuretic hormone (ADH) and oxytocin that are produced by the hypothalamus • ADH • Oxytocin • (What effect could this hormone have on men?)

9. 4. Anterior pituitary gland Hormones produced by the anterior pituitary: • Thyroid-stimulating hormone (TSH) • Adrenocorticotropic hormone (ACTH) • Gonadotropic hormones (FSH, LH) • Melanocyte-stimulating hormone (MSH) • Growth hormone (GH) • Prolactin (PRL)-production of _______

10. What happens when the body produces too much or too little GH? • Pituitary dwarfism – too little GH is produced during childhood that results in small stature • Gigantism – too much GH is produced during childhood • Acromegaly – overproduction of GH as an adult

11. What happens when GH is produced in high amounts during adulthood?

12. 5. Thyroid gland • A large gland located below the larynx • Iodine is needed in the diet to allow the thyroid gland to produce its hormones • It produces: • Thyroxine (TH) • Calcitonin

13. Thyroid abnormalities • Simple goiter – thyroid enlarges due to lack of iodine in the diet • Hypothyroidism – low blood levels of thyroid hormones • Congenital hypothyroidism • Myxedema • Hyperthyroidism – excess thyroid hormones in the blood • Exophthalmic goiter • Thyroid tumor

14. Thyroid abnormalities

15. 6. Parathyroid glands • Small glands embedded in the surface of the thyroid gland • Produces parathyroid hormone (PTH)

16. Too much calcium? • Thyroid secretes calcitonin • Not enough calcium? • Parathyroid secretes PTH

17. 7. Thymus gland • Lies beneath the sternum • This gland is largest and most active during childhood • Secretes hormones called thymosins-which lymphocytes mature here after leaving the bone marrow? ________

18. 8. Adrenal glands • Glands that sit on top of the kidneys • 2 parts of each gland • Adrenal medulla: controlled by the nervous system…Which division is responsible for fight-flight? ________________________ • Adrenal cortex: portions are controlled by ______________from the anterior pituitary

19. Adrenal medulla • Inner portion of the adrenal glands • Produces: hormones that allow a short-term response to stress (“fight or flight” response) • Epinephrine (adrenaline) • Norepinephrine

20. Adrenal cortex • Outer portion of the adrenal glands • Produces hormones that provide a long-term response to stress • 2 major types of hormones: • Mineralocorticoids • Glucocorticoids

21. Adrenal glands can malfunction • Addison’s disease – hyposecretion of glucocorticoids • Fatigue, muscle weakness, dizziness, weight loss, difficulty standing, nausea • Causes • TB (20%) • Auto-immune (80%)

22. Adrenal glands can malfunction • Cushing syndrome – hypersecretion of glucocorticoids

23. 9. Pancreas • Located below the stomach • Composed of 2 tissues: • Exocrine: produces and secretes digestive juices • Endocrine (islets of Langerhans): produces and secretes hormones • Insulin • Glucagon

24. Too much glucose? • Pancreas secretes insulin • Not enough glucose? • Pancreas secretes glucagon

25. Health focus: What is diabetes? • Inability to control blood glucose levels • 18 million people in the US have diabetes • General symptoms: • Frequent urination • Unusual hunger and/or thirst • Unexplained change in weight • Blurred vision • Sores that heal slowly or not at all • Excessive fatigue • Long-term effects are blindness, loss of limbs, nerve deterioration, kidney and cardiovascular disease

26. Diabetes: Understanding the 2 types • Type 1: • Usually early-onset • Autoimmune disorder • Pancreatic cells are attacked and cannot produce insulin • Need insulin injections • Type 2: • Usually adult-onset and most common type • Cells do not respond to insulin • Diet and exercise are important for controlling this and may even prevent

27. Sex hormones Ovaries Testes Produce androgens (e.g. testosterone) • Produce estrogen and progesterone

28. Hormones from other tissues • Erythropoietin: • secreted by the kidney to stimulate production of ________ • Leptin: produced by fat cells and acts on the hypothalamus to give a feeling of being full • Prostaglandins: • Some cause smooth muscle contraction • Aspirin and ibuprofen block the synthesis of these