1. Hormones & The Endocrine Glands
10.1 & 10.2

2. Image from: http://leavingbio

3. Hormones
chemicals produced by cells in one part of the body that regulate processes in another part of the body
endocrine glands secrete hormones directly into the blood (exocrine glands into ducts)

4. Endocrine vs. Nervous
both systems integrate and control organs and tissues
nervous system helps body to adjust quickly to changes
endocrine system maintains control over longer periods of time

5. Types of hormones
protein hormones are amino acid chains and are water-soluble; diffuse well through blood and fluids
steroid hormones are derived from cholesterol and are soluble in blood when combined with hydrophilic carrier proteins

6. Water-Soluble Hormones
(Image from:

7. Animation…
Narrated animation of water-soluble (protein) hormones. Specific example of using cAMP to activate proteins in the target cell:

8. Fat-Soluble Hormones
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9. Animation… Narrated animation of steroid hormone action:

10. Image from: http://bio1152. nicerweb. com/Locked/media/ch45/endocrine

11. Image from: http://www.mayoclinic.com/health/medical/IM00643

12. Hypothalamus part of the nervous system
produces neurohormones which diffuse into the blood and travel to the pituitary gland

13. Pituitary Gland “master gland”
secretes hormones that control other endocrine glands
under the nervous control of the hypothalamus

14. Pituitary Gland
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15. Anterior Pituitary
neurohormones from the hypothalamus stimulate or inhibit release of hormones
produces, stores & releases:
prolactin (PSH)
growth hormone
tropic hormones (TSH, ACTH, FSH, LH)
melanocyte-stimulating hormone MSH

16. “Intermediate Lobe” not very developed in humans
releases endorphins, “natural painkillers”
endorphins function in the nervous system in pathways that control pain)

17. Posterior Pituitary
stores and releases hormones produced by the hypothalamus:
anti-diuretic hormone (ADH)
oxytocin
ADH reabsorption of water in distal convoluted tubule
Inhibited by alcohol & caffeine
Oxytocin: childbirth, milk release

18. Image from: http://www. thyroiduk. org

19. Thyroid Glands stimulated by TSH secrete thyroxin (T4)
in target cell, T4 is converted to T3, triiodothyronine, which enters nucleus and combines with receptors
affects growth, development, metabolism, etc.

20. Thyroid Glands
also has specialized cells that secrete calcitonin (protein hormone)
lowers Ca2+ levels in blood by stimulating deposition in bones, and reducing Ca2+ uptake by kidneys

21. Negative Feedback hypothalamus release TRH
TRH causes the anterior pituitary to release TSH
TSH causes the thyroid to release T4
T4 inhibits secretion of TSH by the anterior pituitary

22. Image from: http://www.mayoclinic.com/health/medical/IM03488

23. Parathyroid Glands produce parathyroid hormone (PTH)
when Ca2+ levels are too low, PTH is released:
stimulates bones to release Ca2+
stimulates kidneys to activate vitamin D, which acts on cells in intestines to increase Ca2+ absorption

24. Image from: http://www. nichd. nih

25. Adrenal Glands adrenal medulla secretes epinephrine & norepinephrine
“fight or flight” situations
adrenal cortex secretes hormones such as aldosterone (osmoregulation), cortisol (blood glucose regulation)

26. Image from: http://healinghaven. typepad

27. Pineal Gland
regulates biological rhythms due to secretion of melatonin
light (detected by the eye) inhibits melatonin secretion