1. Endocrine system

2. Endocrine system 3 types of regulatory molecules:
1) Hormones: regulatory chemicals secreted into blood by endocrine gland
Work only on ____________ cells (those that can be influenced by its “message”)

3. Endocrine system 3 types of regulatory molecules:
2) Neurohormones: hormones released into blood by some neurons

4. Endocrine system 3 types of regulatory molecules:
3) Paracrine hormones: chemicals secreted by cells of organ that influence others in organ (not transported by blood)

5. Endocrine system
3) Paracrine hormones. Example: prostaglandins. Derived from cholesterol
Many functions: one is to promote inflammation (pain, fever)
Aspirin, ibuprofen, celebrex: inhibit prostaglandin production but vary in side effects (some can cause _____________ in small intestine, etc)

6. Endocrine system Hormone chemistry:
1) polypeptides: chains of amino acids (<100 aa’s long). Ex, insulin, ADH (antidiuretic hormone)
Structure of insulin

7. Endocrine system Hormone chemistry:
2) glycoproteins: long polypeptide (>100 aa’s long) with carbohydrate attached. Ex, FSH (follicle stimulating hormone) and luteinizing hormone (LH)

8. Endocrine system Hormone chemistry:
3) amines: variations of the amino acids tyrosine and tryptophan. Ex, adrenalin, thyroxine.
tyrosine
tyramine
adrenaline
tryptophan

9. Endocrine system Hormone chemistry:
4) steroids: lipids derived from cholesterol. Ex, testosterone, estradiol, progesterone
cholesterol

10. Endocrine system Most hormones are hydrophilic (water soluble)
Recall from BIOL 1020 that cell membranes are hydrophobic
This means that water-soluble molecules can’t cross them.
How signal transmitted into cells? By __________ protein in membrane

11. Endocrine system Hydrophilic hormone example
Hormone binding temporary, detaches and can travel to another cell and bind again (and again)
1 hormone molecule can signal many ________!

12. Endocrine system Hydrophobic hormones are steroids and thyroxine
They penetrate membranes and bind to receptors inside cell

13. Endocrine system
Example hydrophobic hormones are steroids (testosterone, estradiol) and thyroxine

14. Endocrine glands Pituitary gland: located under brain
Has two portions: anterior (in front) and posterior (in rear). Each portion with different embryonic origin and very different functions

15. Endocrine glands Posterior pituitary gland hormones
Antidiuretic hormone (ADH): influences water reabsorption in kidneys.
Note: alcohol consumption inhibits ADH secretion (so frequent need to _______________).

16. Endocrine glands Posterior pituitary gland hormones
Oxytocin: stimulates milk “let-down” in nursing mothers (milk secreted into ducts in breast). Also stimulates uterine contractions during childbirth.

17. Endocrine glands Anterior pituitary gland hormones
growth hormone (GH): stimulates growth of bone and muscle
Too much: gigantism
8 feet 11 inches, 485 pounds.
Lived 22 years, never
stopped growing!

18. Endocrine glands Anterior pituitary gland hormones
growth hormone (GH): stimulates growth of bone and muscle
Too little: pituitary dwarfism

19. Endocrine glands Anterior pituitary gland hormones
follicle stimulating hormone (FSH) and luteinizing hormone (LH): involved in menstrual cycle in females and sperm production in males

20. Endocrine glands Anterior pituitary gland hormones
follicle stimulating hormone (FSH) and luteinizing hormone (LH): involved in menstrual cycle in females and sperm production in males
prolactin (PRL): stimulates milk production in mammals

21. Endocrine glands
Thyroid gland: in throat just under larynx

22. Endocrine glands Thyroid gland hormone (main):
Thyroxine: helps set body’s metabolic rate
Too little: ______________. Often severe retardation.

23. Endocrine glands Parathyroid glands: On thyroid
Make parathyroid hormone (PTH): vital to maintain Ca+2 level in body
Can influence Ca+2 reabsorption in kidney, Ca+2 release from bone, and absorption of Ca+2 in small intestine.

24. Endocrine glands
Adrenal glands: Located on kidneys

25. Endocrine glands Adrenal glands Located on kidneys
Have cortex (outer) and medulla (inner) portions

26. Endocrine glands Adrenal glands
Medulla: secretes ______________ when stimulated by nerve system. Part of “fight or flight” response. Increase heart rate, blood pressure, blood glucose. Reduced blood flow to skin and digestive system

27. Endocrine glands Adrenal glands
Cortex: secretes corticosteroids. Involved in _________ balance, glucose balance, etc.

28. Endocrine glands
Pancreas
Located below liver in abdomen

29. Endocrine glands Pancreas
Recall Islets of Langerhans. Make insulin and glucagon. Together, regulate glucose in blood.

30. Endocrine glands
Gonads (testes and ovaries)

31. Endocrine glands Gonads (testes and ovaries) Make steroid sex hormones
Testosterone, estradiol, progesterone (discussed)

32. Endocrine disruptors
Chemicals from environment that can interfere with endocrine system
Chemical structures similar to those of some hormones
Examples: pesticides, herbicides, etc.

33. Endocrine disruptors Ex, Lake Apopka, Florida
1980: chemical spill of pesticide DDT
Affected development of male alligators (lower testosterone levels, smaller __________ size, anatomical defects)

34. Endocrine disruptors Human concerns: Puberty of females coming earlier
Many possible causes, but endocrine disruptors may be involved

35. Endocrine disruptors Ex, Michigan 1973
Chemical called PBB accidentally mixed into cattle food
Meat and dairy products reached 4,000 people
Daughters of women exposed surveyed in late 1990s
Menstruation started ______ years earlier in daughters of exposed women