Hormones are chemical messengers released by endocrine glands that cause changes in other parts of the body. The endocrine system works with the nervous system to maintain homeostasis through negative feedback loops. Key glands include the pituitary, thyroid, pancreas, ovaries and testes. Hormones regulate important bodily functions like growth, reproduction, metabolism, and temperature control.

1. 2006-2007 Endocrine System Hormones Reproduction

2. Hormones Why are hormones needed? chemical messages from one body part to cells in other parts of body communication needed to coordinate whole body maintaining homeostasis energy production growth development maturation reproduction growth hormones

3. Endocrine System Endocrine system releases hormones glands which secrete chemical signals into blood chemicals cause changes in other parts of body slow, long-lasting response growth hormones sex hormones response hormones metabolism hormones and more….

4. Regulation by chemical messengers Hormones released by endocrine glands axon endocrine gland Receptor sites target cell receptor molecules hormone carried by blood neurotransmitter

5. Glands Pituitary many hormones: master gland Thyroid thyroxine Pancreas Insulin glucagon Ovary Estrogen Progesterone Testes Testosterone

6. Body Regulation Nervous system & Endocrine system work together hypothalamus “ master nerve control center ” receives information from nerves around body about internal conditions communicates with pituitary gland “ master gland ” releases many hormones sexual development, growth, milk production, pain-relief hormones hormones

7. Maintaining homeostasis hormone 1 lowers body condition hormone 2 gland specific body condition raises body condition gland Feedback high low

8. Negative Feedback Response to changed body condition every time body is high or low from normal level a signal tells the body to make changes that will bring body back to normal level once body is back to normal level , signal is turned off hormone 1 lowers body condition gland specific body condition high

9. Controlling Body Temperature nerve signals sweat nerve signals brain body temperature shiver brain dilates surface blood vessels constricts surface blood vessels Nervous System Control Feedback high low

10. Regulation of Blood Sugar blood sugar level (90mg/100ml) insulin body cells take up sugar from blood glucagon Feedback Endocrine System Control pancreas pancreas high low

11. Negative Feedback Negative feedback every time body is high or low from normal level a signal tells the body to make changes that will bring body back body temperature control of blood sugar

12. Sex & Growth Hormones Large scale body changes how do they work turn genes on start new processes in the body by turning genes on that were lying “dormant”

13. Pituitary gland hormones Sex & reproductive hormones FSH follicle stimulating hormone stimulates egg & sperm production LH luteinizing hormone stimulates ovaries & testes prepares uterus for fertilized egg hormones hormones

14. Reproductive hormones Testosterone from testes sperm production & secondary sexual characteristics Estrogen from ovaries egg production, preparing uterus for fertilized egg & secondary sexual characteristics

15. Sperm production over 100 million produced per day! ~2.5 million released per drop! Male reproductive system

16. spermatocytes seminiferous tubule sperm

17. Male reproductive system Testes & epididymis sperm production & maturation Glands seminal vesicles, prostate, bulbourethal produce seminal fluid nutrient-rich

18. Male reproductive system Testicles (Testes) produces sperm & hormones Scrotum sac that holds testicles outside of body Vas deferens tubes for sperm to travel from testes to penis Prostate Produces nutrient rich fluid to feed & protect sperm

19. Female reproductive system

20. Female reproductive system Ovaries produces eggs & hormones Uterus nurtures fetus; lining builds up each month Oviduct (Fallopian tubes) tubes for eggs to travel from ovaries to uterus Cervix opening to uterus, dilates 10 cm for birthing baby Vagina birth canal for birthing baby

21. Female reproductive system

22. Egg maturation in ovary releases progesterone maintains uterus lining produces estrogen

23. Menstrual cycle LH FSH estrogen progesterone lining of uterus egg development ovulation = egg release corpus luteum 0 7 14 21 28 days Controlled by interaction of 4 hormones FSH & LH estrogen progesterone

24. Female reproductive cycle pregnancy maintains uterus lining Feedback estrogen egg matures & is released (ovulation) builds up uterus lining FSH & LH progesterone progesterone fertilized egg (zygote) HCG corpus luteum breaks down progesterone drops menstruation maintains uterus lining GnRH pituitary gland hypothalamus corpus luteum ovary no yes corpus luteum

25. Female hormones FSH & LH released from pituitary stimulates egg development & hormone release peak release = release of egg (ovulation) Estrogen released from ovary cells around developing egg stimulates growth of lining of uterus decreasing levels causes menstruation Progesterone released from “corpus luteum” in ovaries cells that used to take care of developing egg stimulates blood supply to lining of uterus decreasing levels causes menstruation

26. Fertilization

27. Any Questions?? 2006-2007

28. What do they do? Maintain homeostasis blood sugar level temperature control Start a new process growth fetal development sexual development Body Temperature