1. Endocrine glands - ductless Hormones released to circulation  Specific to target tissues Endocrine control Neural control p.505

2. Endocrine glands

4. Pituitary (hypophysis) - vertebrates  Neurohypophysis (posterior) - from the floor of brain (infundibulum)  Adenohypophysis (anterior) from pocket of embryonic mouth cavity

5. Pituitary development

6. Hypothalmus AdenohypophysisNeurohypophysis oxytocin, ADH

7. ADH - Anti-diuretic hormone  increased permeability in collecting ducts Oxytocin - (mammals)  uterine contractions, milk ejection

8. Hypothalmus AdenohypophysisNeurohypophysis oxytocin, ADH LH, FSH, GH, prolactin, ACTH TSH

9. Adenohypophysis - LH - Lutenizing hormone FSH –Follicle stimulating hormone Prolactin - mammaries, behavior Neurohypophysis Oxytocin Reproductive hormones

10. Primary follicle oocyte Follicle cells Looking within the ovary… FSH - causes follicle to mature, grow Follicle cells secrete estrogen

11.  Estrogen promotes development of endometrium  promotes LH release when estrogen is high – positive feedback Estrogen

13. Surgical photos capture ovulation occurring

14. Induced ovulators LH not promoted by estrogen Act of breeding stimulates pituitary gland to release LH  Llamas: Levels of LH in the blood begin to rise 15 minutes after the beginning of breeding.

15. Follicle remains as corpus luteum (mammals, reptiles, sharks)  releases progesterone and estrogen  Progesterone continues growth of endometrium blood vessels, decrease contractions  Promotes egg layers, shell in reptiles Follicle remains

16. If fertilization: blastocyst chorionic gonadotropin which maintains c. luteum Eventually, placenta takes over progesterione prod’n Fertilization corpus luteum CG

17.  Progesterone and estrogen also inhibit FSH, LH and prepare mammary glands  At birth, decreased levels of progesterone promotes oxytocin, prolactin

18. Feedback from mammaries  Stimulates prolactin, oxytocin release  Inhibits GnRH and FSH p.685

19. Suckling feedback allows for embryonic diapause  Mother has blastocyst, yet prolactin inhibits corpus luteum, thus progesterone Marsupials Kangaroo is pregnant Should I develop or not?

20. After weaning (or young dies), suckling decreases, blastocyst can implant  marsupial breeding marsupial breeding Marsupials

21. Marsupials - most development during lactation  Easier to terminate parental care Placentals cannot readily terminate vs.