09a reproductive hormones-2010 update

1,106 views

Published on

Published in: Health & Medicine, Technology
0 Comments
1 Like
Statistics
Notes
  • Be the first to comment

No Downloads
Views
Total views
1,106
On SlideShare
0
From Embeds
0
Number of Embeds
11
Actions
Shares
0
Downloads
0
Comments
0
Likes
1
Embeds 0
No embeds

No notes for slide

09a reproductive hormones-2010 update

  1. 2. Male Reproductive Hormones <ul><li>androsterone </li></ul><ul><li>testosterone </li></ul>
  2. 3. Male Reproductive Hormones <ul><li>both hormones are released from testes </li></ul>
  3. 4. Testes Cells <ul><li>Leydig interstitial cells synthesize hormones </li></ul><ul><li>Sertoli cells synthesize sperm </li></ul>
  4. 5. Testosterone Role <ul><li>stimulates spermatogenesis (life time process) </li></ul><ul><li>develops male characteristics at puberty </li></ul><ul><li>increased secretion of body oils </li></ul><ul><ul><li>commonly associated to body odour </li></ul></ul>
  5. 6. Gonadotropic Hormones <ul><li>gonadotropic hormones regulate gonad development (male and female) </li></ul><ul><ul><li>produced in the pituitary; released upon hypothalamus signal </li></ul></ul><ul><li>follicle stimulating hormone ( FSH ) </li></ul><ul><li>luteinizing hormone ( LH ) </li></ul>
  6. 7. Male Gonad Development <ul><li>hypothalamus secretes gonadotropin-releasing hormone ( GnRH ) </li></ul><ul><li>pituitary gland releases FSH & LH </li></ul><ul><li>LSH stimulates Sertoli cells to form sperm </li></ul><ul><li>FSH stimulates Leydig cells to secrete testosterone </li></ul>
  7. 8. Male Gonad Development <ul><ul><li>Role of testosterone: </li></ul></ul><ul><li>promotes Sertoli cell activity </li></ul><ul><ul><li>increases sperm cell production </li></ul></ul><ul><ul><li>four sperm per germ cell </li></ul></ul><ul><li>negative feedback on hypothalamus </li></ul>
  8. 9. hypothalamus pituitary testes Sertoli cells Leydig cells GnRH FSH LH testosterone sperm production
  9. 10. Female Reproductive System <ul><li>estrogen </li></ul><ul><li>progesterone </li></ul>
  10. 11. Female Reproductive System <ul><li>both produced in the ovaries </li></ul>
  11. 12. Ovary Follicle Cells <ul><li>primary oocyte fertilized by sperm </li></ul><ul><li>granulosa cells provide nutrients for primary oocyte </li></ul>
  12. 13. Female Reproductive System <ul><li>comparatively more complicated than male reproductive system </li></ul><ul><ul><li>monthly cycle until menopause (~12 to 50 yrs) </li></ul></ul><ul><ul><li>one ovum produced per germ cell </li></ul></ul><ul><li>female hormones responsible for oogenesis and ovulation </li></ul>
  13. 15. Menstrual Cycle <ul><li>menstruation (flow phase) </li></ul><ul><ul><li>sloughing of endometrial cells </li></ul></ul><ul><ul><li>no ovum fertilization </li></ul></ul><ul><ul><li>estrogen and progesterone levels low </li></ul></ul><ul><li>follicular phase </li></ul><ul><ul><li>follicle maturation </li></ul></ul><ul><ul><li>estrogen secretion by granulosa cells </li></ul></ul>
  14. 16. Menstrual Cycle <ul><li>3. ovulation </li></ul><ul><ul><li>ovum leaves ovary </li></ul></ul><ul><ul><li>granulosa cells become corpus luteum </li></ul></ul><ul><ul><li>corpus luteum begins to secrete progesterone </li></ul></ul><ul><ul><li>estrogen levels decrease </li></ul></ul>
  15. 17. Menstrual Cycle <ul><li>4. luteal phase / secretory stage </li></ul><ul><ul><li>corpus luteum secretes progesterone & estrogen </li></ul></ul><ul><ul><li>progesterone encourages endometrium development </li></ul></ul>
  16. 19. Female Gonad Development <ul><li>GnRH, FSH and LH involved </li></ul><ul><li>hypothalamus secretes gonadotropin-releasing hormone ( GnRH ) </li></ul><ul><li>pituitary gland releases FSH & LH </li></ul><ul><li>FSH matures follicle </li></ul><ul><li>LH causes ovulation and causes corpus luteum maturation </li></ul>
  17. 20. hypothalamus pituitary ovaries follicle corpus luteum GnRH FSH LH progesterone some estrogen estrogen 1 2 ovulation
  18. 21. Menopause <ul><li>ovaries lose responsiveness to FSH and LH </li></ul><ul><li>usually occurs between ages 46 and 54 </li></ul><ul><li>most other mammals do not undergo menopause </li></ul><ul><ul><li>thought to allow human females to take care of grandchildren rather than continue to reproduce </li></ul></ul>

×