1. Animal Reproduction

2. Modes of Reproduction 2 modes: asexual reproduction fission budding
regeneration
parthenogenesis

5. Modes of Reproduction sexual reproduction hermaphroditism
fertilization
internal and external
hermaphroditism
sequential hermaphroditism

6. Reproductive Systems
simplest animals do not have gonads (produce gametes)
polychaetes’ gametes develop from undifferentiated cells lining the coelom
more complex animals have gonads and a system of ducts and glands

7. Reproductive Systems non-mammalian vertebrates possess a cloaca
mammals have separate openings for each system

8. Spermatogenesis
sperm structure:
head
acrosome
midpiece
tail

10. Oogenesis
production of an ovum
occurs in the ovaries

12. Regulation of Male Reproductive System

13. Regulation of Female Reproductive System
pattern of hormone secretion is cyclic
menstrual cycle
endometrium is shed if no implantation occurs (menstruation)
estrous cycle
endometrium is reabsorbed

14. Menstrual Cycle average length is 28 days refers to changes in uterus
1. Menstrual flow phase
menstrual bleeding
2. Proliferative phase
endometrium regenerates
Secretory phase (about 2 weeks long)
glands in endometrium secrete glycogen

15. Ovarian Cycle 1. Follicular phase 2. Luteal phase
several follicles begin to grow
ends in ovulation
2. Luteal phase
follicle cells remaining after ovulation develop into corpus luteum

17. Hormonal Control Follicular phase
FSH and LH secreted in response to GnRH
follicle cells have only FSH receptors
follicle cells secrete estrogens
slow rise in estrogen levels, keeping FSH and LH levels steady

18. Hormonal Control
positive feedback- sharp increase in estrogens cause sharp increase in FSH and LH (increases GnRH release)
LH receptors develop on follicle cells
high LH causes final follicle maturation
ovulation occurs about 1 day after LH surge

19. Hormonal Control Luteal phase
LH stimulates follicle cells to form corpus luteum
corpus luteum releases progesterone and estrogens
negative feedback- production of progesterone and estrogen inhibits release of LH and FSH

20. Hormonal Control ovarian cycle and menstrual cycle are sychronized
corpus luteum disintegrates in 8-10 days, releasing negative feedback
FSH production resumes and the cycle continues over again
ovarian cycle and menstrual cycle are sychronized

21. Hormonal Control follicular phase and proliferative phase are linked
estrogens cause endometrium to thicken
uterus is prepared for implantation before ovulation
luteal phase and secretory phase are linked
estrogens and progesterone maintain endometrial lining

22. Hormonal Control
rapid drop in ovarian hormones after corpus luteum disintegrates causes arteries in endometrium to spasm, depriving endometrium of blood
menstruation results

26. Menopause cessation of ovulation and menstruation
ovaries lose responsiveness to FSH and LH