1. Organismal Development Part 4
Female Animals

2. Female Reproductive Anatomy
Oviduct
Ovaries
Follicles
Corpus luteum
Uterine wall
Uterus
Endometrium
Cervix
Vagina

3. Oogenesis in the ovaries
Ovary
Primary germ cell
in embryo
Differentiation
Oogonium
in ovary
Oogonium
Mitotic
division
Primary
oocyte
within
follicle
Primary
oocyte
Completion of meiosis I
and onset of meiosis II
Growing
follicle
Secondary
oocyte
First polar body
Ovulation
Entry of sperm
triggers
completion
of meiosis II
Mature follicle
Ruptured
follicle
Second polar body
Ovum
Ovulated
secondary oocyte
Corpus luteum
Degen-
erating corpus luteum

4. Female Reproductive Cycle in Humans
Control by hypothalamus
Inhibited by combination of
estrogen and progesterone
Hypothalamus
Stimulated by high levels
of estrogen
GnRH
Anterior pituitary
Inhibited by low levels of
estrogen
FSH LH
Pituitary gonadotropins
in blood LH
FSH
FSH and LH stimulate
follicle to grow
LH surge triggers
ovulation
Ovarian cycle
Corpus
luteum
Degenerating
corpus luteum
Growing follicle
Mature
follicle
Follicular phase
Ovulation
Luteal phase
Estrogen secreted
by growing follicle in
increasing amounts
Progesterone and
estrogen secreted
by corpus luteum
Ovarian hormones
in blood
Peak causes
LH surge
Estrogen
Progesterone
Estrogen level
very low
Progesterone and estro-
gen promote thickening
of endometrium
Uterine (menstrual) cycle
Endometrium
Menstrual flow phase
Proliferative phase
Secretory phase
Days 5 10 14 15 20 25 28

5. Fertilization and Implantation if pregnancy occurs
Cleavage starts
Cleavage continues
Ovary
Fertilization occurs
The blastocyst implants
Uterus
Ovulation
Endometrium
From ovulation to implantation