11-8-06
•
For next time: read thoroughly the sections on labor
& delivery; Lactation; Contraception
•
Ch 15
•
Gall Bladder case study.
•
Quick survey:
─
Approx score last exam (nearest 10 pts)
─
Did you study in a group?
─
Did you study at least 6 hrs/week every week b/t exams
(not average)?
─
Did you ensure that you could fulfill all objectives?
Female Reproductive System
Before we get going, take 1 min and compare and
contrast M & F systems:
• M: continuous Sperm Prod. Vs F – 1 egg/month
• M: releases gamete vs. F: retains & nurtures fertilized
gamete
─ F: regulates environment over cycle
─ F: Hormones control release of egg
─ F: Egg cell cycle control complex (long) & 1 ovum / oogonia
Figure 17-13
Path for spermatozoa
ejaculated into the
female reproductive tract:
Vagina  cervix 
uterus  fallopian tube
Path for egg:
ovaries fallopian tube
(combined actions of
fimbrial contractions and
the oviduct’s “ciliary
escalator.”)
Question #2: Describe the various stages
from oogonium to mature ovum
• Oogonia  Mitosis &
Differentiation Primary
oocyte; meiotic arrest
• Follicles (1 egg & supporting
tissue)
─ Primordial follicle = egg +
granulosa
─ 1˚ = larger egg + zona
pelucida (layer of material),
proliferation of ganulosa
─ Pre-antral follicle multiple
granulosa layers,
─ Antral follicle antrum (fluidfilled space) forms
Female Hormonal Control
• Menstrual Cycles
─ As W/males, HPA control
GnRH  FSH, LH
release  sex hormones
Long and short loop
feedback
─ Resulting in
Cyclical gamete release
Preparation of uterus for
implantation, nurturing
If not, then menstruation
Note: Fig 17-18 Summarizes the “BIG
PICTURE” tying everything together
between HPA, Ovaries and Uterus
The 1st portion of the questions covers
ovarian events of the menstrual cycle;
The later questions, cover uterine
events linking them to ovarian cycle
Q # 4: Name 3 hormones produced by the
ovaries and name the cells that produce
them
• Estrogen (s) --- Granulosa Cells (follicular
phase); Corpus luteum (luteal phase)
• Progesterone --- granulosa and theca (little)
before ovulation; corpus luteum (luteal phase)
• Inhibin --- Granulosa Cells & Corpus luteum
Q #6: What are the analogies between the
granulosa cells and the sertoli cells and between
the theca cells and the Leydig cells?
• Sertoli and granulosa
─ support gametes
─ Respond to FSH
─ secrete chemicals that directly stimulate gamete
development
─ Inhibin
• Leydig and Theca
─ Both secrete androgens
─ Both respond to LH
─ Secretions of both feed back to hyp and AP
Q #7: List the effects of FSH on the follicle
• 1st wk: levels of FSH,LH low, but enough that
─ FSH stimulates follicle dev.; granulosa cells to divide and
produce estrogen; Estrogen acts as an auto-/paracrine
agent  more estrogen secretion
─ LH stimulates theca cells to release androgens needed by
granulosa cells for estrogen production
New edition has error in
this figure... FSH & LH
switched (17-19)
Q #8: Describe the effects of
estrogen and inhibin on
gonadotropin secretion ...
•
Early & Mid:
─
Estrogen short loop to AP
inhibits FSH & LH release
 Decrease in FSH & LH at
this time causes atresia of
non-dominant follicles
•
─
Estrogen long loop to hyp:
inhibits GnRH releases
─
Inhibin: inhibits mainly FSH
Late: everything changes!!!
─
High levels of estrogen
enhance AP sensitivity to GnRH
(mainly LH-releasing cells) 
LH surge  ovulation
Q # 9: List the
effects of the LH
surge on the egg
and the follicle
He he he... Couldn’t
have said it better
myself:
Q #10: What are the effects of the sex steroids and
inhibin on gonadotropin secretion during the luteal
phase
• IN THE PRESENCE OF ESTROGEN high
progesterone suppresses GnRH and
gonadotropin release
• Inhibin: feeds back to AP and inhibits FSH
release
• (Fig 17-18)
Q #11: Describe the hormonal control of the CL in
a non-pregnant and in a cycle when pregnancy
occurs
• No pregnancy: low LH keeps CL going for ca. 2
weeks; sensitivity drops off over time and CL
degenerates  lower estrogen/progesterone 
menstruation & releases feedback suppression
of gonadotropin release
• W/ /pregnancy: hCG  from placenta sustains
CL for about 2 mos. So that it secretes estrogen
and progesterone for the uterus.
Q # 12: What happens to the sex steroids
and the gonadotropins as the CL
degenerates?
• Sex steroid levels drop off (uterine
effects?)
• Alleviates negative feedback inhibition of
gonadotropin release which increases a
bit, thus triggering the development of a
new set of follicles
Q # 13: Compare the phases of the menstrual
cycle according to uterine and ovarian events
• This is part of figure 17-22
Q #14: Describe the effects of estrogen and
progesterone on the endometrium, cervical
mucous, and myometrium
• Estrogen (follicular phase): proliferation of
endometrium; development of myometrium;
receptors for progesterone (endometrial cells)
• Estrogen & Progesterone (luteal phase):
─ Progesterone inhibits myometrial contractions
─ Increase glandular activity of endometrium
─ Increase glycogen content of endometrium
─ Increase vascularization of endometrium
─ Changes cervical mucous from watery and abundant
to sticky viscous plug (bacterial blockade)
Q #15: Describe the uterine events
associated with menstruation
• Drop in estrogen and progesterone 
prostaglandins  vasoconstriction  lack of
oxygen/nutrients leads to degeneration of
endometrium
• Myometrium begins undergoing contractions
• Later  vasodilation  bleeding
Pregnancy
• Fertilization of Egg = Zygote Formation
• Cleavage turns zygote into Conceptus
─For now, composed of all totipotent cells
─For 3-4 d, conceptus stuck in fallopian tube b/c
of estrogen mediated contraction of opening to
uterus
Pregnancy
• ~ d 17:
─progesterone relaxes opening to uterus
─conceptus released floats freely for ~ 3 d.
─differentiates; by the end its cells are no longer
totipotent
─Becomes a Blastocyst
Outer layer = trophoblast
Inner Cell mass --> eventually becomes embryo
@ 2 months embryo = fetus
Pregnancy
• ~ d 21: implantation occurs
─Sticky Trophoblast cells
Proliferative when in contact w/ endometrium
Secrete proteolytic enzymes, paracrine agents:
facilitate entry of blastocyst into endometrium
Secrete Chorionic Gonadotropin (CG)
• Remember CG Maintains CL until the placenta is
formed
─Estrogen and Progesterone to maintain
endometrium
Pregnancy
• Initially, endometrial cells
directly nourish bastocysts
• After the first few weeks
the Placenta takes over
nutrition, environmental
control
Q # 24: State the sources of estrogen and
progesterone during the different stages of
pregnancy. What is the dominant estrogen of
pregnancy and how is it produced?
• Estrogen
─ 1st Corpus luteum, after ca. 60-80 d, Placenta becomes
main source; promotes myometrial development
─ Main estrogen = Estriol
• Progesterone
─ 1st Corpus luteum, after ca. 60-80 d, Placenta becomes
main source
─ Inhibits contractions
Q #25: What is the state of gonadotropin secretion
during pregnancy and what is the cause?
• CG
─ High for 2-3 months when it stimulates est. & prog.
from CL
─ Then placenta takes over
• LH/FSH levels
─ Low throughout pregnancy
─ B/c GnRH secretion is inhibited by high levels of
progesterone in presence of estrogen
─ Prevents development of additional follicles/eggs