Female Reproductive Physiology. Role of the human female The female human has the following roles in...
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Transcript of Female Reproductive Physiology. Role of the human female The female human has the following roles in...
Role of the human female
• The female human has the following roles in reproduction – Production of the egg – Ovulation – Implantation of the egg – Pregnancy – Birth – lactation
Granulosa CellFSH
cAMP
DNA transcription
Via PKA
Enzyme(aromatase)
• The granulosa cells do not have the enzymes to convert progesterone into androstenedione so instead must receive androstenedione from the thecal cell.
• there is an interaction between the thecal and granulosa cells in order to produce estrogens.
LH FSHLDL
via cAMP
Cholesterol
Pregnenolone
Androstenedione
Thecal Cell
Estradiol
Granulosa Cell
INTO THE BLOOD
via cAMP
During the Follicular Phaseestradiol.
LH
FSH
LDL
via cAMP
Cholesterol
Pregnenolone
Androstenedione
Thecal Cell
Estradiol
Granulosa CellINTO THE BLOOD
Progesterone
Cholesterol
Pregnenolone
Progesterone
via cAMP
LHLuteal phase
Negative and Positive Feedback In females, the hypothalamic-pituitary axis is controlled by both negative and positive feedback, depending on the phase of the menstrual cycle
Progesterone
Collagenaseprostaglandins
Hyperemia
Swelling of follicle
Breakdown of wall
Stigma degeneration
Rupture and
ovulation
EstrogensEstrogen is the word defining the family of sex hormones that include estradiol, estriol and estrone. They are secreted in varying amounts by the ovary but all have similar effects (though different potencies).
Estrogens (at Puberty)
Size of Reproductive
organs
Initiation of Breast
development
Vaginal Epithelium
Infection -resistant
Epiphyseal Fusion
Histological Changes in Uterine cells
Estrogen(> puberty)
no. and activity Of ciliated cells
At oviduct
Protein synthesis
Further breast development
Ovarian and Menstrual
function
Subcutaneous Fat deposition
ProgestinsTwo hormones that come under the umbrella of progestins are released by the ovary, progesterone and 17--hydroxyprogesterone. The former is secreted in a much greater amount and it is convention to put both under the name progesterone.
Progesterone
Uterine endometrium
Ovulation
Alveoli cells Or breast
↓Uterine excitability During pregnancy
Puberty and Menopause
• At Puberty: – GnRH activity increases – Eventually leads to ovarian activity – Increased estrogen levels stimulate
reproductive organ development. • At Menopause
– Cessation of the ovarian cycle – Decreased estrogen secretion.
Endocrinology of Pregnancy
In order to understand pregnancy you must accept the fetus, placenta and mother all as one unit. This section will discuss the hormone interactions within this unit and the reasons underlying these changes.
Human Chorionic Gonadotropin It is produced by the embryo prior to implantation and after implantation is secreted by the syncytiotrophoblast cells in the intravillous space.hCG can be detected in the serum or urine 7-8 days before the expected menses and is the earliest detector of pregnancy. In fact some can now measure hCG levels 2 days after fertilization has taken place.
hCG Corpus Luteum
EstrogensProgesterone
Male Fetus
The Placenta• The placenta is a
specialized organ – Controls exchange between
maternal and fetal blood
• Capillaries from umbilical cord embed in placenta – Called placental villi – Allow for the exchange of
blood.• allow nutrient uptake, waste
elimination, and gas exchange via the mother's blood supply.
Progesterone-
Endometrial cells Of uterus
And Inhibition of myometrium.
Maintains pregnancy
Cervical Plug?? Final breast
development
Estrogens
Prepare body for Parturition(myometrium) Development
Of Breast
Inhibits Milk production
(with progesterone)
Initiator of Parturition ???
Human Placental Lactogen (hPL)
Growth Hormone Effects ??? On breast
Decreases maternal Insulin sensitivity
More glucose available For fetus
Example:LMP = 31 May 2011
+1 year = 31 May 2012-3 months = 31 February 2012+7 days = 7th February 2012
Diet/Nutrition
• demand for carbohydrates, proteins, iron, calcium (Vit D), folate (neural), Vitamin K (clotting factors)
Insulin and glucose levels
• Must supply adequate levels of glucose to fetus
• Mother develops hyperglycemia between meals and when sleeping – Increases as pregnancy continues
• Increase of placental hormones increase insulin resistance – Insulin levels rise
Parturition
Role of oxytocin
Smooth muscle cell
Oxytocin
IP3 & DAG Ca2+
Contraction
Delivery of the fetus, occurs approximately 40 weeks after the onset of the last menstrual period.
The mechanism of parturition is unclear, although roles for estrogen, progesterone , cortisol, oxytocin, prostaglandins, relaxin, and catecholamines have been proposed.
Initiation of Parturition
There is still much controversy and discussion over the mechanisms involved in the initiation of the birthing process. It may be due to a decrease in progesterone levels, an increase in circulating CRH or an increase in estrogen levels, or all three.
CRH
Hypothalamus
Placenta
Posterior Pituitary
Uterus
Fetus
oxytocin
oxytocin
pgs
Neural reflex
oxytocinContractions
of uterus
STRESS