Lecture 32- Female Reproductive System Flashcards
What are the function of ovaries?
Primary sex organ that produce egg each month and sex hormones
What are the function of oviducts?
Conducts egg Site of fertilization
What are the functions of The Uterus?
Houses the developing the embryo and fetus.
What are the endometrium, myometrium, and perimetrium?
Endo-The inner lining of the uterus Myo- thick layer of muscle Peri- covering of uterus
What is the vagina?
Thick layer of muscle in uterus
Mitosis of primordial oogonia occurs in x until midgestation, where it peaks at of y million oocytes and then ceases. then there is progressive loss of oocytes approximately z oocytes However only - 400 follicles ovulate in women
Mitosis of primordial oogonia occurs in female fetus until midgestation (peak of 7 million oocytes and then ceases, then there is progressive loss of oocytes approximately 400,000 oocytes Howebee only - 400 follicles ovulate in women
The oocyte begins its first meiotic division in p wheee it stops in z.
It begins in uterine, where it ceases at Prophase I (primary oocyte)
When does the primary oocyte divide meiotically?
During puberty, producing the first polar body and a secondary oocyte. The secondary oocyte begins meiosis II and stops at metaphase II
When does the primordial follicle differentiate into the primary follicle?
After the start of puberty. Then The follicle starts growing and maturing, at the same time secondary oocyte forms.
When does the oocyte ovulate (leave the follicle?
When the follicle matured and the secondary oocyte is formed.
When does the secondary oocyte continue and finish meiosis II?
When the sperm fertilizes it, forming secondary polar body/
What happens to the follicle after ovulation?
It differentiates into the corpus luteum.
What is the primary follicle able to produce?
The sex harmone estrogen
What is the secondary follicle able to produce?
Both the sex hormones estrogen and progesterone
How long does it take for the corpus luteum to disintegrate?
2 weeks
What are follicles made out of?
Oocyte, granulosa cells, and thecal cells.
Changes in the ovary are due to changing levels of x from the y
FSH and LH from the anterior pituitary
The follicular phase is dependent on which hormone?
FSH
The corpus luteum is dependent on which harmone?
LH
Draw the hypothalamic pituitary ovarian axis
When does Estrogen act as +ve feedback mechanism on GnRH ,LH and FSH?
When the levels of Estrogen are very high (before ovulation)
What are the 3 stages of the ovarian cycle?
- Follicular phase
- ovulation
- luteal phase
What are the 3 stages of the menstrual cycle?
- Proliferative phase
- Secretory phase
- menstruation
What causes Estrogen levels to increase gradually after Menses?
FSH levels leading to the development of the follicles (mainly primary follicle) which secrete Estrogen
this initially creates a -ve feedback mechanism on FSH and slightly on LH
What leads to the spike in LH levels and FSH levels on day ≈13, and why is the spike of LH much higher than FSH?
- Estrogen levels being very high.
- When estrogen levels are v high, a +ve feedback mechanism develops, increasing FSH and LH, further increasing Estrogne levels
- FSH doesn’t spike as high as LH because of inhibin present (from follicles)
What triggers ovulation?
A spike in LH at around day 14
For how many days is the corpus luteum liable?
14 days.
‘for eg, if a women’s menstrual cycle lasts 30 days, ovulation occurs at day 16
What is the name for the follicle that will ovulate?
Grafiian or vesticular
What causes menses (shedding of the endometrium)?
The drastic drop of the ovarian harmones ,mainly progesterone, and also estrogen
What causes the disintegration of the corpus luteum?
The deal in LH levels, more specifically FSH levels higher than LH
What triggers the start of the secretory phase?
Progesterone production; by corpus luteum.
What is a good indication, that is easily testable, that the luteal phase has started?
The spike in body temp of +0.5C
What is the proliferation stage influenced by?what occurs in the secretory stage?
Estrogen
What occurs during the secretory phase?
The endometrium secretes glycoproteins, proteins, etc to nourish the embryo.
The functional part of the endometrium is x% and the intact part of the endometrium is
2/3 (66%) functional 1/3 (33%) intact
True/ false
The harmones estrogen, progesterone, and inhibin have a -ve feedback mechanism on GnRH?
True
Why are there low levels of FSH during the luteal phase and what is the functional consequence of that?
Because of high inhibin levels. This ensures that no new follicles are recruited.
What is inhibin secreted by specifically?
Granulosa cells inside the follicles
T/False.
‘one follicle is recruited every menstrual cycle
False. Several are recruited. However, only one managed to ovulate and transition into corpus luteum. The others disintegrate beforehand
When does progesterone initially increase?
Towards the very end of the follicular phase, when 2ndary follicles appear (mature)
When does GnRH start to drop?
Right after luteal phase; due to the -ve feedback mechanism of progesterone starting to increase, while estrogen is decreasing to a level where it has -ve feedback (ultra high levels warrant a +ve feedback mechanism)
Which ovarian harmone does the corpus luteum mainly secrete?
Progesterone
How long does the follicular phase in a 28 day cycle, and what does it lead to?
Around 13 days
leads to the maturation of the Graafian follicle
When does estradiol peak?
Around day 12, 2 days b4 ovulation
The LH surge causes the oocyte to
Complete meiosis 1.
1° oocyte to 2°oocyte, and expulsion of it with the polar body
When do estrogen and progesterone levels start to drop?
At day 22; it will reach VERY LOW levels at day 28
Does the proliferative phase occur during the follicular or luteal phase?
- Follicular phase
- it is stimulated by the increase of estradiol (stratum functionale of the endometrium)
Which phase describes;
- endometrium becomes thick, vascular, and spongy in appearance
- uterine glands become engorged with glycogen, lipids, and proteins
- Endometrium ready to accept and nourish embryo
- and what causes these effects?
The secretory phase
increased estradiol and progesterone levels
An increase in z stimulates the development of the uterine glands
Progesterone
Describe the process of menstruation
- Arteries that supply the lining of the uterus restrict and the capillaries are weakened
- damaged vessels detach layers of turbine lining –> blood, mucus, and degenerative tissue to descend from the uterus
- Fibrinolysis- the breakdown of fibrin released from the dying cells- a clotting enzyme to prevent clotting
What is menarche?
Define amenorrhea
A condition where the female does not menstruate by the age of 16, or the uterine cycle is interrupted for more than 6 months (without pregnancy)
Is caused by ;
- non functional ovaries
- developmental abnormalities
- weight loss
- excessive excercise
Define menopause
The cessation of the menstrual cycle
occurs between the ages of 45-55
What are the female secondary sexual characteristics estrogen is responsible for?
- Less body and facial hair
- more fat beneath skin to give rounded appearance
- enlargement of pelvic girdle and cavity to give wider hips
Give examples of characteristics that require both estrogen and progesterone
- Breast development
- Maintaining the endometrium lining
- suppression-for GnRH
- inhibitopm of prolactin secretion
