Female Reproduction - Dr. Nicholas J.D. Wright, PhD

What are the principal female reproductive organs?

Ovaries

Fallopian tubes

Uterus

Vagina

What is the role of the ovaries each month?

One ovary releases one ovum (egg) into fallopian tube until menopause

What happens to the egg in the fallopian tube if fertilized?

Implants in wall of uterus and develops in fetus and supporting placenta

What are primordial follicles and when are they developed?

Contain primary oocytes, are present before birth

T/F: Ovaries are active from the time of birth

FALSE - stay dormant until puberty

Where is GnRH produced and what does it feed back on?

Produced by hypothalamus

Stimulates FSH and LH production

Where are FSH and LH produced?

Anterior pituitary

How are oogonia differentiated into a primary oocyte?

Mitosis differentiation

When does the first mitotic division that converts a primary oocyte to a secondary oocyte occur?

Begins in utero, completed prior to ovulation

When does the second mitotic division occur and what does it form?

Occurs after puberty and completes before fertilization

Forms the ovum

Roughly how many days does the typical female hormonal cycle last?

28 days

Ovarian changes rely on what hormones, and when are the hormones secreted?

FSH and LH, not secreted until pubtery

What do granulosa cells secrete during childhood to maintain the oocytes?

Oocyte-maturation inhibiting factor

(this keeps the ova in prophase)

Follicles develop from what hormones after puberty?

FSH and LH

Which follicle becomes dominant, and why is it thought to only be the only one?

The dominant follicle has more granulosa cells, more estrogen, expresses more FSH receptors, and survives FSH drop due to estrogen feedback

(it is thought the largest one has these features and becomes dominant)

Where are granulosa cells found and what do they produce?

Found in the ovaries

Secrete inhibin and estrogen

Where are theca cells found and what do they procude?

Found in the ovaries

Produce androgens

What produces progestin?

Corpus luteum

How is the corpus luteum formed?

After ovulation, remaining granulosa cells and outer theca cells leutinize and become the corpus luteum (driven by LH)

What is the function of the corpus luteum?

Maintain estrogen and progesterone necessary for implantation in the absence of FSH and LH bc of estrogen/progesterone feedback

What happens to the corpus luteum if fertilization does not occur?

Degenerates (involution) and becomes the corpus albicans

What causes degradation of the corpus luteum (hormonally) in the absence of fertilization?

Lutein cells secrete inhibin to inhibit FSH; lack of gonadotropins cause degradation

What happens to the corpus luteum if fertilization does occur?

Implanted egg secretes hCG which substitutes for LH (neg fb from estrogen and progesterone) which maintains the corpus luteum ~2-4 months into pregnancy

If fertilization does not occur, what ultimately starts the beginning of the cycle again and causes menstruation?

Estrogen, progestin, and inhibin levels decrease when corpus luteum breaks down -> no neg fb on anterior pituitary -> FSH and LH increase again and cause menstruation

In normal, non-pregnant females what is the only source of estrogen?

The ovaries

Which form of estrogen is the most biologically active?

estradiol

T/F: steroid hormones are made and released on demand

True

What cells in the female secrete anti-mullerian hormone?

Granulosa cells

The amount of anti-mullerian hormone secreted directly correlates to whaat?

Number of potential follicles available

Anti-mullerian hormone levels in females can be used as an indicator for what?

Menopause when the female has no remaining oocytes or granulosa cells

A surge of what hormone induces ovulation?

LH

What causes the LH surge?

Increased plasma concentrations of estradiol in late follicular phase change estrogen to POSITIVE FB on LH, induces LH surge

When does ovulation normally occur?

~ day 14 (middle of cycle)

Approximately how many days does it take for an egg to be fertilized after ovulation, and where does this occur?

About 1 day in the fallopian tube

About how many days does it take for implantation in the uterus, and what has the cell become at this point in the cycle?

5-7 days for uterus implantation

Divides many times to become a multicellular blastocyst

LH surge causes shift in producing what two main hormones during ovulation?

Switches from mainly estrogen production to progesterone production

What disease states are well known for affecting the hormonal regulation of the menstrual cycle?

Hyperprolactinemia

PCOS

Progesterone is required for what part of the female reproductive tract to function?

Endometrium

How is the female orgasm affected by estrogen?

estrogen levels possibly synchronize to coincide with ovulation for fertilization

T/F: The female orgasm required bothphysical and psychological factors with integration in the sacral SC

True *foreplay*

What are myoepithelial cells in the breasts and what are they responsible for?

Contractile cells that eject milk with suckling

What type of glands do the breasts contain?

Exocrine glands of compound alveolar type

Estrogen secreted during puberty causes significant growth of what part of the breasts?

Ducts

Progesterone secretion during luteal phase of stimulates growth of what part of the breasts?

Alveoli (to prepare for potential pregnancy)

What hormones are necessary for proper breast development?

1. Estrogens

2. Progestins

3. Prolactin

4. Human placental lactogen (if implantation occurs)

How many days before/after ovulation should coital activity occur for successful impregnation?

~4-5 days before/1 day after

How long is an ovum available for after ovulation?

24 hours

What is the rhythm method and how is it affective?

Don't have raw sex while you're fertile

Only works if cycle is 'reliable' (requires temp monitoring to predict ovulation bc body temp increases)

Generally speaking how to OCPs work?

Orally supplement sex steroids (estrogen + progestin) to inhibit LH surge

Know that physical barriers can be combined with spermicide for increased efficacy (IUDs)

Know that physical barriers can be combined with spermicide for increased efficacy (IUDs)

How does the 'morning after pill' work?

Prevents implantation if any fertilized ova are present