before pregnancy

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Female Physiology Before Pregnancy

and Female Hormones

By: Ma. Theresa Stephanie B. Yee

Medicine 1B



Female's internal reproductive organs

Vagina

a. is a muscular, hollow tube that extends from the vaginalopening to the uterus.

b. The vagina is about 3 to 5 inches (8 to 12 centimeters) longin a grown woman. Because it has muscular walls, it can expand andcontract.

c. The vagina connects with the uterus at the cervix



fallopian tubes - connect the uterus to the ovaries.

- about 4 inches and as wide as a piece of spaghetti.

Ovaries

a. 2 oval-shaped organs that lie to the upper rightand left of the uterus.

b. produce, store, and release eggs into thefallopian tubes in the process called ovulation.

c. measures about 1 1/2 to 2 inches (4 to 5 centimeters) in a grown

woman.

d. produce female sex hormones such as estrogen and progesterone.



Anatomy of the Female sex Organs



Female Hormonal System

3 hierarchies of hormones:

1.) a hypothalamic releasing hormone,

gonadotropin releasing hormone (GnRH)2.) the anterior pitiutary sex hormones, follicle-

stimulating hormone (FSH) and luteinizing

hormone (LH)

3.) the ovarian hormone, estrogen and

progesterone



Monthly Ovarian cycle; Function of the

GnRH

Female Monthly Sexual Cycle ( Menstrual Cycle)

- is the monthly rhythmical changes in the

rates of secretion of the female hormones andcorresponding physical changes in the ovaries

and other sexual organs.

- the duration of the cycle averages 28 days.It

maybe as short as 20 days or as long as 45

days in some women.



2 significant result of female sexual cycle

1.) only a single ovum is normally released from

the ovaries each month, so normally only a

single fetus will begin to grow at a time.

2.) the uterine endometrium is prepared in

advance for implantation of the fertilized

ovum at the required time of the month.



Gonadotropic Hormones and Their

Effects on the Ovaries

FSH and LH

-secreted by the anterior pituitary gland,in the

absence of these hormones, the ovariesremain inactive

-during puberty, the pituitary begins to

secrete FSH and LH, which leads to onset of

normal monthly sexual cycle.



Refer to figure 81-3 in the book.

During each month of the female sexual cycle,there

is a cyclical increase and decrease of both FSH

and LH.

Both FSH and LH stimulate their ovarian target cells

by combining with highly specific FSH and LH

receptors in the ovarian target cell membranes.In

turn, the activated receptors increase the cellsrates of secretion and usually the growth and

proliferation of cells as well.



Ovulation

-in a woman who has a normal 28 day female sexual cycle occurs 14 days after the

onset of menstruation.Initiation of Ovulation

Luteinizing Hormone

Follicular steroid hormones (progesterone)

Proteolytic enzymes follicular hyperemia and

( collagenase) prostaglandin secretion

Weakened follicle wall plasma transudation into follicle

Degeneration of stigma follicle swelling

follicle rupture

evagination of ovum



After ovulation, the secretory cells of the

ovulating follicle develop into corpus luteum

that secretes large quantities of both the

female hormones,progesterone and

estrogens.After 2 weeks, the corpus luteum

degenerates,where upon the hormone

progesterone and estrogen decreases greatlyand menstruation begins and a new ovarian

cycle then follows.



Functions of ovarian hormone-

estradiol and progesterone

2 types of ovarian sex hormones:

a.) estrogens

-the most important estrogens is the homoneestradiol

b.) progestins

-by far most important progestin is progesterone



Estrogens

In normal non-pregnant female

-estrogens are secreted in significant

quantities only by the ovaries,and minuteamounts are secreted by the adrenal cortex

During pregnancy

-

tremendous amounts are also secreted bythe placenta



3 Estrogens present in plasma og

human female:

1.) -estradiol-the principal estrogen secreted bythe ovaries; considered the major estrogen

2.) estrone-also secreted by the ovaries in small

amounts,but mostly they are formed in theperipheral tissues from androgens secreted bythe adrenal cortices and ovarian thecal cells.

3.) estriol-is a weak estrogen, it is an oxidativeproduct derived from both estradiol andestrone



Progestins

Progesterone- the most important of the

progetins

17 -hydroxyprogesterone

-another progestinspresent in small amounts



Functions of Estrogens-Their effects on primary and

secondary female sex characteristics

A primary function of of the estrogens is to cause cellularproliferation and growth of the tissues of the sexorgans and other tissues related to reproduction.

Effects of estrogens:

1.) on the uterus and external female sex organs

- at puberty, the female sex organs change from child

to an adult.the ovaries, fallopian tubes,uterus andvagina increases in size.and also the external genitaliaenlarge,with deposition of fats in mons pubis and labiamajora and enlargement of labia minora.



-the estrogens change the vaginal lining

epithelium from cuboidal into stratified type.

2.) fallopian Tube

- estrogens effect on the epithelial lining of

the uterine tubes,they cause the glandulartissues of this lining to proliferate,and most

importanly they cause the number of ciliated

epithelial cells that line the uterine tubes to

increased.



3.) on the breast

-they cause development of the stromal tissues

of the breasts,growth of an extensive ductile

system and deposition of fat in the breast.

-estrogens initiate growth of the breast and of

the milk producing apparatus,they also

responsible for the characteristic growth andexternal appearance of the mature female breast.



3.) on the skeleton

-estrogens inhibit osteaoclastic activity in the bones andtherefore stimulate bone growth.

-they cause uniting of the epiphyses with the shaft of the

long bones4.) on body metabolism and fat deposition

-estrogens increase the whole body metabolism rateslightly, they also cause deposition of increased quantitiesof fats in the subcutaneous tissues.as a result the

percentage of body fats in females is greater than in malebody

-also estrogens cause deposition of fat in the buttocks andthighs, which is characteristic of the feminine figure.



5.) on the skin

-estrogens cause the skin to develop a texturethat is soft and usually smooth.

-cause the skin to become more vascular;thisoften associated with increased warmth of theskin and also promotes greater bleeding of cutsurfaces than is observed in men.

6.) on electrolyte balance-estrogens like aldosterone and someadrenocorticotropic hormone cause sodium andwater retention by the kidney tubules.



Functions of Progesterone

Effect of Progesterone on the uterus

-function of progesterone is to promote secretorychanges in th uterine endometrium during the

latter half of the monthly female sexual cycle.On the fallopian tubes

-promotes increased secretion by the mucosallining of the uterine tubes.these secretions arenecessary for the nutrition of the fertilized,dividing ovum as it traverses the tube beforetransplantation.



On the breast

-promotes development of lobules and alveoli

of the breasts, causing the alveolar cells toproliferate, enlarge and become secretory in

nature.However it does not cause the alveoli

to secrete milk.

-it also causes breast to swell.

before pregnancy

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