6.1 Female Reproductive System

Portage Learning BIOD 152

The female reproductive system includes

the ovaries, oviducts (fallopian or uterine tubes), uterus, vagina and vulva

Two functions of the female reproductive system

produce eggs and estogen

maintain the developemnt of a fetus after fertilization of an egg occurs

the main reproductive organ in females

• are two glands that are almond shaped

  • one on each side of the uterus

ovaries

inside each ovary

• hold an immature egg

ovarian follicles

the release of a mature egg, occurs every 28 days

ovulation

steps in the ovarian cycle

1. egg is released from the ovarian follcile

   1. the egg becomes the corpus luteum after ovulation

helps maintain pregnancy if an egg is fertilized; if not, it disintegrates

corpus luteum

included in the duct system

the oviducts, uterus and vaginal canal

also called uterine or fallopian tubes, extend from the ovaries to the uterus

oviducts

the three sections of a fallopian tube

infundibulium, ampulla and isthmus

three coats of the fallopian tube

the outer serous coat, middle muscular coat and inner mucosa coat

the finger-like projections of the oviducts that project onto the infundibulum end of the tube farthest from the uterus

fimbriae

when an egg bursts from the follicle within an ovary during ovulation, it is swept into a _ by the combined action of the _ and the beating of the _ that line the oviducts

oviduct, fimbriae, cilia

the region of the tube where the egg is often fertilized

ampulla

the ampulla region nourishes the fertilized egg during its early cell divisions

zygote

the _ layer of the ampulla provides nourishing fluid that allows repeated cell divisions

mucosa layer

over the next several days, the combination of muscular contractions and cilia move the egg through the _ towards the uterus

isthmus

this opens into the uterus, delivering the developing embryo into the uterine cavity when it is time for implantation

isthmus

a hollow, thick-walled muscular organ shaped like an inverted pear connecting the uterine tubes and vagina, and it is in a forward-tilted position between the bladder and rectum

uterus

the uterus has three layers

the outer serous perimetrium, middle muscular myometrium, inner glandular endometrium

the layer of the uterus that expands during pregnancy to hold the growing fetus and contracts during labor to push the baby out of the utuerus

muscular myometrium

where the embryo completes development

• is shed monthly if the female is not pregnant, also known as _

inner endometrium layer, menstruation

the upper part of the uterus, the height of which can be measured from the top of the pubic bone during pregnancy to provide growth rates and a crude indication of an abnormality (breech or twins)

fundus

the middle section of the uterus receives the fertilized ovum where it becomes implanted in the endometrium to receive nourishment and develop from ovum to embryo to fetus to gestate until childbirth

body

the lower portion of the uterus connects the uterus to the vagina and changes in size and texture

• just before ovulation, this swells, softens, and secretes mucus, allowing sperm better access to and viability within the uterus

cervix

whe a femal becomes pregnant, a _ develops in the cervix and prevents any bacteria or pathogens rfom entering the uterus, thus protecting the health of the developing fetus

mucous plug

a small opening at the cervix

• an elastic muscular tube that leads from the cervix of the uterus to the outside of the body

vaginal canal

the vaginal wall consists of

an inner tissue layer, intermediate muscle layer and outer tissue layer

the outer vaginal layer is made up of:

• the _ give the vaginal wall its strength and elasticity

  • the _ of the vagina lies in folds and can extend, which is important when the vagina serves as the birth canals and it also facilitates intercourse

inner tissue layer, intermediate muscle layer, outer tissue layer

• elastic fibers

• mucosal lining

external genitalia, consisting of the mons pubis, vestibule, labia majora, labia minora, clitoris, urethral and vaginal orifices

vulva

a fat pad located in front of the pubic symphysis and is covered with hair after puberty

mons pubis

surrounds the urethral and vaginal orifices

vestibule

an outer fold of skin that is located posterior to the mons pubis

labia majora

a second set of skin folds surrounded by the labia majora

labia minora

at the anterior end of the labia majora

clitoris

openings for the urethra and vagina are located inside the labia minora

orifices

made of female breast tissue, contains one to two dozen lobules, each with its own duct

mammary gland

begins at the nipple and divides into numerous other _ ending in blind sacs called alveoli (made up of cells that produce milk)

ducts

in non-lactating breats the _ out number the _

ducts, alveoli

milk is not produced during pregnancy because prolactin is needed for milk production

lactation

hormone responsible for milk production

prolactin

prolactin is suppressed by _ and _

estrogen and progesterone

prior to milk production, the breasts produce a watery, yellowish-white fluid, which has a similar composition to milk but contains a higher concentration of protein

colostrum

the production of eggs in the ovaries that occurs during the development of the fetus in the womb and is complete by the time of birth

• at birth, a female has all the immature eggs that she can later ovulate during her reproductive lifetime

• from puberty to about 50

oogenesis

the end of the female reproductive lifetime

menopause

female stem cells, known as _ undergo mitotic division into two daughter cells known as _

oogonia, primary oocytes

primary oocytes are covered by follicles known as _, this process is completed by birth

primary follicles

the anterior pituitary gland starts to secrete _ when a female reaches puberty

• causes a few follicales to mature each month

  • the primary oocyte in the follicle undergoes its first meiotic division into two daughter cells:

FSH

secondary oocyte and first polar body

this is produced so that the chromosomes divide properly, but all the cytoplasm is “donated” from the _ to the secondary oocyte in case of fertilization

polar body

if the secondary oocyte is united with a sperm after ovulation, the second meiotic division occurs, which produces a _ and an _ with 23 chromosomes

second polar body, ovum

the ovum and the sperm combine their chromosomes to form a fertilized egg with _ chromosomes

• the first polar body may or may not undergo a second meiotic division, therefore females produce two to three polar bodies and one viable gamete (ovum) with 23 chromosomes

  • if the secondary oocyte does not combine with a sperm, it dies, and menstruation occurs

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around the time of ovulation, the anterior pituitary secretes a second hormone called:

• causes the follicle to become the _, which is necessary for maintaining pregnancy

LH, corpus luteum

a hormone important in the production of eggs and the menstrual cycle

• is also responsible for _: including enlarged breasts, widening of the pelvis, and fat deposits in the breast, hips, and buttocks

estrogen, secondary sex characteristics

a hormone that is necessary for the maintenance of pregnancy but does not promote secondary sexual characteristics

progesterone

is closely integrated with the menstrual cycle

• every month, the ovaries release hormones that (estrogen and progesterone) that cause changes to the endometrium of the uterus, preparing for implantaiton if fertilization occurs

  • if fertilization does not occur, the endometrium is shed

the ovarian cycle

three phases of the menstrual cycle

the menstrual phase, proliferation phase, and secretory phase

this part of the menstrual cycle begins on day 1 when all but the innermost basal layer of the endometrium is shed and continues through day five

menstrual phase

the detached tissue of the endometrium and blood flow from the uterus into the vagina and exit the body via the vaginal orifice as the _

menstrual flow

this phase occurs during days 6-14 as the endometrium rebuilds in response to increasing estrogen levels

• ovulation of an egg typically occurs in the ovaries on day 14

proliferative phase

ovulation is triggered when the anterior pituitary releases

LH as a response to high levels of estrogen

the final phase which occurs during days 15-28

• during this phase the _ begins to secrete _

• this hormone causes an increased blood supply in the uterus and secretion of nutrients, preparing the uterus for implantation

  • if fertilization has not occurred, the corpus luteum dies and the endometrium blood supply decreases because of decreased progesterone, which begins the menstrual phase again

secretory phase

corpus luteum, progesterone