Page 94 - 86 human physiology part-2

The Female Reproductive System

entrance to the vagina.
Mound of skin and underlying fatty
Mons
tissue, central in lower pelvic region
Provides an environment for maturation of
Ovaries (female Pelvic region on either side of the oocyte. Synthesizes and secretes sex hormones
gonads) uterus.
(estrogen and progesterone).
Short stretch of skin starting at the
Perineum bottom of the vulva and extending to
the anus.
Urethra Pelvic cavity above bladder, tilted. Passage of urine.
Uterus Center of pelvic cavity. To house and nourish developing human.
Receives penis during mating. Pathway
through a womans body for the baby to take
Canal about 10-8 cm long going during childbirth. Provides the route for the
Vagina from the cervix to the outside of the menstrual blood (menses) from the uterus, to
body. leave the body. May hold forms of birth
control, such as an IUD, diaphragm, neva ring,
or female condom
Surround entrance to the
Vulva reproductive tract.(encompasses all
external genitalia)
Contains glands that secrete fluids that bathe
Endometrium The innermost layer of uterine wall.
the utrine lining.
Myometrium Smooth muscle in uterine wall. Contracts to help expel the baby.

The Female Reproductive Cycle

Towards the end of puberty, girls begin to release eggs as part of a monthly period called the
female reproductive cycle, or menstrual cycle (menstrual referring to "monthly"). Approximately
every 28 days, during ovulation, an ovary sends a tiny egg into one of the fallopian tubes. Unless the
egg is fertilized by a sperm while in the fallopian in the two to three days following ovulation, the egg
dries up and leaves the body about two weeks later through the vagina. This process is called
menstruation. Blood and tissues from the inner lining of the uterus (the endometrium) combine to form
the menstrual flow, which generally lasts from four to seven days. The first period is called menarche.
During menstruation arteries that supply the lining of the uterus constrict and capillaries weaken. Blood
spilling from the damaged vessels detaches layers of the lining, not all at once but in random patches.
Endometrium mucus and blood descending from the uterus, through the liquid creates the menstruation
flow.

The reproductive cycle can be divided into an ovarian cycle and a uterine cycle (compare ovarian
histology and uterine histology in the diagram on the right). During the uterine cycle, the endometrial
lining of the uterus builds up under the influence of increasing levels of estrogen (labeled as estradiol in
the image). Follicles develop, and within a few days one matures into an ovum, or egg. The ovary then
releases this egg, at the time of ovulation. After ovulation the uterine lining enters a secretory phase, or
the ovarian cycle, in preparation for implantation, under the influence of progesterone. Progesterone is
produced by the corpus luteum (the follicle after ovulation) and enriches the uterus with a thick lining
of blood vessels and capillaries so that it can sustain the growing fetus. If fertilization and implantation

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