External Structures
A. Visible Organs of the Vulva
Mons pubis—covered with pubic hair—located over pubic bones, serves a
protective function
Labia major and labia minora—two pairs of tissue surrounding the outer
part of the vulva.
Vestibule—surrounded by the labia it contains the vaginal opening and
urethra.
Vaginal opening
Clitoris—erectile tissue analagous to the penis
Urethral orifice
Perineum—the region of the genital area between the vulva and the anus.
This is the location of an episiotomy if performed during birth.
B. Breasts—mammary glands
Function is to secrete milk for infant—lactation.
After delivery, the withdrawal of estrogen and progesterone due to the
expulsion of the placenta cause prolactin to be produced, which stimulates
milk formation. Oxytocin is a hormone that stimulates the release of milk.
Internal Reproductive Organs
A. Located in the Pelvic Cavity
Ovaries—female gonads located on each side of the uterus. Functions
include
(1) Development and release of the ovum (egg)
(2) Secretion of the hormones estrogen and progesterone
Fallopian tubes
(1) Carry the ovum from the ovary to the uterus.
(2) Fimbriae sweep ovum into the tube.
Uterus
(1) Hollow pear-shaped organ that stretches and enlarges during
pregnancy to support the fetus.
(2) Other functions include menstruation and expelling of the fetus
during labor.
(3) Divisions of the uterus are: fundus—uppermost portion; corpus—the
body; cervix—lower third that exits into the vagina through the
cervical os.
Vagina
(1) Curved tube leading from the uterus to the vestibule.
(2) Functions as a passageway for menstrual flow, organ of copulation,
and birth canal.
Pelvis
A. Bones—support and protect pelvic contents
Sacrum—wedge-shaped bone formed by the fusion of five vertebrae
Coccyx—small triangular bone at bottom of the vertebral column.
Innominate bones
(1) Ilium—upper prominence of the hip
(2) Ischium—L-shaped bone below the ischium. Distance between the
ischial spines is the shortest diameter of the pelvic cavity.
(3) Pubis—slightly bowed front portion of the innominate bone. The
pubis meet at the front of the pelvis to make up the joint called the
symphysis pubis. Below the symphysis is a triangular space called
the pubic arch, under which the fetal head passes during birth.
B. Pelvic floor—muscular floor of bony pelvis, supports pelvic contents
Levator ani—major portion, made up of four muscles
(1) Ileococcygeus
(2) Puboccygeus
(3) Puborectalis
(4) Pubovaginalis
Coccygeal muscle—underlies sacrospinous ligament a thin muscular
sheet which helps the levator ani support the pelvic contents
C. Pelvic shapes—vaginal birth is never ruled out because of pelvic type
without a trial of labor.
Android—narrow, heart shaped, similar to shape of male pelvis—not
favorable for vaginal birth
Anthropoid—widest from front to back—usually adequate for vaginal
birth
Platypelloid—widest from side to side—not favorable for vaginal birth
Gynecoid—“classic” female pelvis—approximately 50 percent of
women and it’s the best for vaginal birth
Functions of the Female Reproductive System
1.External Genitalia
•The mons pubic protects the pubic bone from trauma.
•The clitoris provides for sexual arousal and orgasm.
•The labia majora and minora protect the external genitalia, urethra, and distal
vagina.
•Secretions from Bartholin’s glands lubricate the external vulva during coitus and
improve sperm survival.
•Secretions from Skene’s glands lubricate the external genitalia during coitus.
•The urethral meatus is the external opening of the female urethra.
•The perineal muscle expands during childbirth to enlarge the vagina, allowing for
passage of the fetal head.
2.Internal genitalia
•The vagina aids in conception by conveying sperm to the cervix and helps in
childbirth by serving as a passageway for the fetus.
•The uterus receives the fertilized egg, provides for implantation, nourishes and
protects the growing fetus, and contacts to expel the fetus during childbirth.
•The ovaries produce and release mature ova and regulate the menstrual cycle
through the production of estrogen and progesterone.
•The fallopian tubes move the sperm toward the ova and the ova toward the
uterus, thereby aiding in fertilization.
3.The pelvis supports and protects the reproductive and other pelvic organs.
During the late months of pregnancy, the false pelvis supports the uterus and
helps direct the fetus into the true pelvis for birth.
4.The breasts serve to produce and secrete (Lactate) milk for the infant.
Physiologic process of the female reproductive cycle
1.Menstruation Cycle
2.Gestation and lactation
•Fertilization of the ovum by a sperm usually occurs in the distal third of the
fallopian tube. About 5 days later, the zygote implants into the uterine
endometrium.
•Human chorionic gonadotropin, secreted by chronic villi in the endometrium of a
pregnant female, stimulates the corpus luteum to secrete estrogen and
progesterone until the placenta takes over.
•From the third to the eight week of gestation, all essential structures of the fetus
form. During the remaining weeks these existing structures grow and mature.
Throughout pregnancy, the placenta continues to produce progesterone and
estrogen. These hormones stimulate growth of the fetus and uterine blood supply,
affect contractile activity, stimulate growth of mammary tissue, and affect the
woman’s metabolism. Normally, around the 40th week of gestation, the fetus and
placenta are expelled from the body. Estrogen and progesterone play a role in
initiating parturition. Under the influence of oxytocin, regular contractions increase
in frequency and intensity to aid in this process of childbirth.
•The breast produce and release milk for the nourishment of the neonate. The
production and release of milk is influenced by prolactin, oxytocin and suckling of
the neonate. This process is referred to as lactation.
3.Menopause occurs when menses cease (for at least 1 year), in most women
between ages 40 and 55. After menopause, the ovaries atrophy, estrogen levels
fall, and changes occur in the vagina, cardiovascular system, skeletal system and
integumentary system.
