Anatomy & Physiology Of Female Reproductive System

ANATOMY & PHYSIOLOGY OF FEMALE REPRODUCTIVE SYSTEM

 EXTERNAL STUCTURES

a. Mons Veneris •

A pad of adipose tissue located over the symphisis pubis, the pubic bone joint.

•

It protects the junction of pelvic bone from trauma.

b. Labia Minora •

Just posterior to the mons veneris spread two hairless folds of connective tissue.

c. Labia Majora •

Two halves of adipose tissue covered by loose connective tissue and epithelium.

d. Vestibule •

Flattened smooth surface inside the labia.

•

The space wherein we can see the vaginal and uretral opening.

e. Clitoris •

Small rounded erectile tissue at the forward junction of the labia minora.

•

Sensitive to touch and temperature center of sexual arousal and orgasm.

f. Skene’s Gland

PARAURETRAL GLANDS •

Located just lateral to urinary meatus.

•

It produces lubricating fluid that helps to maintain the moistness of the vestibule.

Bartholin’s Gland (vulvovaginal) •

Located just lateral to vaginal opening.

•

It secretes mucus to provide vaginal lubrications.

g. Fourchette •

Ridge of tissues formed by the posterior joining the two labias.

 INTERNAL STRUCTURES

1. Ovaries • Almond shaped • Produce, mature and discharge ova • Initiate and regulate menstrual cycle • 4 cm long, 2 cm in diameter, 1.5 cm thick • Produce estrogen and progesterone -

Estrogen: promotes breast development & pubic hair distribution prevents osteoporosis and keeps cholesterol levels reduced & so limits effects of atherosclerosis Fallopian tubes.

2. Fallopian tubes • Approximately 10 cm in length • Arises from each corner of the uterine body • Conveys ova from ovaries to the uterus • Site of fertilization • Parts: interstitial isthmus – cut/sealed in BTL ampulla – site of fertilization infundibulum – most distal segment; covered with fimbria 3.

Uterus • Hollow muscular pear shaped organ - uterine wall layers: endometrium(inner); myometrium(middle); perimetrium(outer) • Organ of menstruation • Receives the ova • Provide place for implantation & nourishment during fetal growth • Protects growing fetus • Expels fetus at maturity • Has 3 divisions: corpus – fundus , isthmus (most commonly cut during CS delivery) and cervix.

4.

Uterine Wall • Endometrial layer: formed by 2 layers of cells which are as follows: • basal layer- closest to the uterine wall. • glandular layer – inner layer influenced by estrogen and progesterone; thickens and shed off as menstrual flow. • Myometrium – composed of 3 interwoven layers of smooth muscle; fibers are arranged in longitudinal; transverse and oblique directions giving it extreme strength.

5. Vagina • Acts as organ of copulation • Conveys sperm to the cervix • Expands to serve as birth canal • Wall contains many folds or rugae making it very elastic Fornices – uterine end of the vagina; serve as a place for pooling of semen following coitus. • Bulbocavernosus – circular muscle act as a voluntary sphincter at the external opening to the vagina (target of Kegel’s exercise).

 Menstrual Cycle

1. in 2. and 3.

Its

 Menstrual

Female reproductive cycle wherein periodic uterine bleeding occurs response to cyclic hormonal changes. Allows for conception implantation of a new life. purpose it to bring an ovum to maturity; renew a uterine bed that will be responsive to the growth of a fertilized ovum. Phases

•

•

•

•

First (proliferative): 4-5 days after the menstrual flow; the endometrium is very thin, but begins to proliferate rapidly; thickness increase by 8 folds under the influence of increase in estrogen level. Secondary (secretory): after ovulation the corpus luteum produces progesterone which causes the endometrium become twisted in appearance and dilated; capillaries increase in amount (becomes rich, velvety and spongy in appearance also known as: secretory; progestational; luteal and premenstrual. Third (ischemic): if no fertilization occurs; corpus luteum regresses after 8 – 10 days causing decrease in progesterone and estrogen level leading to endometrial degeneration; capillaries rupture; endometrium sloughs off ; also known as: ischemic. Final phase: end of the menstrual cycle; the first day mark the beginning of a new cycle; discharges contains blood from ruptured capillaries, mucin from glands, fragments of endometrial tissue and atrophied ovum.

 Characteristics of Normal Menstruation Period 1. 2. 3. 4. 5. 6.

Menarche – average onset 12 -13 years Interval between cycles – average 28 days Cycles 23 – 35 days Duration – average 2 – 7 days; range 1 – 9 days Amount – average 30 – 80 ml ; heavy bleeding saturates pad in <1hour Color – dark red; with blood; mucus; and endometrial cells

 Associated Terms 1. 2. 3. 4. 5.

Amenorrhea - temporary cessation of menstrual flow Oligomenorrhea - markedly diminished menstrual flow Menorrhagia - excessive bleeding during regular menstruation Metrorrhagia - bleeding at completely irregular intervals Polymenorrhea - frequent menstruation occurring at intervals of less than 3 weeks

 Ovulation 1. Occurs approximately the 14th day before the onset of next cycle (2 weeks before) 2. If cycle is 20 days – 14 days before the next cycle is the 6th day, so ovulation is day 6 3. If cycle is 44 days – 14 days, ovulation is day 30.

4. Slight drop in BT (0.5 – 1.0 °F) just before day of ovulation due to low progesterone level then rises 1°F on the day following ovulation (spinnbarkheit; mittelschmerz) 5. If fertilization occurs, ovum proceeds down the fallopian tube and implants on the endometrium.  Menopause • • • •

Mechanism- a transitional phase (period of 1 – 2 years) called climacteric, heralds the onset of menopause. Monthly menstrual period is less frequent, irregular and with diminished amount. Period may be ovulatory or unovulatory - advised to use Family planning method until menses have been absent for 6 continuous months Menopause is has occurred if there had been no period for one year.

 PLACENTA •

It serve s as the fetal lungs, kidneys and gastrointestinal tract and as a separate endocrine organ throughout pregnancy.

 CIRCULATION •

The fetus is connected by the umbilical cord to the placenta, the organ that develops and implants in the mother's uterus during pregnancy.

•

As early as the 12th day of pregnancy, maternal blood circulation begins to collect in the intervillus spaces of the uterine endometrium surrounding the chronic villi. By the 3rd week of pregnancy, through the blood vessels in the umbilical cord, the fetus receives all the necessary nutrition, oxygen, and life support from the mother through the placenta.. From there, the nutrients are being transported back to the growing embryo.

•

• • •

Waste products and carbon dioxide from the fetus are sent back through the umbilical cord and placenta to the mother's circulation to be eliminated. The blood from the mother enters the fetus through the vein in the umbilical cord. It goes to the liver and splits into three branches. The blood then reaches the inferior vena cava, a major vein connected to the heart.



•

Inside the fetal heart - Blood enters the right atrium, the chamber on the upper right side of the heart. Most of the blood flows to the left side through a special fetal opening between the left and right atria, called the foramen ovale. - Blood then passes into the left ventricle (lower chamber of the heart) and then to the aorta, (the large artery coming from the heart). - From the aorta, blood is sent to the head and upper extremities. After circulating there, the blood returns to the right atrium of the heart through the superior vena cava. - About one-third of the blood entering the right atrium does not flow through the foramen ovale, but, instead, stays in the right side of the heart, eventually flowing into the pulmonary artery.

Because the placenta does the work of exchanging oxygen (O2) and carbon dioxide (CO2) through the mother's circulation, the fetal lungs are not used for breathing. Instead of blood flowing to the lungs to pick up oxygen and then flowing to the rest of the body, the fetal circulation shunts (bypasses) most of the blood away from the lungs. In the fetus, blood is shunted from the pulmonary artery to the aorta through a connecting blood vessel called the ductus arteriosus.