Prenancy & Ana Physio

ANATOMY AND PHYSIOLOGY OF THE REPRODUCTIVE SYSTEM

EXTERNAL GENITALIA

Our overview of the reproductive system begins at the external genital area— or vulva—which runs from the pubic area downward to the rectum. Two folds of fatty, fleshy tissue surround the entrance to the vagina and the urinary opening: the labia majora, or outer folds, and the labia minora, or inner folds, located under the labia majora. The clitoris,

is a relatively short organ (less than one inch long), shielded by a hood of flesh. When stimulated sexually, the clitoris can become erect like a man's penis. The hymen, a thin membrane protecting the entrance of the vagina, stretches when you insert a tampon or have intercourse.

INTERNAL REPRODUCTIVE STRUCTURE

The Vagina The vagina is a muscular, ridged sheath connecting the external genitals to the uterus, where the embryo grows into a fetus during pregnancy. In the reproductive process, the vagina functions as a two-way

street, accepting the penis and sperm during intercourse and roughly nine months later, serving as the avenue of birth through which the new baby enters the world . The Cervix The vagina ends at the cervix, the lower portion or neck of the uterus. Like the vagina, the cervix has dual reproductive functions. After intercourse, sperm ejaculated in the vagina pass through the cervix, then proceed through the uterus to the fallopian tubes where, if a sperm encounters an ovum (egg), conception occurs. The cervix is lined with mucus, the quality and quantity of which is governed by monthly fluctuations in the levels of the two principle sex hormones, estrogen and progesterone. When estrogen levels are low, the mucus tends to be thick and sparse, which makes it difficult for sperm to reach the fallopian tubes. But when an egg is ready for fertilization and estrogen levels are high the mucus then becomes thin and slippery, offering a much more friendly environment to sperm as they struggle towards their goal. (This phenomenon is employed by birth control pills, shots and implants. One of the ways they prevent conception is to render the cervical mucus thick, sparse, and hostile to sperm.)

Uterus The uterus or womb is the major female reproductive organ of humans. One end, the cervix, opens into the vagina; the other is connected on both sides to the fallopian tubes. The uterus mostly consists of muscle, known as myometrium. Its major function is to accept a fertilized ovum which becomes implanted into the endometrium, and derives nourishment from blood vessels which develop exclusively for this purpose. The fertilized ovum becomes an embryo, develops into a fetus and gestates until childbirth. Oviducts The Fallopian tubes or oviducts are two very fine tubes leading from the ovaries of female mammals into the uterus. On maturity of an ovum, the follicle and the ovary's wall rupture, allowing the ovum to escape and enter the Fallopian tube. There it travels toward the uterus, pushed along by movements of cilia on the inner lining of the tubes. This trip takes hours or days. If the ovum is fertilized while in the Fallopian tube, then it normally implants in the endometrium when it reaches the uterus, which signals the beginning of pregnancy. Ovaries The ovaries are the place inside the female body where ova or eggs are produced. The process by which the ovum is released is called

ovulation. The speed of ovulation is periodic and impacts directly to the length of a menstrual cycle. After ovulation, the ovum is captured by the oviduct, where it travelled down the oviduct to the uterus, occasionally being fertilised on its way by an incoming sperm, leading to pregnancy and the eventual birth of a new human being. The Fallopian tubes are often called the oviducts and they have small hairs (cilia) to help the egg cell travel.

Pregnancy

Pregnancy, the state of carrying a developing embryo or fetus within the female body. This condition can be indicated by positive results on an over-the-counter urine test, and confirmed through a blood test, ultrasound, detection of fetal heartbeat, or an X-ray. Pregnancy lasts for about nine months, measured from the date of the woman's last menstrual period (LMP). It is conventionally divided into three trimesters, each roughly three months long.

When gestation has completed, it goes through a process called delivery, where the developed fetus is expelled from the mother’s womb. There are two options of delivery: Cesarean section and NSVD or normal spontaneous vaginal delivery. A cesarean section is a surgical incision through the mother’s abdomen and uterus to deliver one or more fetuses. NSVD or normal spontaneous vaginal delivery is the delivery of the baby through vaginal route. It can also be called NSD or normal spontaneous delivery, or SVD or spontaneous vaginal delivery, where the mother delivers the baby with effort and force exertion.

Normal labor is defined as the gradual subjugation and dilatation of the uterine cervix as a result of rhythmic uterine contractions leading to the expulsion of the products of conception: the delivery of the fetus, membranes, umbilical cord, and placenta. Laboring cannot that be easy; thereby implicating that there are processes and stages to be undertaken to achieve spontaneous delivery. Through which, Obstetrics

have divided labor into four (4) stages thereby explaining this continuous process.

STAGE 1: It is usually the longest part of labor. It begins with regular uterine contractions and ends with complete cervical dilatation at 10 centimeters. This stage is broken down into three (3) phases: the Early phase, where the contractions are usually very light and maybe approximately 20 minutes or more apart from the beginning, gradually becoming closer, possibly up to five minutes apart; the Active phase, where contractions are generally four or five times apart, and may last up to 60 seconds long. Cervix dilates with 4-7 cm and initiates a more rapid dilatation. It is known that to get through active labor, mobility and relaxations are done to increase contractions; and the Transition phase, where it is definitely known as the shortest phase but the hardest, contractions maybe two or three times apart, lasting up to a minute and a half, about approximately 8-10 cm of cervical dilatation. Some women will shake and may vomit during this stage, and this is regarded as normal. Most of the time, women would find a comfortable position to acquire complete dilatation.

STAGE II: This stage lasts for three or more hours. However, the length of this stage depends upon the mother’s position (e.g.; upright position yields faster delivery). Once the cervix has completely dilated,

the second stage had begun. This stage ends with the expulsion of the fetus.

STAGE III: This stage focuses on the expulsion of the placenta from the mother. Placenta exclusion is much more easier than the delivery of the baby because it includes no bones, and this is during this stage that the baby is placed on top of the mother’s womb.

STAGE IV: No more expulsions of conception products for this stage as this is generally accepted as POST PARTUM juncture. This phase is from the placental delivery to full recovery of the mother.

Labor and delivery of the fetus entails physiological effects both on the mother and the fetus.

In the cardiovascular system, the

mother’s cardiac output increases because of the increase in the needed amount of blood in the uterine area. Blood pressure may also rise due to the effort exerted by the mother in order expel the fetus. There could also be a development of leukocytes or a sharp increase in the number of circulating white blood cells possibly as a result of stress and heavy exertion. Increased respiratory may also occur. This happens as a response to the increase in blood supply in order to increase also the oxygen intake. With delivery imminent, the mother is usually placed supine with her knees bent (ie, the dorsal lithotomy position). An episiotomy (an

incision continuous with the vaginal introitus) may be performed at this time. Episiotomy may ease delivery of the fetal head and allow some control over what may otherwise be an uncontrolled perineal laceration. However, many providers no longer perform routine episiotomy, since it may increase the risk of rectal injury and are larger than the spontaneous laceration.

The labor and birth process is always accompanied by pain. Several options for pain control are available, ranging from intramuscular or intravenous doses of narcotics, such as Meperidine (Demerol), to general anesthesia. Regional nerve blocks, such as a pudendal block or local infiltration of the perineal area can also be used. Further options include epidural blocks and spinal anesthetics.