MED TERM Chapter 13 - Lecture notes Gynecology and Obstetrics PDF

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MEDICAL TERMINOLOGY: Chapter 13Gynecology and ObstetricsObjectives of Chapter 13: Identify structures of the female genital and reproductive system. Describe the processes of oogenesis, menstruation, conception, labor, and delivery. Describe normal and abnormal findings in the neonate. Describe comm...

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MEDICAL TERMINOLOGY: Chapter 13 Gynecology and Obstetrics

Objectives of Chapter 13: 1. 2. 3. 4. 5. 6. 7. 8. 9. 10.

Identify structures of the female genital and reproductive system. Describe the processes of oogenesis, menstruation, conception, labor, and delivery. Describe normal and abnormal findings in the neonate. Describe common female genital and reproductive, and common neonatal, diseases, laboratory and diagnostic procedures, medical and surgical procedures, and drugs. Form the plural and adjective forms of nouns related to gynecology, obstetrics, and neonatology. Give the meanings of word parts and abbreviations related to gynecology, obstetrics, and neonatology. Divide gynecology, obstetrics, and neonatology words and build these words. Spell and pronounce gynecology, obstetrics, and neonatology words. Research sound-alike gynecology and other words. Analyze the medical content and meaning of gynecology and neonatal reports.

Anatomy and Physiology The female genital and reproductive system includes both internal and external genitalia or genital organs. The internal genitalia in the pelvic cavity include the ovaries, uterine tubes, uterus, and vagina. The external genitalia include the area of the mons pubis, labia majora, labia minora, clitoris, and vaginal introitus. The breasts or mammary glands also play a role in the female reproductive system. The female genital and reproductive system together with the urinary system is known as the genitourinary (GU) system or urogenital system because of the close proximity of these two body systems. The function of the female genital and reproductive system is to secrete the female hormones, develop the female secondary sexual characteristics, produce ova (eggs), menstruate, conceive and bear children, and produce milk to nourish children.

Anatomy of the Female Genital and Reproductive System Ovaries An ovary is a small egg-shaped gland about 2 inches in length near the end of a uterine tube. The ovaries are held in place by the broad ligament, a folded sheet of peritoneum that extends to the walls of the pelvic cavity, and by other ligaments. The ovaries are the gonads or sex glands in a female. They function as part of the female genital and reproductive system and the endocrine system. The ovaries contain follicles that rupture, releasing ova (eggs) during the menstrual cycle. The ovaries are glands that secrete three hormones (estradiol, progesterone, and testosterone), and these hormones affect puberty, menstruation, and pregnancy.

Uterine Tubes Each uterine tube is about 5 inches in length and is held in place by the broad ligament. The function of the uterine tube is to transport an ovum from the ovary to the uterus. The medial end of the uterine tube is connected to the uterus, but its lateral end is not connected to the ovary. There is an open space (part of the abdominopelvic cavity) between each ovary and its uterine tube. The ovary releases an ovum into this open space. Fimbriae, moving, fingerlike projections at the end of the uterine tube, create currents that carry the ovum into the lumen of the tube. Within the uterine tube, cilia (tiny hairs) beat in waves while peristalsis (coordinated, wavelike contractions of smooth muscle around the tube) propels the ovum toward the uterus. Fluid inside the uterine tube contains nutrients to nourish the ovum on its 3-day journey to the uterus. The uterine tube is also known as the oviduct. Together, the ovaries and the uterine tubes are known as the adnexa.

Uterus The uterus is an inverted pear-shaped organ about 3 inches in length. The uterus is held in place by the broad ligament and other ligaments that go from the uterus to the sides of the pelvic walls and to the bony sacrum. The broad ligament creates a small pouch, the cul-de-sac, between the uterus and the rectum (see Figure 13-2). The fundus is the rounded top of the uterus. The body of the uterus is its widest part. The body narrows and becomes the cervix (neck of the uterus). Within the uterus is the hollow intrauterine cavity, which narrows into the cervical canal . The cervical os in the center of the cervix is the opening of the cervical canal. The rounded tip of the cervix projects about ½ inch into the vagina. The superior portion of the uterus is tipped anteriorly, and part of it rests on the urinary bladder (see Figure 13-2); this normal position is known as anteflexion.

The wall of the uterus is composed of three layers: perimetrium, myometrium, and endometrium. The perimetrium is the outer layer. It is a serous membrane that is part of the peritoneum that lines the abdominopelvic cavity. The myometrium or uterine muscle contains smooth muscle fibers that are oriented in different directions. This allows the uterus to contract strongly from all sides during labor and the delivery of a baby. The innermost layer, the endometrium, lines the intrauterine cavity. It is a mucous membrane that contains glands, and this layer thickens during the menstrual cycle. If an ovum is not fertilized, this lining is shed during menstruation. Vagina The vagina is a short, tubelike structure about 3 inches in length. Within the vagina is the open vaginal canal. The cervix of the uterus protrudes into the superior end of the vaginal canal. The fornix is the area of the vaginal canal that is behind and around the cervix. At the inferior end of the vaginal canal is the hymen , an elastic membrane that partially or completely covers the opening, although it is sometimes absent. The hymen, if present, is easily torn by the insertion of a tampon, a vaginal examination, or sexual intercourse. The vagina has three functions. During menstruation, it transports the shed endometrium to the outside of the body. During sexual intercourse, it holds the penis and collects the ejaculate that contains spermatozoa. During birth, it is part of the birth canal that takes the baby to the outside of the mother’s body.

External Genitalia

The external genitalia include the mons pubis, labia majora, labia minora, clitoris, vaginal introitus, and glands that produce lubricating secretions. The mons pubis is the rounded, fleshy pad with pubic hair that overlies the pubic bone. The labia consist of two sets of lip-shaped structures that run anteriorly to posteriorly and partially cover the urethral meatus and vaginal introitus. The thicker, outermost lips, the labia majora , are fleshy and covered with pubic hair on their outer surface. The smooth, thin, inner lips, the labia minora, lie beneath the labia majora. The clitoris is the organ of sexual response in the female. Its tip is located anterior to the urethral meatus. With sexual stimulation, the clitoris enlarges with blood and becomes firm. The vaginal introitus is the opening to the outside of the body; it is posterior to the urethral meatus. Three sets of glands near the vaginal introitus—Bartholin’s glands, the urethral glands, and Skene’s glands (BUS)—secrete mucus during sexual arousal. The vulva includes all of these structures. The area between the vulva and the anus is the perineum .

Breasts The breasts or mammary glands are located on the chest. They contain adipose (fatty) tissue and glands. The breasts develop at puberty in response to estradiol secreted by the ovaries. They are one of the female sexual characteristics, and they also provide milk to nourish the newborn after birth. The breasts contain lactiferous lobules that produce milk. Milk flows through the lactiferous ducts to the nipple. The areola is the pigmented area around the nipple. The surface of the areola is covered with small, elevated areas that secrete oil to protect the nipple when the baby nurses.

Physiology of Sexual Maturity, Oogenesis, Menstruation, and Conception Sexual Maturity and Oogenesis At the onset of puberty (adolescence), the anterior pituitary gland in the brain begins to secrete two hormones that stimulate the ovaries. 1. Follicle-stimulating hormone (FSH). FSH stimulates a follicle in the ovary to enlarge and produce a mature ovum. Oogenesis is the process of forming a mature ovum. Like a spermatozoon, the mature ovum is created by mitosis and meiosis. Like a spermatozoon, the mature ovum is known as a gamete. However, unlike spermatozoa, only a single ovum is produced. It contains 23 chromosomes, and the remaining chromosomes are discarded in small packets of cytoplasm known as polar bodies. FSH also stimulates the follicles to secrete estradiol, which causes the development of the female sexual characteristics during puberty. 2. Luteinizing hormone (LH). LH stimulates a single follicle each month to rupture and release its mature ovum. Then it stimulates the ruptured follicle (corpus luteum) to secrete estradiol and progesterone. The ovary secretes these three hormones: 1. Estradiol. The most abundant and most biologically active of the female hormones. It is secreted by each follicle (and also by the ruptured follicle [corpus luteum] after ovulation). Estradiol causes the development of these female sexual characteristics during puberty: enlargement of the external genitalia, development of the breasts,

widening of the pelvis, growth of body hair in the axillary and genital areas, and development of the sexual drive. Estradiol also causes the endometrium (lining of the uterus) to thicken during the menstrual cycle. Estradiol is also secreted by the placenta during pregnancy. 2. Progesterone. Hormone secreted by a ruptured follicle (corpus luteum) after ovulation. Progesterone also causes the endometrium to thicken during the menstrual cycle. It is also secreted by the placenta during pregnancy. 3. Testosterone. A male hormone secreted by cells around the follicle. It plays a role in the female sexual drive.

The Menstrual Cycle With the onset of puberty, the female begins to ovulate and menstruate. Menarche is the beginning of menstruation, which occurs with the first menstrual period or menses. Each menstrual cycle, on average, lasts 28 days and includes four phases: the menstrual phase, the proliferative phase (followed by ovulation), the secretory phase, and the ischemic phase. 1. Menstrual phase (Days 1–6) Menstruation begins. Approximately 30 mL of blood, endometrial tissue, and mucus is sloughed off from the uterus and passes through the vagina. All that remains of the endometrium is a thin layer of glands. At the same time, several follicles in the

ovary are enlarging and their ova are maturing in preparation for one of them to be released during ovulation on day 14. 2. Proliferative phase (Days 7–13) Follicle-stimulating hormone (FSH) from the anterior pituitary gland stimulates the ovarian follicles to secrete estradiol. One follicle becomes greatly enlarged and produces a mature ovum. The endometrium in the uterus becomes thicker because of estradiol. At the end of the proliferative phase, mucus in the cervical canal thins to allow spermatozoa to pass through it. a. Ovulation (Day 14) Luteinizing hormone (LH) from the anterior pituitary gland causes the enlarged ovarian follicle to rupture, releasing a mature ovum. The basal (baseline) body temperature rises about 0.4 degrees at the time of ovulation and stays elevated until the onset of menstruation 3. Secretory phase (Days 15–26) The ruptured ovarian follicle fills with yellow fat and becomes the corpus luteum. The corpus luteum secretes estradiol and progesterone. Progesterone causes the endometrial glands of the uterus to enlarge, and the endometrium becomes thicker. Small arteries grow to the innermost edge of the endometrium, ready to nourish a fertilized ovum, if one enters the uterus. The basal body temperature continues to be elevated due to progesterone. 4. Ischemic phase (Days 27–28) The corpus luteum turns into white scar tissue (corpus albicans) and stops secreting estradiol and progesterone. The abrupt decrease in these hormones causes the small arteries in the endometrium to contract. This stops the flow of blood and causes ischemia of the tissue. The endometrium begins to slough off, and menstruation (the first phase of the menstrual cycle) begins again.

Conception Of the 100–500 million spermatozoa deposited in the vagina during sexual intercourse, only some are able to reach the ovum in the uterine tube; this occurs 24–48 hours after sexual intercourse. Chemicals secreted by the ovum attract the spermatozoa. A caplike layer of enzymes on the head of each spermatozoon begins to dissolve the layer of cells around the ovum. Many spermatozoa attach to the ovum, but only one penetrates its surface. This is the moment of fertilization or conception . After that, the surface of the ovum changes and actually repels the other spermatozoa. When a spermatozoon unites with an ovum, the resulting cell has 46 chromosomes and is known as a zygote. Pregnancy begins at the moment of conception. A zygote immediately begins to divide as it moves through the uterine tube. Within the intrauterine cavity, it sinks into the thickened endometrium. At this point, the zygote is a hollow ball with an inner mass of cells and an outer layer. The inner mass of cells becomes the amnion and the embryo. The amnion (or bag of waters) is a membrane sac that produces amniotic fluid. The developing embryo floats in, and is cushioned by, the amniotic fluid. The outer layer of the zygote becomes the chorion . It sends fingerlike projections (villi) into the endometrium to absorb nutrients and oxygen. The chorion produces the hormone human chorionic gonadotropin (HCG). HCG stimulates the corpus luteum of the ovary to keep producing estradiol and

progesterone. This maintains the thickened endometrium to support the developing embryo and prevents menstruation from occurring during the rest of the pregnancy. The chorion becomes the placenta, a pancake-like structure about 7 inches in diameter and 1–2 inches thick. By the end of the first trimester of pregnancy, the placenta begins to secrete estradiol and progesterone and takes over the job of the corpus luteum in the ovary. Other structures in the chorion form the rubbery, flexible umbilical cord (with its two arteries and one vein) that connects the placenta to the fetus. The umbilical cord and placenta bring oxygen, nutrients, and antibodies from the mother to the fetus and remove carbon dioxide and waste products. After 4 days of development, the zygote is known as an embryo. After 8 weeks, it is known as a fetus. The fetus, placenta, and all fluids and tissue in the uterus are known as the products of conception . Gestation is from the moment of conception to the moment of birth. The gestational period is approximately 9 months (38–42 weeks), the average being 40 weeks. Gestation can be divided into three time periods, or trimesters . Each trimester is 3 months long. For the fetus, the period of time from conception to birth is the prenatal period. For the mother, the period of time from conception to birth is known as antepartum.

Physiology of Labor and Delivery As the fetus grows, the uterus expands, taking up space in the mother’s abdominal cavity and displacing her abdominal organs. This causes constipation, urinary frequency, and shortness of breath in the mother. During the last trimester of pregnancy, the uterus contracts irregularly to strengthen itself in preparation for childbirth. These are known as Braxton Hicks contractions or false labor. Progesterone from the placenta keeps these contractions from becoming labor contractions. The cervical os remains closed (not dilated), and the wall of the cervix remains thick (not effaced). A mucus plug in the cervical os keeps out microorganisms. Late in the pregnancy, the head of the fetus drops into the birth position within the mother’s pelvis. This process is known as engagement. (It is also known as lightening because it eases the mother’s shortness of breath.) The fetus usually assumes a head-down position. The head becomes the presenting part (part of the body that will go first through the birth canal). This is a cephalic presentation. Any part of the head can be the presenting part, but most commonly it is the top of the head, and this is a vertex presentation . Sometime between 38 and 42 weeks’ gestation, labor begins. The weight of the fetus presses on the cervix and vagina. This causes the cervix to begin to dilate and stimulates the release of oxytocin from the posterior pituitary gland. The uterus itself also produces oxytoxin. Oxytocin causes the uterus to contract regularly. The cervix softens as collagen fibers in its wall break down. This is known as cervical ripening. The process of labor and childbirth is known as parturition. It is divided into three stages: 1. First stage of labor. Uterine contractions occur about every 30 minutes, increasing in intensity and duration. Cervical dilation (widening of the cervical os) progresses from 0 cm to 5 cm, and effacement (thinning of the cervical wall) progresses from 0 percent to 50 percent. Rupture of the membranes (ROM) occurs, and this releases amniotic fluid. As the uterine contractions intensify, the mother may receive epidural anesthesia to help control the pain. After 8 to 20

hours of labor, the cervix is completely dilated at 10 cm and 100% effaced, and the mother is transferred to the delivery room. 2. Second stage of labor. The uterine contractions have brought the head of the fetus into the vagina. The mother is encouraged to push by holding her breath to raise the intra-abdominal pressure. Crowning occurs when the top of the head is visible at the vaginal introitus. The head is delivered, and after several more uterine contractions, the shoulders and the rest of the body are delivered. The newborn is placed on the mother’s abdomen while the umbilical cord is clamped and cut. 3. Third stage of labor. The placenta is delivered about 30 minutes after the birth. The placenta is also known as the afterbirth. Oxytocin causes the uterus to contract to stop blood flow from the raw surfaces where the placenta pulled away. The obstetrician sutures up the episiotomy, if one was performed. The placenta and umbilical cord are sent to pathology for examination. Blood in the umbilical cord is rich in stem cells and can be used for stem cell transplantation. For the newborn, the period of time after birth is the postnatal period. For the mother, the period of time after birth is known as postpartum . The uterus gradually shrinks in size, a process known as involution. Small amounts of blood, tissue, and fluid, known as lochia, continue to flow from the uterus for a week until all of the endometrial lining is shed. Lactation is the production of milk by the breasts when stimulated by the hormone prolactin from the anterior pituitary gland in the brain. After birth, when the newborn cries or sucks, oxytocin secreted by the posterior pituitary gland causes smooth muscles around the lactiferous lobules to contract and expel milk for breastfeeding. This is known as the let-down reflex. The first milk, colostrum, is a thick, yellowish fluid. By the third day, the colostrum is replaced by regular breast milk that is thin and white.

The Newborn A newborn who is between 38 and 42 weeks’ gestation is a term neonate. A newborn between 28 and 37 weeks’ gestation is preterm or premature, a reference to the maturity of the internal organs and their ability to function. Because the date of conception is not always known, the gestational age of a newborn is an estimate. The skin of the newborn is covered with vernix caseosa , a thick, white, cheesy substance that protects the skin from amniotic fluid in the uterus. The head can exhibit molding, a temporary elongated reshaping of the cranium that occurs as the head passes through the mother’s bony pelvis. On the top of the head, the anterior fontanel or soft spot is a soft area that bulges when the newborn cries because it is only covered by a layer of fibrous connective tissue, not by bone. There is also a smaller posterior fontanel at the back of the head. The fontanels allow the brain to grow before the bones fuse together. The newborn’s face, hands, and feet are often bluish, a temporary condition known as acroc...