Female anatomy reproductive system PDF

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FEMALE REPRODUCTIVE ANATOMY AND PHYSIOLOGYI. The External Reproductive OrgansA. Mons Pubis or Veneris  pad of fat which lies over the symphysis pubis covered by skin and at puberty, by short hairs  protects the surrounding delicate tissues from trauma.B. Labia Majora (Labium majus)  two folds of ...

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FEMALE REPRODUCTIVE ANATOMY AND PHYSIOLOGY

I.

The External Reproductive Organs

Figure 1.1 The external female genitalia or the vulva.

A. Mons Pubis or Veneris  pad of fat which lies over the symphysis pubis covered by skin and at puberty, by short hairs  protects the surrounding delicate tissues from trauma. B. Labia Majora (Labium majus)  two folds of skin with fat underneath; contain Bartholin’s glands (believed to secrete a yellowish mucus which acts as a lubricant during sexual intercourse.  The openings of the Bartholin’s glands are located posteriorly on either side of the vagina orifice. C. Labia Minora (Labium minus) – two thin folds of delicate tissues; form an upper fold encircling the clitoris (called the prepuce) and unite posteriorly (called the fourchetes, which is highly sensitive to manipulation and trauma that is why it is often torn during a woman’s delivery.) D. Clitoris – It is a small (approximately 1 to 2 cm), rounded organ of erectile tissue at the forward junction of the labia minora., which is comparable to the penis in its being

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extremely sensitive. It also serves as a landmark for catheterization. It is sensitive to touch and temperature and is the center of sexual arousal and orgasm in the female. Prepuce of clitoris - is a fold of skin that surrounds and protects the glans of the clitoris. It also covers the external shaft of the clitoris and develops as part of the labia minora. Furhtermore, it is homologous with the foreskin (equally called prepuce) in male genitals. Vestibule of vagina – narrow space seen when the labia minora are separated. Urethral Meatus – external opening of the urethra; slightly behind and to the side are the openings of the Skene’s glands (which are often involved in infections of the external genitalia). Vaginal opening /Introitus – external opening of the vagina, covered by a thin membrane (called hymen) in virgins. Hymenal caruncle- they are ragged edges of the hymen commonly seen in sexually active women. Skene's glands/ducts (paraurethral glands/ducts) – There are two of these and are located just lateral to the urinary meatus, one on each side. The ducts open into the urethra. Bartholin gland/ ducts (vulvovaginal glands)-- are located just lateral to the vaginal opening on both sides. Their ducts open into the distal vagina.

Note: Secretions from both of these Skenes’s and Bartholin’s glands help to lubricate the external genitalia during coitus. The alkaline pH of their secretions helps to improve sperm survival in the vagina. Both Skene's glands and Bartholin's glands may become infected and produce a discharge and local pain. L. Vestibular fossa (navicular fossa)- is a boat-shaped depression between the vagina/hymen and the frenulum labiorum pudendi. M. Perineum – area from the lower border of the vaginal orifice to the anus; contains the muscles (e.g., pubococcygeal and levator ani) which support the pelvic organs, the arteries that supply blood and the pudendal nerves which are important during delivery under anesthesia. II.

The Internal Reproductive Organs

Figure 1.2 Anterior view of female reproductive organs indicating the relationship of fallopian tubes and body of the uterus.

A. Vagina – a 3-4 inch long dilatable canal located between the bladder and the rectum; contains rugae (which permit considerable stretching without tearing); passageway for menstrual discharges, copulation and fetus. CBQ B. Uterus – hollow pear-shaped fibromuscular organ 3 inches long, 2 inches wide, 1 inch thick, and weighing 50-60 grams in a non-pregnant woman; hold in place by broad ligaments (from sides of the uterus to pelvic wall; also hold Fallopian tubes and ovaries in place) and round ligaments (from sides of uterus to mons pubis); abundant blood supply from uterine and ovarian arteries; composed of three muscle layers (perimetrium, myometrium, and endometrium). Consists of three parts: corpus (body) – upper portion with triangular part called fundus; isthmus – area between corpus and cervix which forms part of the lower uterine segment; and, - cylindrical portion. Organ of menstruation, site of implantation and retainment and nourishment of the products of conception. Main support comes from cardinal ligaments C. Fallopian Tubes – 4 inches long from each side of the fundus; widest part (called ampulla) spreads into fingerlike projections (called fimbriae). Responsible for transport of mature ovum from ovary to uterus; fertilization takes place in its outer third or outer half. D. Ovaries – almond-shaped, dull white sex glands near the fimbriae, kept in place by ligaments. Produce, mature and expel ova and manufacture estrogen and progesterone. III. The Pelvis - although not a part of the Female Reproductive Organs but of the skeletal system, is a very important body part of pregnant women. A. Structure 1. 2 Os Coxae/Innominate bones – made up of: a. Ilium – upper, extended part; curved upper border is the iliac crest. b. Ischium – under part; when sitting, the body rests on the ischial tuberosities; ischial spines are important landmarks. c. Pubes – front part; join to form an articulation of the pelvis called the symphysis pubis. 2. Sacrum – wedge-shaped, form the back part of the pelvis. Consists of 5 fused vertebrae, the first having a prominent under margin called the sacral promontory. Articulates with the ilium, the sacroiliac joint. 3. Coccyx – lowest part of the spine; degree of movement between sacrum and coccyx, made possible by the third articulation of the pelvis called sacrococcygeal joint which allows room for delivery of the fetal head. B. Divisions – set apart by the linea terminalis, (pelvic brim, ileopectineal line) and imaginary line from the sacral promontory to the ilia on both side to the superior portion of the symphysis pubic. 1. False pelvis – superior half formed by the ilia. Offers landmarks for pelvic measurements; supports the growing uterus during pregnancy; and directs the fetus into the true pelvis near the end of gestation. 2. True pelvis – inferior half formed by the pubis in front, the ilia and the ischia on the sides and the sacrum and coccyx behind. Made up of three parts: a. Inlet – entranceway to the true pelvis. Its transverse diameter is wider than its anteroposterior diameter. Thus: Transverse diameter = 13.5 cm Anteroposterior diameter = 11 cm Right and left oblique diameters = 12.75 cm b. Cavity – space between the inlet and outlet c. Outlet – inferior portion of the pelvis bounded in the back by the coccyx, on the sides by the ischial tuberosities and in front by the inferior aspect of

the symphysis pubis and the pubic arch. Its anteroposterior (AP) diameter is wider than its transverse diameter. C. Types/Variations 1. Gynecoid – “normal female pelvis. Inlet is well rounded forward and back. Most ideal for childbirth. 2. Anthropoid – transverse diameter is narrow, AP diameter is larger than normal. 3. Platypelloid – inlet is oval, AP diameter is shallow 4. Android – “male” pelvis. Inlet has a narrow, shallow posterior portion and pointed anterior portion. D. Measurements 1. External – suggestive only of pelvic site. a. Intercristal – distance between the middle points of the iliac crests. Average = 28 cm. b. Interspinous – distance between the anterosuperior iliac spines. Average = 25 cm. c. Intertrochanteric – distance between the trochanters of the femur. Average = 31 cm. d. External conjugate/Daudelocque’s – the distance between the anterior aspect of the symphysis pubis and depression below L5. Average = 18-20 cm. 2. Internal – give the actual diameters of the inlet and outlet a. Diagonal conjugate – distance between sacral promontory and inferior margin of the symphysis pubis. Average = 12.5 cm. b. True conjugate/conjugata vera – distance between the anterior surface of the sacral promontory and the superior margin of the symphysis pubis. Very important measurement because it is the diameter of the pelvic inlet. Average = 10.5 - 11 cm. c. Bi-ischial diameter/tuberischial – transverse diameter of the pelvic outlet. Is measured at the level of the anus. Average = 11 cm IV. Feedback Mechanism of Menstruation A. General Considerations 1. 300,000 – 400,000 immature oocytes per ovary are present at birth (ware formed during the first 5 months of intrauterine life); many, however, degenerate and atrophy (process called atresia). About 300 – 400 mature during the entire reproductive cycle of women. 2. Ushered in by the menarche, (first menstruation in girls) and ends with menopause (permanent cessation of menstruation; no more functioning oocytes in the ovaries). Age of onset and termination vary widely, depending on heredity, racial background, nutrition and climate. 3. Normal period (days when there is menstrual flow) lasts for 3-6 days; menstrual cycle (from first day of menstrual period to first day of next menstrual period) maybe anywhere from 25-35 days, but accepted average length in 28 days. 4. Anovulatory states after menarche not unusual because of immaturity of feedback mechanism (anovulatory states occur also in pregnancy, lactation and related disease conditions). 5. Associated terms: a. Amenorrhea – temporary cessation of menstrual flow b. Oligomenorrhea – markedly diminished menstrual flow, nearing amenorrhea c. Menorrhagia – excessive bleeding during regular menstruation

d. Metrorrhagia – bleeding at completely irregular intervals e. Polymenorrhea – frequent menstruation occurring at intervals of less than three weeks 6. Body structures involved: a. Hypothalamus b. Anterior pituitary gland c. Ovary d. Uterus 7. Hormones which regulate cyclic activities: a. Follicle-stimulation hormone (FSH) b. Luteinizing hormone (LH) 8. Effects of estrogen in the body: a. Inhibits production of FSH b. Causes hypertrophy of the endometrium c. Stimulates growth of the ductile structures of the breasts d. Increases quantity and pH of cervical mucus, causing it to become thin and watery and can be stretched to a distance of 10-13 cm. (Spinnbarkeit test of ovulation) 9. Effects of progesterone in the body: a. Inhibits production of LH b. Increases endometrial tortuosity c. Increases endometrial secretions d. Inhibits uterine motility e. Decreases muscle tone of gastrointestinal and urinary tracts f. Increases musculoskeletal motility g. Facilitates transport of the fertilized ovum through the Fallopian tubes h. Decreases renal threshold for lactose and dextrose i. Increases fibrinogen levels; decreases hemoglobin and hematocrit j. Increases body temperature after ovulation. Just before ovulation, basal body temperature decreases slightly (because of low progesterone level in the blood) and then increases slightly a day after ovulation (because of the presence of progesterone). B. Sequential Steps in the Menstrual Cycle 1. On the third day of the menstrual cycle, serum estrogen level is at its lowest. This low estrogen level serves as the stimulus for the hypothalamus to produce the Follicle-Stimulating Hormone Releasing Factor (FSHRF). 2. FSHRF is responsible for stimulating the Anterior Pituitary Gland ( APG) to produce the first of 2 hormones which regulate cyclic activities, the FollicleStimulating Hormone (FSH). 3. FSH, in turn, will stimulate the growth of an immature oocyte inside a primordial follicle by stimulating production of estrogen by the ovary. Once estrogen is produced, the primordial follicle is not termed Graafian follicle (The Graafian follicle, therefore, is the structure which contains high amounts of estrogen). 4. Estrogen in the Graafian follicle will cause the cells in the uterine endothelium to proliferate (grew very rapidly), thereby increasing its thickness to about eightfold. This particular phase in the uterine cycle, therefore, is called proliferative phase. In view of the change from primordial to Graafian follicle, it is also called the follicular phase. Because of the predominance of estrogen, it is also called the estrogenic phase. And since it comes right after the menstrual period, it is also called postmenstrual phase. And, it is also called the pre-ovulatory phase. 5. On the 13th day of the menstrual cycle, there is now a very low level of progesterone in the blood. This low serum progesterone level is then the stimulus for the Hypothalamus to produce the Luteinizing Hormone Releasing Factor (LHRF).

6. LHRF is responsible for stimulating the APG to produce the second hormone which regulates cyclic activity, the Luteinizing Hormone (LH). 7. LH, in turn, is responsible for stimulating the ovary to produce the second hormone produced by the ovaries, progesterone. 8. The increased amounts of both estrogen and progesterone pushes the now mature ovum to the surface of the ovary until, on the following day (the 14th day of the menstrual cycle), the Graafian follicle ruptures and releases the mature ovum, a process called ovulation. 9. Once ovulation is taken place, the Graafian follicle, because it now contains increasing amounts of progesterone is the Corpus Luteum. 10. Progesterone causes the glands of the uterine endothelium to become corkscrew or twisted in appearance because of the increasing amount of capillaries. Progesterone, therefore, is said to be the hormone designed to promote pregnancy because it makes the uterus nutritionally abundant with blood in order for the fertilize zygote to survive should conception take place. That is why this phase in the uterine cycle is what we call progestational phase. This phase in the uterine cycle is also called the secretory phase because it secretes the most important hormone in pregnancy. In view of the change from Graafian follicle, to Corpus Luteum, it is also called the luteal phase. Because it occurs just after ovulation, it is also called the postovulatory phase. And, it is also called the pre-menstrual phase. 11. Up until the 24th day of the menstrual cycle, if the mature ovum is not fertilized by a sperm, the amounts of hormones in the Corpus Luteum will start to decrease. The Corpus Luteum, turning white, is now called the corpus albicans and after 3-4 days, the thickened lining of the uterus produced by estrogen starts to degenerate and slough off and the capillaries rupture. And thus begins another menstrual period. C. Additional Information 1. When the ovary releases the mature ovum on the day of ovulation, sometimes a certain degree of pain in either the right or left lower quadrant is felt by the woman. This sensation is normal and is termed mittelschmerz. 2. The first 14 days of the menstrual cycle is a very variable period. The last 14 days of the menstrual cycle is a fixed period exactly 2 weeks after ovulation, menstruation will occur (unless a pregnancy has taken place) because the corpus luteum has a life span of only 2 weeks. Implication: when given options regarding the exact date of ovulation, choose two weeks before menstruation. 3. In a 28-day cycle, ovulation takes place on the 14 th day. In a 32-day cycle, ovulation takes place on the 18th day. In a 26-day cycle, ovulation takes place or the 12th day (Subtract 14 days from the cycle). 4. Menstruation can occur even without ovulation (as in women taking oral contraceptives). Ovulation can likewise occur even without menstruation (as in lactating mothers). PREGNANCY AND PRENATAL CARE I. Obstetric Terms in Statistical Data A. Birth rate – the number of births per 1,000 population B. Fetal death rate – the number of total deaths per 1,000 births. (both live births and stillbirths) C. Perinatal mortality rate – the number of deaths occurring between 28 weeks gestation until 6 days after birth D. Neonatal mortality rate – the number of neonatal (first 28 days of life) deaths per 1,000 live births

E. Infant mortality rate – the number of infant (first 12 months of life) deaths per 1,000 live births F. Maternal mortality rate – the number of deaths that occur as the direct result of the reproductive process per 10,000 live births II. Fertilization A. Definition: the union of the sperm and the mature ovum in the outer third or outer half of the Fallopian tube. B. General considerations: 1. Normal amount of semen per ejaculation = 3 – 5 cc = 1 teaspoon 2. Number of sperms in an ejaculate = 120 – 150 million/cc 3. Mature ovum is capable of being fertilized for 12-24 hours after ovulation. Sperms are capable of fertilizing even for 3-4 days after ejaculation 4. Normal life span of sperms = 7 days 5. Sperms, once deposited in the vagina, will generally reach the cervix within 90 seconds after deposition. 6. Reproductive cells, during gametogenosis, divide by meiosis (haploid number of daughter cells); therefore, they contain only 23 chromosomes (the rest of the body cells have 46 chromosomes). Sperms have 22 autosomes and 1 X sex chromosome or 1 Y sex chromosome; ova contain 22 autosomes and 1 X sex chromosome. The union of an X-carrying sperm and a mature ovum results in a baby girl (XX); the union of a Y-carrying sperm and a mature ovum results in a baby boy (XY). Important: Only fathers determine the sex of their children. III. Implantation Immediately after fertilization, the fertilized ovum or zygote stays in the Fallopian tube for 3 days, during which time rapid cell division (mitosis) is taking place. The developing cells are now called blastomere and when there are already 16 blastomeres, it is now terms a morula. In this morula form, it will start to travel (by ciliary action and peristaltic contractions of the Fallopian tube) to the uterus where it will stay for another 3-4 days. When there is already a cavity formed in the morula, it is now called blastocyst. Fingerlike projections, called trophoblasts, form around the blastocyst and these trophoblast are the once which will implant high on trophoblasts or posterior surface of the uterus. Thus, implantation, also called nidation, takes place about a week after fertilization. General Consideration: A. Once implantation has taken place, the uterine endothelium is now termed decidua B. Occasionally, a small amount of vaginal spotting appears with implantation because capillaries are ruptured by the implanting throphoblasts = implantation bleeding. Implication: this should not be mistaken for the Last Menstrual Period (LMP). Table 1. Outline of Trophoblast Differentiation N. Cytotrophoblast – the inner layer II. Syncytiotrophoblast – the outer layer containing fingerlike projections called chorionic villi: A. Langhan’s layer – believed to protect the fetus against Treponema Pallidum (etiologic agent of syphilis). Present only during the second trimester of pregnancy. B. Syncytial layer – gives rise to the fetal membranes: 1. Amnion – inner layer which gives rise to: a. Umbilical cord/funis – contains 2 arteries and one vein, which are supported by the Wharton’s jelly b. Amniotic fluid – clear, albuminous fluid in which the baby floats. Begins to form at 11-15 weeks gestation. Approximates water in specific gravity (1.007-1.025) and is neutral to slightly alkaline

(pH=7.0-7.25. Note: the higher the pH, the more alkaline; the lower the pH, the more acidic). Near term, is clear, colorless, containing little white specks of vernix caseosa and other solid particles. Produced at a rate of 500 ml in 24 hours and fetus swallows it at an equally rapid rate. By the 4th lunar month, urine is added to the amount of amniotic fluid. It is, therefore, derived chiefly from maternal serum and fetal urine. (Implication: a case of polyhydramnios = more than 1500 ml of aminiotic fluid, stems from inability of the fetus to swallow amniotic rapidly, as in Tracheoesophageal fistuli; while oligo-hydramnios = amniotic fluid less than 500 ml, results when kidneys are not functioning normally, as in congenital renal anomaly.) Also know as bag of waters (BOW), it serves the following purposes:  Protection: * Shields the fetus against blows or pressure on the mother’s abdomen * Protects the fetus against sudden change sin temperature because liquid changes temperature more slowly than air * Protects the fetus against certain infections  Diagnosis: * As in amniocentesis * Meconium-stained amniotic fluid means fetal distress  Aids in descent of the fetus during active labor...