Reproductive Systems - Anatomy, Spermatogenesis, Oogenesis - PDF

The Reproductive Systems Introduction Sexual Reproduction is the process in which organisms produce offspring by means of uniting gametes (sperm and egg) Male reproductive organs secrete androgen hormones, produce gametes (sperm), and facilitate fertilization Female reproduc...

The Reproductive Systems Introduction Sexual Reproduction is the process in which organisms produce offspring by means of uniting gametes (sperm and egg) Male reproductive organs secrete androgen hormones, produce gametes (sperm), and facilitate fertilization Female reproductive organs secrete female hormones, produce gametes (ova), facilitate fertilization and sustain growth of the embryo and fetus Similar parts in the male and female systems: o The gonads (the testes in males and ovaries in females) are the site for gamete production and hormone secretion o Various ducts store and transport gametes o Accessory sex glands produce secretions that protect the gametes and facilitate their movement. o Supporting structures assist the delivery of gametes (ex: penis in males, uterus in females) 2 Introduction Gynecology is the medical specialty that treats disorders and diseases of the female reproductive system Obstetrics focuses on the care of women during pregnancy Urology is the medical specialty that treats disorders of the urinary system. In addition, urologists treat disorders involving the male reproductive system. 3  The Reproductive Systems - Overview Male Reproductive System Female Reproductive System Female Reproductive Cycle Birth Control Methods and Abortion Development of the Reproductive Systems Aging and the Reproductive Systems Reproductive System Disorders 4 Male Reproductive System Anatomy Overview Male gonads are the testes (singular: testis) Ducts of the male reproductive system are the: o Ducts of the testis o Epididymis o Vas deferens (ductus deferens) o Ejaculatory ducts o Urethra Male accessory sex glands are the: o Seminal vesicles (2) o Prostate (1) o Bulbourethral glands (2) Male supporting structure are the penis , scrotum, and spermatic cord. 5 Testes A white fibrous capsule surrounding each testis called the tunica albuginea forms septa that divide each testis into 200-300 compartments called lobules o Each lobule contains 1-3 seminiferous tubules where sperm are produced 6  Spermatogenesis Spermatogenesis (sperm formation) begins at puberty and continues throughout life. In humans, spermatogenesis takes 65-75 days. Follicle-stimulating hormone (FSH) and testosterone stimulate spermatogenesis. Spermatogenesis starts with diploid (2n) stem cells called spermatogonia and ends with haploid (n) spermatozoa (aka sperm). Thus, meiosis is involved. Spermatogenesis occurs in the seminiferous tubules: it starts in the outer region of each tubule and as the cells 7 Basement membrane of Spermatogenesis seminiferous tubule Some spermatogonia remain as precursor stem cells Superficial moves from Spermatogonium 2n 2n outer region of Some spermatogonia pushed away from Mitosis 2n tubule to inner basement membrane Differentiation region (lumen) Primary spermatocyte 2n DNA replication, tetrad formation, and crossing-over Meiosis I Note the different MEIOSIS Secondary spermatocytes names as the gametes n n Each chromosome has develop and the Meiosis II two chromatids cytoplasmic bridge Cytoplasmic Spermatids bridge n n n n SPERMIOGENESIS Spermatozoa n n n n Deep Lumen of seminiferous tubule 8 Spermatozoa Each day about 300 million sperm complete the process of spermatogenesis. A sperm contains several structures that are highly adapted for reaching and penetrating a secondary oocyte 2 major parts of sperm: o Head contains: Nucleus - contains 23 highly condensed chromosomes. Acrosome - cap-like vesicle covering the anterior two-thirds of the nucleus. It is filled with enzymes (hyaluronidase and proteases) that help a sperm to penetrate a secondary oocyte to bring about fertilization o Tail contains 4 parts: neck, middle piece, principal piece, and end piece. The middle piece contains mitochondria which provide the energy (ATP) for locomotion. 9 Hormone control of spermatogenesis What happens at puberty that makes spermatogenesis begin? o Unknown initiating factors cause hypothalamus to increase secretion of gonadotropin-releasing hormone (GnRH), which in turn, increases release of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) from anterior pituitary. LH stimulates Leydig cells, which are located between seminiferous tubules, to secrete testosterone. Testosterone directly stimulates the final steps of spermatogenesis. FSH and testosterone stimulate Sertoli cells to release androgen- binding protein (ABP), which binds to testosterone, ensuring that testosterone levels remain high in the seminiferous tubules. Thus by promoting ABP formation, FSH indirectly stimulates spermatogenesis. Once the degree of spermatogenesis needed for fertility has been achieved, Sertoli cells release inhibin, which inhibits FSH secretion by the pituitary. 10 Hypothalamus Hormonal control GnRH Testosterone decreases release of GnRH and LH Anterior pituitary of spermatogenesis Inhibin decreases Gonadotroph release of FSH Note the feedback inhibition by Together with LH stimulates inhibin and testosterone testosterone, FSH LH testosterone FSH stimulates secretion spermatogenesis Inhibin Testosterone ABP Spermatogenic cells Leydig cells secrete Sertoli cells secrete Dihydrotestosterone testosterone androgenbinding (DHT) protein (ABP) Key: LH FSH Testosterone LH receptor FSH receptor Androgen receptor Male pattern of development (before birth) Enlargement of male sex organs and expression of male secondary sex characteristics (starting at puberty) Anabolism (protein synthesis) 11 Other androgen effects (besides spermatogenesis) Prenatal development prenatal secretion of testosterone assists testicular descent and, via conversion to dihydrotestosterone (DHT), development of male external genitals Testosterone and DHT at puberty leads to development of male sexual characteristics: enlargement of male sex organs and promotion of secondary sex characteristics (male hair pattern, lower voice, etc). Development of sexual function androgens contribute to male sexual behavior. They also contribute to sex drive in both males and females. Stimulation of anabolism androgens are anabolic hormones: they stimulate protein synthesis. 12 Male reproductive system ducts After formation in the seminiferous tubules, sperm travel the following route to exit the body: 1. Straight tubules 2. Rete testis 3. Efferent ducts 4. Epididymis (or ductus epididymis) sperm maturation (gain motility and ability to fertilize an ovum) occurs here. May also store sperm for up to several months. 5. Vas deferens (or ductus deferens) 6. Ejaculatory ducts 7. Urethra 3 regions in order: prostatic, membranous, and spongy (penile). 13 Semen Semen is a mixture of sperm and seminal fluid. The volume of semen in a typical ejaculation is 2.5 5 milliliters (mL), with 50 150 million sperm per mL When the number falls below 20 million/mL, the male is likely to be infertile Some of the fluid portion is from the seminiferous tubules, but most of it is from the male accessory sex glands: seminal vesicles, prostate, and bulbourethral glands. 14 Male accessory sex glands Seminal vesicles secrete a viscous, alkaline fluid (mainly during ejaculation) which makes up 60% of the total semen volume. It contains fructose (for energy), prostaglandins (to stimulate smooth muscle contractions), and clotting proteins. o the alkalinity neutralizes the acidity of the male urethra and the female reproductive tract The prostate is a chestnut-sized gland that secretes about 25% of semen volume. Prostatic fluid is a milky, slightly acidic solution containing citric acid (for energy), acid phosphatase, and proteolytic enzymes (PSA and hyaluronidase) The are pea-sized glands inferior to the prostate. It secretes a protective alkaline mucus that decreases sperm damage in the urethra 15  Scrotum and Spermatic Cord The scrotum is the supporting structure for the testes o It consists of a sac of loose skin and superficial fascia that hangs from the root of the penis o The location and contraction of muscle fibers (dartos and cremaster muscles) regulates testicular temp to that required for sperm production (2-3oC below the core temp) Spermatic cord - supportive structure that ascends out of scrotum. Consists of: ductus deferens, testicular artery, veins (drain testes and carry testosterone to body), autonomic nerves, lymphatic vessels, and cremaster muscle 16 Inguinal canal The spermatic cord and ilioinguinal nerve (sensory to skin in area) pass through the inguinal canal, a passageway in the aponeuroses of the abdominal muscles (transversus abdominus, internal oblique, and external oblique muscles) o In women, the round ligament of the uterus and the ilioinguinal nerve pass through the inguinal canal 17 Penis Penis contains the urethra and is a passageway for the ejaculation of semen and the excretion of urine o It is cylindrical in shape and consists of a body, glans penis, and a root Penis is supported by the fundiform ligament (from the linea alba) and the suspensory ligament (from the pubic symphysis). Body of the penis is composed of three cylindrical masses of erectile tissue, each surrounded by fibrous tissue called the tunica albuginea o The two dorsolateral masses are the corpora cavernosa, and the smaller midventral mass is the corpus spongiosum (contains the spongy urethra and keeps it open during ejaculation) 18  The Male Sexual Response Upon sexual stimulation (visual, tactile, auditory, olfactory, or imagined), sacral parasympathetic fibers initiate and maintain an erection o Under the influence of nitric oxide released from parasympathetic neurons arteries that supply the penis dilate and blood enters a network of sinuses in the erectile tissue; NO also causes the smooth muscle within the erectile tissue to relax, resulting in widening of the blood sinuses. After an erection, sympathetic stimulation is necessary for the rest of the sexual response, including ejaculation o The smooth muscle sphincter at the base of the urinary bladder must close, followed by semen being propelled into the penile portion of the urethra (emission) o Powerful peristaltic contractions culminate in the release of semen from the urethra to the exterior 19 Female Reproductive System Anatomy Overview Female gonads are the ovaries Ducts of the female reproductive system are the: o Uterine tubes (fallopian tubes) Female accessory sex glands are the: o o glands o Lesser vestibular glands Female supporting structure are the uterus, vagina, and vulva (external genitals) 20 Ovaries The ovaries are oval-shaped organs held in place in the pelvic cavity by the suspensory ligaments (for pelvic wall attachment), and the ovarian ligaments (provides an attachment to the side wall of the uterus) The histology of the ovaries reveals the following parts: o The germinal epithelium covers the surface of the ovary, but does not give rise to ova those cells arise from the yolk sac and migrate to the ovaries o The ovarian cortex contains the ovarian follicles o The ovarian medulla contains blood vessels, lymphatic vessels and nerves 21  Ovaries The primary role of the ovaries are to produce mature 2o oocytes (female gametes) and release one (ovulation) during each monthly ovarian cycle o another important function of the ovaries is to secrete the female hormones estrogen, progesterone, inhibin, and relaxin 22 Uterine Tubes After receiving the 2o oocyte at the infundibulum the uterine tubes provide a site for fertilization. If fertilization occurs, the 2o oocyte becomes an ovum (mature egg) and then the tubes transport the ovum to the uterus. The uterine tubes also have an ampulla (widest, longest part) and an isthmus (short part that joins uterus) 23 Uterus The uterus is a pear-shaped organ situated between the urinary bladder and the rectum. Functions include: o Pathway for sperm deposited in the vagina to reach the uterine tubes o Site of implantation for an ovum and the site of fetal development during pregnancy. o During reproductive cycles when implantation does not occur, the uterus is the source of menstrual flow The broad ligaments provide side-to-side and rotation support for the uterus by attaching to each side of the pelvic cavity. The uterosacral ligaments attach the uterus to the sacrum. 24  Uterus Anatomical subdivisions of the uterus include: o Fundus - dome-shaped superior portion. o Body - central portion that tapers to a narrow isthmus. The interior of the body is called the uterine cavity. o Cervix inferior portion; inside is cervical canal with an internal os and external os that opens into the uterine cavity and vagina, respectively 25 Uterus The wall of the uterus consists of 3 layers (from deep to superficial): o Endometrium includes inner stratum functionalis, which is shed during menstruation, and outer stratum basalis, which is permanent and gives rise to new functionalis layer. o Myometrium includes inner and outer layers with muscle running longitudinally and middle layer with muscle in circular orientation. o Perimetrium a part of visceral peritoneum. 26 Vagina The vagina is a fibromuscular canal lined with mucous membrane that extends from the exterior of the body to the uterine cervix. It is composed of both longitudinal and circular muscle, and has 3 basic functions: o Serve as a passageway for menstrual flow o Receptacle for penis during sexual intercourse. o Form the lower birth canal 27  Vulva The vulva (or pudendum) - female external genitalia; refers to the: o Mons pubis (created by adipose tissue) o Labia majora (outer limits of vulva) and labia minora (covers the vestibule) o Clitoris contains erectile tissue. o Bulb of the vestibule deep to labia, contains erectile tissue o Vestibule - area between the labia minora, it includes hymen, vaginal orifice, external urethral 28 Vulva Glands of the vestibule include: o their ductal openings flank the external urethral orifice. They secrete mucus. Homologous to prostate gland in males. o On either side of the vaginal orifice itself are the greater which open by ducts into a groove between the hymen and labia minora. They produce a small quantity of lubricating mucus during sexual arousal. Homologous to bulbourethral glands in males. o Several lesser vestibular glands also open into the vestibule. 29 Perineum The perineum denotes the diamond-shaped area medial to the thighs and buttocks of both females and males. It contains the external genitalia and anus. A transverse line drawn from the ischial tuberosities divides the perineum into an anterior urogenital triangle and a posterior anal triangle. 30  Mammary Glands Within each breast is a mammary gland, a modified sudoriferous gland that produces milk. Each mammary gland contains 15 20 lobes divided into lobules. o Each lobule is composed of milk- secreting glands called alveoli. Milk produced in the alveoli move through various ducts before exiting the breast at lactiferous ducts located in the nipples. 31 The Female Sexual Response As in the male, the initiation of the sexual response results in stimulation of sacral parasympathetic fibers and nitric oxide dilation of the erectile tissues in this case, of the clitoris o Orgasm occurs at the peak of the plateau phase of the sexual response. Sexual climax culminates in a sympathetic discharge, accompanied by quick cycles of muscle contraction in the lower pelvic muscles. 32 Oogenesis and follicular development The formation of gametes in the ovaries is termed oogenesis. In contrast to spermatogenesis, which begins in males at puberty, oogenesis begins in females before they are even born (the ovarian The gametes develop inside clusters of cells. A gamete plus the cluster of cells surrounding it is called a follicle. While a gamete is undergoing oogenesis, the entire follicle is also changing this is termed follicular development. o They are the source for estrogens and progesterone. 33  Oogenesis and follicular development During early fetal development, primordial germ cells migrate from the yolk sac to the ovaries where they differentiate into oogonia o Oogonia are diploid (2n) stem cells that divide mitotically to produce millions of themselves. Prior to birth, most oogonia degenerate (known as atresia), though a few develop into larger cells called 1o oocytes that enter prophase of meiosis I during fetal development but do not complete that phase until after puberty. o During this arrested stage of development, each 1o oocyte is surrounded by a single layer of flat follicular cells and the entire structure is called a primordial follicle. 34 THE BIG PICTURE current location: at birth, a baby girl has 200,000 to 2 million primary oocytes per ovary, each within a primordial follicle. 35 Oogenesis and follicular development At puberty, later. By this time, the number of primary oocytes has fallen to ~40,000. Each month from puberty to menopause, LH and FSH secreted by the anterior pituitary will stimulate several primordial follicles to develop. A few of the primordial follicles will develop into primary follicles. o A primary follicle differs from a primordial follicle in that it has: Several layers of cuboidal and low-columnar cells called granulosa cells that surround the primary oocyte. A clear glycoprotein layer, the zona pellucida, between the primary oocyte and the granulosa cells. A stromal cell layer surrounding the basement membrane called the theca folliculi. 36  THE BIG PICTURE current location: Each month starting at puberty some of the primordial follicles will develop into primary follicles. 37 Oogenesis and follicular development With continuing maturation, the primary follicles develop into secondary follicles (note the secondary follicle still contains a primary oocyte). Secondary follicles differ from primary follicles in that: o The theca has differentiated into 2 layers: a vascularized internal layer called the theca interna an outer stromal cell/collagen layer called the theca externa. o Granulosa cells have secreted fluid creating a cavity called the antrum. o The innermost layer of granulosa cells is firmly attached to the zona pellucida and is now called the corona radiata. 38 THE BIG PICTURE current location: The primary follicle has become a secondary follicle, but inside is still a primary oocyte. 39  Oogenesis and follicular development One of the secondary follicles in one of the ovaries eventually outgrows the others to become the dominant follicle. This dominant follicle will grow larger and turn into a mature (graafian) follicle. o It is inside this follicle that the primary oocyte will finally complete meiosis I, yielding two haploid (n) cells. One of these cells is bigger than the other and is called the secondary oocyte. The smaller one is called the first polar body. o Once formed, the secondary oocyte begins meiosis II, but stops at metaphase. 40 THE BIG PICTURE current location: One secondary follicle is dominant and becomes mature follicle. The primary oocyte inside finishes meiosis I. 41 Oogenesis and follicular development Soon after the secondary oocyte stops at metaphase II, the mature follicle ruptures and releases the oocyte. This is ovulation. The secondary oocyte is swept into the uterine tube. If sperm are present and penetrate the oocyte (fertilization), meiosis II resumes (if no fertilization, then the oocyte degenerates). The completion of meiosis II by the secondary oocyte results in one larger cell (the ovum) and one smaller cell (second polar body). The nuclei of the sperm and ovum then fuse, yielding a diploid (2n) cell (zygote) that will eventually divide and become the fetus. o Note the first polar body may or may not undergo meiosis II also. Thus, there could be 1 ovum and either 2 or 3 polar bodies. 42  THE BIG PICTURE current location: The secondary oocyte only completes meiosis II (and yields an ovum) if fertilization by a sperm occurs. 43 Female Reproductive Cycle From menarche (first menses) to menopause, nonpregnant females exhibit cyclical changes in the ovaries (ovarian cycle) and uterus (uterine cycle, aka menstrual cycle). Each cycle takes around 28 days. The ovarian cycle involves the production/release of a secondary oocyte from the ovaries as described previously, while the uterine cycle involves preparation of the uterine lining to receive a fertilized ovum. Hormones secreted by the hypothalamus, anterior pituitary, and ovaries control the main events (more in a moment). Note the term encompasses the ovarian and uterine cycles, the hormonal changes that regulate them, and the related cyclical changes in the breasts and cervix. 44 Hormonal Regulation of the Female Reproductive Cycle GnRH secreted by the hypothalamus controls the ovarian and uterine cycles; it stimulates the release of FSH and LH by the anterior pituitary. FSH initiates follicle growth, while LH stimulates further follicle development. Together they also stimulate the follicles to secrete estrogens. At midcycle, an LH surge triggers ovulation and promotes formation of the corpus luteum graafian follicle and the key producer of progesterone, relaxin, and inhibin. 45  Hormonal Regulation of the Female Reproductive Cycle Estrogens secreted by follicles have severe key effects: o Help develop reproductive structures, secondary sex characteristics (broad pelvis, female hair pattern, etc.), and breasts. o Increase protein anabolism (ex. build strong bones) o Lower blood cholesterol may be cause of decreased coronary disease rate. o Moderate estrogen levels decrease release of GnRH, LH, and FSH. Progesterone, secreted mainly by cells of corpus luteum, is the principal hormone responsible for maturation of the uterine lining (endometrium), as well as an important player in stimulating breast development. In addition, progesterone inhibits GnRH and LH through a negative feedback loop. 46 Hormonal Regulation of the Female Reproductive Cycle Relaxin is released by the corpus luteum; it relaxes the myometrium during pregnancy and the pubic symphysis at the end of pregnancy (in preparation for delivery). Inhibin is released by granulosa cells of growing follicles, and then in large amount by the corpus luteum; it inhibits secretion of FSH (and to a lesser extent LH) from the anterior pituitary. 47 Phases of the Female Reproductive Cycle The are 4 phases to the female reproductive cycle -day cycle): o Menstrual phase days 1 to 5 o Preovulatory phase days 6 to 13 o Ovulation day 14 o Postovulatory phase days 15 to 28 During these phases, important events are occurring simultaneously in the ovaries and uterus. 48 Phases of the Female Reproductive Cycle Menstrual phase days 1 to 5 o Ovaries FSH causes primordial follicles to become primary follicles and then secondary follicles. o Uterus menstrual flow of 50-150 mL of blood, tissue fluid, mucus, and epithelial cells from the endometrium. Declining levels of progesterone and estrogens stimulate prostaglandin release, which causes uterine spiral arteries to constrict. This, in turn, causes stratum functionalis layer of endometrium to slough off (endometrial thickness = 2-5 mm) 49 Phases of the Female Reproductive Cycle Preovulatory phase days 6 to 13 o Ovaries dominant follicle emerges and secretes estrogens and inhibins, which decrease FSH secretion, causing other follicles to degenerate. Dominant follicle becomes mature follicle. o Uterus estrogens from growing follicles stimulate repair and growth of the endometrium, causing it to double in thickness (thickness = 4-10 mm). 50 Phases of the Female Reproductive Cycle Ovulation day 14 o Mature follicle ruptures releasing secondary oocyte. o As noted, an LH surge triggers ovulation. This surge is caused by high levels of estrogens during the last part of the preovulatory phase. While low and moderate levels of estrogens inhibit GnRH and LH release, high levels actually stimulate their release. 51 Phases of the Female Reproductive Cycle Postovulatory phase days 15 to 28. o Ovaries the ruptured mature follicle becomes a corpus luteum. If fertilization did not occur, the corpus luteum degenerates after 2 weeks. With fertilization, it is human chorionic gonadotropin (hCG) produced by the chorion (a membrane surrounding the fetus) o Uterus progesterone and estrogens from corpus luteum cause growth of endometrial glands, endometrial vascularization and thickening (12-18 mm). Without fertilization, progesterone and estrogen levels fall and reproductive cycle starts again with menstruation. 52 Phases of the Female Reproductive Cycle note in addition to the 4 phases mentioned, there are names for specific phases of the ovarian and uterine cycles 53 Changes in concentration of anterior pituitary and ovarian hormones during female reproductive cycle LH Progesterone concentration Estrogens Hormone FSH Days 54  Birth Control Methods and Abortion Several methods of birth control are available, each with advantages and disadvantages. The only method of preventing pregnancy that is 100% reliable is total abstinence, avoidance of sexual intercourse. Methods of birth control include: o surgical sterilization (vasectomy, tubal ligation) o hormonal methods (oral contraception, the Norplant implant, Depo-Provera injection, the vaginal ring) o intrauterine devices (IUDs) o spermacides, barrier methods (condom, vaginal pouch, diaphragm, cervical cap) o periodic abstinence (rhythm method, sympto-thermal method) o coitus interruptus (withdrawal) Abortion is the premature expulsion of the products of conception from the uterus. Methods include induced abortion with medications (RU 486 or mifepristone) and/or surgical removal (vacuum aspiration, dilation and evacuation). 55 Birth control methods and their failure rates 56 Development of the Reproductive Systems The gonads develop from intermediate mesoderm and are differentiated into ovaries or testes by about the seventh week of fetal development. The internal reproductive systems of males develop from Wolffian ducts, while those of females develop from Mullerian ducts. Both types of ducts lie in close proximity to the developing gonads. The external genitalia remain undifferentiated until about 8 weeks. If dihydrotestosterone (DHT) is present, male genitals develop; if not, then female genitals. 57  Homologous Structures Equivalent male/female structures during fetal development o oocyte) minora paraurethral glands greater vestibular glands 58 Aging and the Reproductive Systems Aging - Females In females, the reproductive cycle normally occurs once each month from menarche, the first menses, to menopause, the last menses. o Between the ages of 40 and 50 the ovaries become less responsive to the stimulation of gonadotropic hormones from the anterior pituitary. As a result, estrogen and progesterone production decline, and follicles do not undergo normal development. o In addition to the symptoms of menopause, such as hot flashes, copious sweating, headache, vaginal dryness, depression, weight gain, and emotional fluctuations, with age females also experience increased incidence of osteoporosis, uterine cancer, and breast cancer. 59 Aging - Males In males, declining reproduction function is more subtle, with males often retaining reproductive capacity into their 80s or 90s. o In males, decreasing levels of testosterone decrease muscle strength, sexual desire, and viable sperm. o Prostate disorders are increasingly common with age, particularly benign hyperplasia. 60 Reproductive System Disorders Benign prostatic hyperplasia is an enlargement of the prostate gland (2-4 x normal size). It occurs in most men over age 60. It causes obstruction of urine flow and inability to completely empty the bladder Impotence is the inability to maintain erection long enough for sexual intercourse Primary infertility describes couples who have never been able to become pregnant after at least 1 year of unprotected sex 61 Reproductive System Disorders Menstrual Abnormalities o Amenorrhea is the absence of menstruation o Dysmenorrhea describes unusual menstrual discomfort (usually indicates an excess of prostaglandin secretion) o Disfunctional uterine bleeding (DUB) is abnormal uterine bleeding in the absence of organic disease (usually an estrogen/progesterone imbalance) o PMS (premenstrual syndrome) indicates a mild distress near end of postovulatory (luteal) phase Sexually transmitted diseases gonorrhea, syphilis, herpes, etc. Serious complications: salpingitis (incl. infertility), peritonitis. 62 The End