Reproductive System MCB247 2012.

Reproductive System MCB

Structures of the Reproductive System
Gonads: organs that produce gametes and hormones Ducts: receive and transport gametes Accessory glands: secrete fluids into ducts Perineal structures: collectively known as external genitalia The reproductive system ensures the continued existence of the human species by producing, storing, nourishing and transporting functional male and female reproductive cells called gametes. In both males and females, the ducts are connected to chambers and passageways that open to the outside. The structures involved make up the reproductive tract. Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

Structures of the Reproductive System
Male and Female Reproductive Systems Are functionally different Female produces one gamete per month Retains and nurtures zygote Male disseminates large quantities of gametes Produces 1/2 billion sperm per day

Male Reproductive Functions
Figure 28–1 The Male Reproductive System. The testis produce the male gametes, called spermatazoa, or sperm. Proceeding from a testis, the spermatozoa travel within the epididymis, the ductus deferens or vas deferens, the ejaculatory duct and urethra before leaving the body. The external genetalia consists of the scrotum, which encloses the testes and the penis. In males, the urethra extends from the urinary bladder to the tip of the penis. It is divided into prostatic, membranous and spongy regions. The male urethra is a passageway used by both the urinary and reproductive systems. The distal portion of the urethra passes through the distal portion of the penis forming the external urethral orafice. The anterior surface of the flaccid penis covers two cylindrical masses of erectile tissue: the corpa cavernosa which extend along the length of the penis. The erectile tissue within each corpus cavernosum surrounds a central artery, or deep artery of the penis. The relatively slender corpus spongiosum surrounds the penile urethra.

Figure 28–3 The Male Reproductive System in Anterior View. The spermatic cords are paired structures extending between the abdominopelvic cavity and the testes. Each spermatic cord consists of layers of fascia and muscle enclosing the ductus deferens and the blood vessels, nerves and lymphatic vessels that supply the testes. The blood vessels include the testicular artery and the testicular vein. Branches of the genitofemoral nerve from the lumbar plexus provide innervation. The ingual ligament runs from the anterior superior iliac spine of the ilium to the pubic tubercle of the pubic bone. Each spermatic cord begins at the entrance to the inguinal canal and descends into the scrotum. The scrotum is divided into two chambers by the scrotal septum. A raised thickening in the scrotal surface known as the raphe divides it in two. *because the scrotal cavities are separated by a partition, infection of inflammation of one testis does not normally spread to the other. The scrotum consists of a thin layer of skin and the underlying superficial fascia. The dermis contains a layer of smooth muscle, the dartos muscle. Resting muscle tone in the dartos muscle elevates the testes and causes the characteristic wrinkling of the scrotal surface. A skeletal muscle layer, the cremaster muscle, lies deep to the dermis. Contraction of the cremaster muscle during sexual arousal or in response to decreased temperature tenses the scrotum and pulls the testes closer to the body. *Normal development of spermatazoa in the testes requires temperatures of about 2°F, which is lower than elsewhere in the body. The cremaster and dartos muscles relax or contract to move the testes away from or toward the body as needed to maintain acceptable testicular temperatures. Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

Figure 28–10a The Ductus Deferens and Accessory Glands The secretions of the accessory glands, seminal glands (seminal vesicles), prostate gland, and bulbo-urethral glands join the spermatazoa in the ejaculatory ducts and urethra to form semen. Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

Figure 28–4 The Structure of the Testes. The tunica vaginalis lines the scrotal cavity and reduces friction between the opposing parietal (scrotal) and visceral (testicular) surfaces. Deep to the tunica vaginalis covering the testis is the tunica albuginea, a dense layer of connective tissue. These fibers are continuous with those surrounding the adjacent epididymis and extend into the testis. There they form fibrous partitions, or septa, that converge toward the region nearest the entrance to the epididymis. The connective tissues in this region support the blood vessels and lymphatic vessels that supply and drain the testis, and the efferent ductules, which transport spermatazoa to the epididymis where they are stored. Sperm also undergo a maturation process in the epididymis, during which they gain they ability to swim forward and fertilize an egg. Final sperm maturation, known as capacitation, is completed in the female reproductive tract. The septa subdivide the testis into a series of lobules. Distributed among the lobules are approximately 800 slender, tightly coiled seminiferous tubules. Sperm production occurs within these tubules. *A typical testis contains nearly one-half mile of seminiferous tubules. Straight tubules are extensively interconnected, forming a maze of passageways known as the rete testis. Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

Five Cells of Spermatogenesis Spermatogonia (stem cells) divide by mitosis to produce two daughter cells: One remains as spermatogonium Second differentiates into primary spermatocyte Primary spermatocytes begin meiosis and form secondary spermatocytes Secondary spermatocytes differentiate into spermatids (immature gametes) Spermatogenesis is the process of spermatazoa formation. It begins at the outmost layer of cells in the seminiferous tubules and proceeds toward the lumen. At each step in this process, the daughter cells move closer to the lumen. Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

Five Cells of Spermatogenesis Spermatids: Differentiate into spermatozoa 5. Spermatozoa: Lose contact with wall of seminiferous tubule Enter fluid in lumen Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

Figure 28–5d The Seminiferous Tubules: Stages in Spermatogenesis. If we zoom in on the seminiferous tubules, we can see the different stages of spermatogenesis. Each seminiferous tubule contains spermatagonia, spermatocytes at various stages of meiosis, spermatids, spermatazoa and large nurse cells. Nurse cells are also known as sertoli cells and they provide a microenvironment that supports spermatogenesis. Interstitial, or leydig cells, produce androgens, primarily testosterone. The seminiferous tubules are isolated from general circulation by a blood-testis barrier, comparable in function to the blood-brain barrier. *This barrier prevents passage of cytotoxic agents or cells of the immune system into the tubules where they could cause damage to the sperm. Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

Figure 28-7 Spermatogenesis
spermatagonia Mitosis of spermatogonium Each division of a diploid spermatogonium produces two daughter cells. One is a spermatogonium that remains in contact with the basement membrane of the tubule, and the other is a primary spermatocyte that is displaced toward the lumen. Primary spermatocyte (diploid) Meiosis I DNA replication Prior to the start of Meiosis I, each primary spermatocyte contains 46 individual chromosomes. At the end of meiosis I, the daughter cells are called secondary spermatocytes. Every secondary spermatocyte contains 23 chromosomes, each of which consists of a pair of duplicate chromatids. Primary spermatocyte in late Prophase I Synapsis and tetrad formation Secondary spermatocytes Meiosis II Here is a diagram of what’s going on in the nucleus during spermatogenesis. Meiosis is a specialized form of cell division involved only in the production of gametes. In humans, gametes contain 23 chromosomes, half the amount found in somatic cells. As a result, the fusion of the nuclei of a male gamete and female gamete produces a cell that has the normal number of chromosomes (46), rather than twice that number. In the seminiferous tubules, meiotic divisions that begin with primary spermatocytes produce spermatids, the undifferentiated male gametes. Spermatids (haploid) The secondary spermatocytes soon enter meiosis II, which yields four haploid spermatids, each containing 23 chromosomes. For each primary spermatocyte that enters meiosis, four spermatids are produced. Spermiogenesis (physical maturation) In spermiogenesis, the last step of spermatogenesis, each spermatid matures into a single spermatozoon, or sperm. The process of spermiogenesis takes roughly 5 weeks to complete. Spermatozoa (haploid) 12

Figure 28–8a Spermiogenesis and Spermatozoon Structure. Each spermatazoon has four distinct regions: head, neck, middle piece and tail. The head is a flattened ellipse containing a nucleus with densely packed chromosomes. At the tip of the head is the acrosome, a cap-like compartment containing enzymes essential to fertilization. During spermiogenesis, saccules of the spermatid’s Golgi apparatus fuse and flatten into an acrosomal vesicle, which ultimately forms the acrosome of the spermatozoon. A short neck attaches the head to the middle piece. The mitochondrial spiral in the middle piece is full of mitochonria whose activity provide the ATP requried to move the tail. The tail is a flagellum that propels the spermatozoa forward in a whiplike, corkscrew motion. Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Colored SEM of human spermatozoa

4 Major Functions of Male Glands Activating spermatozoa Providing nutrients spermatozoa need for motility Propelling spermatozoa and fluids along reproductive tract Mainly by peristaltic contractions Producing buffers To counteract acidity of urethral and vaginal environments The testes produce physically mature spermatozoa that are not capable of successfully fertilizing an oocyte. The other portions of the male reproductive system are responsible for the functional maturation, nourishment, storage and transport of spermatozoa. Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

Hormones of the Reproductive System (male)
Table 28-1 Hormones of the Reproductive System (male) Hormone Source Regulation of Secretion Primary Effects Gonadotropin-releasing homrome (GnRH) Hypothalamus Inhibited by testosterone and possibly by inhibin Stimulated FSH secretion and LH synthesis Follicle-stimulating hormone (FSH) Anterior lobe of the pituitary gland Stimulated by GnRH, inhibited by inhibin Stimulates spermatogenesis and spermiogenesis through effects on nurse cells Lutinizing hormone (LH) Stimulated by GnRH Stimulates interstitial cells to secrete testosterone

Hormones of the Reproductive System (male)
Table 28-1 Hormones of the Reproductive System (male) Hormone Source Regulation of Secretion Primary Effects Androgens (primarily testosterone) Interstitial cells of testes Stimulated by LH Establish and maintain male secondary sex characteristics and sexual behavior; promote maturation of spermatazoa; inhibit GnRH secretion Inhibin Nurse cells of testes Stimulated by factors reseased by developing spermatazoa Inhibits secretion of FSH (and possibly of GnRH)

Ejaculate Is the volume of fluid produced by ejaculation Contains Spermatozoa Seminal fluid Enzymes The normal sperm count ranges from 20 million to 100 million spermatozoa per mililiter of semen Seminal fluid is a mixture of glandular secretions with a distinct ionic and nutrient composition. A typical sample of seminal fluid contains the combined secretions of the seminal glands (60%), the prostate gland (30%), the nurse cells and epididymis (5%) and the bulbo-urethral glands (less than 5%). Several important enzymes are in seminal fluid: 1. a protease that may help dissolve mucus in the vagina; 2. seminalplasmin, a prostatic enzyme that kills a variety of bacteria, including E. coli; 3. a prostatic enzyme that coagulates the semen within a few minutes of ejaculation by converting fibrinogen to fibrin; and 4. fibrinolysin, which liquefies the clotted semen after minutes. Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

Sexual Function Ejaculation Occurs as powerful, rhythmic contractions
In ischiocavernosus and bulbospongiosus muscles That stiffen penis Push semen toward external urethral opening Causes pleasurable sensations (orgasm) Followed by subsidence of erectile tissue (detumescence) Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

The Female Reproductive System
Figure 28–13 The Female Reproductive System. The female reproductive system produces sex hormones and functional gametes. It must also be able to protect and support a deveolping embryo and nourish a newborn infant. The main organs of the female reproductive system are the ovaries, uterine tubes (fallopian tubes), uterus and vagina, and the components of the external genetalia. As in males, there are a variety of accessory glands that release secretions into the reproductive tract. The ovaries are small, lumpy, almond-shaped organs near the lateral walls of the pelvic cavity and have three main functions: 1. production of immature female gametes, or oocytes; 2. secretion of female sex hormones, including estrogens and progestins; and 3. secretion of inhibin, involved in the feedback control of pituitary FSH production. The uterus provides mechanical protection, nutritional support, and waste removal for the developing embryo (weeks 1-8) and fetus (week 9-delivery). In addition, contractions of the muscular uterus are important in ejecting the fetus at birth. The peritonial covering the uterus is called the perimetrium. There are two layers of the uterine wall: the outer, muscular layer is called the myometrium and the inner, glandular layer is called the endometrium. The cervix is the inferor portion of the uterus that extends down to the vagina. The vagina is an elastic, muscular tube extending between the cervix and the exterior. The shallow recess surrounding the cervical protrusion is known as the fornix. The urethra opens into the vestibule just anterior to the vaginal entrance. The paraurethral glands discharge into the urethra near the external urethral opening. During sexual arousal, the greater vestibular glands, located on either side of the distal portion of the vagina, secrete into the vestibule. These mucous glands keep the area moist and lubricated. Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

Figure 28–14 The Ovaries and Their Relationships to the Uterine Tube and Uterus. The ovaries, uterine tubes and uterus are enclosed within an extensive mesentery known as the broad ligament. The uterine tubes run along the superior border of the broad ligament and open into the pelvic cavity lateral to the ovaries. The mesovarium, a thickened fold of mesentary, supports and stabilizes the position of each ovary. The ovarian ligament extends from the uterus, near the attachment of the uterine tube, to the medial surface of the ovary. The infundibulopelvic (suspensory) ligament extends from the lateral surface of the ovary past the open end of the uterine tube to the pelvic wall. The suspensory ligament contains the major blood vessels of the ovary: the ovarian artery and ovarian vein. The uterosacral igaments extend from the lateral surfaces of the uterus to the anterior face of the sacrum, keeping the body of the uterus from moving inferiorly and anteriorly Infundibulopelvic ligament Within the vagina, the distal end of the cervix forms a curving surface that surrounds the external os of the uterus. The vaginal wall contains a network of blood vessels and layers of smooth muscles. The vaginal lumen is lined by a nonkeratinized stratified squamous epithelium. In the relaxed state, this epithelium forms folds called rugae. Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

Figure 28–18a The Uterus. The uterine tube is a hollow, muscular cylinder and is divided into three segments. The infundibulum is the end closest to the ovary forms an expanded funnel with numerous finger-like projections that extend into the pelvic cavity called fimbriae. Fibriae drape over the surface of the ovary, but there is no physical connection between the two structures. The ampulla is the middle region between the infundibulum and the isthmus. The isthmus is a short segment where the uterine tube connects to the uterine wall. The uterine tube is responsible for transporting the oocyte (before fertilization) and zygote (after fertilization) from the ovary to the uterine cavity. Additionally, it provides a nutrient-rich environment to nourish both spermatazoa and a developing pre-embryo (the cell cluster produced by the initial mitotic divisions following fertilization). Vaginal wall Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

Figure 28–19 The Uterine Wall. Here is another view of the layers of the uterus where you can see clear, structural differences. Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

[INSERT FIG ] Figure 28–22 The Female External Genitalia. Glands of clitoris The hymen is an elastic epithelial fold of variable size that partially blocks the entrance to the vagina. An intact hymen is typically stretched or torn during first sexual intercourse, tampon use, pelvic examination or physical activity. The vagina opens into the vestibule, the space bounded by the external genetalia. Small folds known as the labia minora surround the vestibule. Anterior to the urethral opening, the clitoris projects into the vestibule. The clitoris is derived from the same embryonic structures as the penis in males. Internally, it contains erectile tissue comparable to the corpa cavernosa of the penis; a small erectile glans sits atop it. These erectile tissues engorge with blood during sexual arousal. Extensions of the labia minora encircle the body of the clitoris, forming its prepuce. The mons pubis is a pad of adipose tissue covering the symphysis pubis. Adipose tissue also accumulates within the labia majora. Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

Figure 28–14 The Ovaries and Their Relationships to the Uterine Tube and Uterus. Blood vessels are connected to the ovary at the ovarian hilum, where the ovary attaches to the mesovarium. The visceral peritonium, or germinal epithelium, covering the surface of each ovary consists of a layer of columnar epithelial cells that overlies a dense connective tissue layer called the tunica albuginea. The interior tissues, or stroma, are divided into the superficial cortex and a deeper medulla. Gametes are produced in the cortex and are present in many different phases in the ovary. Shown here is the egg nest, mature follicle and corpus luteum. These structures will be discussed further in later slides. Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

Figure 28–15 Oogenesis. Ovum production, or oogenesis, begins before a woman’s birth, accelerates at puberty, and ends at menopause. Although the nuclear event in the ovaries during meiosis are the same as those in the testes, the process differs in two important details: 1. the cytoplasm of the primary oocyte is unevenly distributed during the two meiotic divisions. Oogenesis produces one secondary oocyte, which contains most of the original cytoplasm and two or three polar bodies, nonfunctional cells that later disintegrate; 2 the ovary releases a secondary oocyte rather than a mature ovum. The secondary oocyte is suspended in metaphase of meiosis II; meiosis will not be completed unless and until fertilization occurs. Female reproductive stem cells complete the mitotic production of primary oocytes before birth. These cells proceed as far as prophase of meiosis I, and remain in that state until the individual reaches puberty. Not all primary oocytes produced during fetal development survive until puberty. The ovaries have approximately 2 million primordial follicles at birth, each containing a primary oocyte. By puberty, the number has dropped to about 400,000. The rest of the primordial follicles degenerate in a process called atresia. Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

Primordial follicles in egg nest Figure 28–16 The Ovarian Cycle. Primary oocyte Follicle cells Primary oocytes are located in the outer portion of the ovarian cortex, near the tunica albuginea, in clusters called egg nests. A single squamous layer of follicle cells surrounds each primary oocyte within an egg nest. The primary oocyte and its follicle cells form a primordial follicle. Beginning at puberty, primordial follicles are continuously activated to join other follicles already in development. The activated primordial follicle will either mature and be released as a secondary oocyte or degenerate (atresia). This monthly process is known as the ovarian cycle. LM  1440 Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

Formation of primary follicle Figure 28–16 The Ovarian Cycle. Granulosa cells Primary oocytes Zona pellucida The preliminary steps in follicle development are of variable length but may take almost a year to complete. Follicle development begins with the activation of primordial follicles into primary follicles. The follicular cells enlarge, divide, and form several layers of cells around the growing primary oocyte. These follicle cells, which become rounded in appearance, are now called granulosa cells. Microvilli from the surrounding follicular cells intermingle with microvilli originating at the surface of the oocyte. This glycoprotein-rich region is called the zona pellucida. As the granulosa cells enlarge and multiply, adjacent cells in the ovarian stroma form a layer of theca cells around the follicle. Thecal cells and granulosa cells work together to produce sex hormones called estrogens. Thecal cells LM  1092 Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

Formation of secondary follicle Figure 28–16 The Ovarian Cycle. Thecal cells Zona pellucida Nucleus of primary oocyte Although many primordial follicles develop into primary follicles, only a few of the primary follicles mature further. The transformation begins as the wall of the follicle thickens and the deeper follicular cells begin secreting small amounts of fluid. This follicular fluid accumulates in small pockets that gradually expand to separate the inner and outer layers of the follicle. At this stage, the complex is known as the secondary follicle. Granulosa cells LM  1052 Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

Formation of tertiary follicle Figure 28–16 The Ovarian Cycle. Antrum containing follicular fluid Granulosa cells Corona radiata Eight to 10 days after the start of the ovarian cycle, the ovaries generally contain only a single secondary follicle destined for further development. By the 10th to 14th day of the cycle, that follicle has become a tertiary follicle, or mature graffian follicle, roughly 15mm in diameter. This complex spans the entire width of the ovarian cortex and distorts the ovarian capsule, creating a prominent bulge in the surface of the ovary. The oocyte procjects into the antrum, or expanded central chamber of the follicle which is surrounded by a mass of granulosa cells. On day 14 of a 28-day cycle, the secondary oocyte and the attached granulosa cells lose their connections with the follicular wall and drift free within the antrum. The granulosa cells still associated with the secondary oocyte form a protective layer known as the corona radiata. Secondary oocyte LM  136 Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

Released secondary oocyte
Primordial follicles Primary follicle Secondary follicle Tertiary follicle Released secondary oocyte Figure 28–16 The Ovarian Cycle. Corona radiata Corpus albicans Corpus luteum Ovulation At ovulation, the tertiary follicle releases the secondary oocyte. The distended follicular wall suddenly ruptures, ejecting the follicular contents, including the secondary oocyte and corona radiata into the pelvic cavity. The oocyte is then moved into the uterine tube by contact with the fimbriae that extend from its funnel-like opening, or by fluid currents produced by the cilia that line it. Follicular fluid Secondary oocyte within corona radiata Ruptured follicle wall Outer surface of ovary Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

Formation of corpus luteum Figure 28–16 The Ovarian Cycle. The empty tertiary follicle initially collapses, and ruptured vessels bleed into the antrum The remaining granulosa cells then invade the area, proliferating to create an endocrine structure known as the corpus luteum. The primary function of this structure is to produce the steroid hormone progesterone. LM  208 Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

Formation of corpus albicans Figure 28–16 The Ovarian Cycle. Degeneration of the corpus luteum begins about 12 days after ovulation (unless fertilization occurs). Progesterone and estrogen levels then fall markedly. Fibroblasts invade the nonfunctional corpus luteum, producing a knot of pale scar tissue called a corpus albicans. The disintegration, or involution, of the corpus luteum marks the end of the ovarian cycle. A new ovarian cycle then begins with the activation of another group of primordial follicles. LM  208 Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

Table 28-1 Hormones of the Reproductive System (female) Hormone Source Regulation of Secretion Primary Effects Gonadotropin-releasing homrome (GnRH) Hypothalamus GnRH pulse frequency incresed by estrogens, decreased by progestins Stimulates FSH and LH synthesis Follicle-stimulating hormone (FSH) Anterior lobe of the pituitary gland Stimulated by GnRH, inhibited by inhibin Stimulates follicle development, estrogen production, and oocyte maturation Lutinizing hormone (LH) Production stimulated by GnRH, secretion by the combination of high GnRH pulse frequencies and high estrogen levels Stimulates ovulation, formation of corpus luteum, and progestin secretion

Table 28-1 Hormones of the Reproductive System (female) Hormone Source Regulation of Secretion Primary Effects Estrogens (primarily estradiol) Granulosa and thecal cells of developing follices; corpus luteum Stimulated By FSH Stimulate LH secretion (at high levels); establish and maintain female secondary sex characteristics and sexual behavior; stimulate repair and growth of endometrium; increase frequency of GnRH pulses Progestins (primarily progesterone) Granulosa cells from midcycle through functional life of corpus luteum Stimulated by LH Stimulate endometrial growth and glandular secretion; reduce frequency of GnRH pulses Inhibin Granulosa cells of ovaries Stimulated by factors reseased by developing follicles Inhibits secretion of FSH (and possibly GnRH)

Sexual Function Female Sexual Arousal
Parasympathetic activation leads to Engorgement of erectile tissues Increased secretion of cervical mucous glands and greater vestibular glands Blood vessels in vaginal walls fill with blood Fluid moves from underlying connective tissues To vaginal surfaces Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

Sexual Function Female Orgasm Is accompanied by
Peristaltic contractions of uterine and vaginal walls Rhythmic contractions of bulbospongiosus and ischiocavernosus muscles Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

Figure 28–23a The Mammary Glands. Secretory Alveoli A newborn infant cannot fend for itself, and several of its key systems have not yet to complete development. Over the initial period of adjustment to an independent existence, the infant is nourished from the milk secreted by the maternal mammary glands. Milk production, or lactation occurs in these glands. On each side, a mammary gland lies in the subcutaneous tissue of the pectoral fat pad deep to the skin of the chest. Each breast has a nipple, a small conical projection where the ducts of the underlying mammary gland open onto the body surface. The reddish-brown skin around each nipple is the areola. The glandular tissue of a mammary gland consists of separate lobes, each containing several secretory lobules. Ducts leaving the lobules converge, giving rise to a single lactiferous duct in each lobe. Near the nipple, that lactiferous duct enlarges, forming an expanded chamber called a lactiferous sinus. Dense connective tissue surrounds the duct system and forms partitions that extend between the lobes and lobules. These bands of connective tissue, the suspensory ligaments of the breast, originate in the dermis of the overlying skin. The size of the mammary glands in a nonpregnant woman reflects primarily the amount of adipose tissue present, not the amount of glandular tissue. The secretory apparatus normally does not complete its development unless pregnancy occurs. Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

FOLLICULAR PHASE OF OVARIAN CYCLE LUTEAL PHASE OF OVARIAN CYCLE LH GnRH pulse frequency (pulses/day) Figure 28–26 The Hormonal Regulation of the Female Reproductive Cycle. Gonadotropic hormone levels (IU/L) FSH Follicle stages during the ovarian cycle Corpus luteum formation Mature corpus luteum Corpus albicans Ovulation Follicle development The female reproductive tract is under hormonal control that involves an interplay between secretions of both the pituitary gland and the gonads. *If these cycles are not properly coordinated, infertility results. Circulating levels of estrogens and progestins primarily control changes in GnRH pulse frequency from the hypothalamus. Estrogens increases the GnRH pulse frequency, and projestins decrease it. The endocrine cells of the anterior lobe of the pituitary gland, known as gonadotropes, respond as if each group is monitoring different frequencies. At one pulse frequency, the gonadotropes respond preferentially and secrete FSH, whereas at another frequency, LH is the primary hormone released. The ovarian cycle can be divided into a follicular phase, or preovulatory phase, and a luteal phase, or postovulatory phase. Ovulation marks the end of the follicular phase of the ovarian cycle and the start of the luteal phase. Early in the folicular phase of the ovarian cycle and prior to day 10, FSH is the dominant hormone released by the anterior lobe of the pituitary gland. The estrogens released by developing follicles inhibit LH secretion. As secondary follicles develop, FSH levels decline due to the negative feedback effects of inhibin. Follicular development and maturation continue, however, supported by the combination of estrogens, FSH and LH. As one or more tertiary follicles begin forming, the concentration of circulating estrogens rises steeply. As a result, LH secretion is stimulated and the effect of estrogen on LH secretion changes form inhibition to stimulation. The result is a massive release of LH from the anterior lobe of the pituitary gland triggering 1. the completion of meiosis I by the primary oocyte, 2. the forceful rupture of the follicular wall, and 3. ovulation. In the luteal phase, the high LH levels that trigger ovulation also promote progesterone secretion and the formation of the corpus luteum. As progesterone levels rise and estrogen levels fall, the LH secretion maintains the structure and secretory function of the corpus luteum. Although moderate amounts of estrogens are secreted by the corpus luteum, progesterone is the main hormone of the luteal phase. Progesterone Ovarian hormone levels Estrogens Inhibin DAYS Figure 28-25

FOLLICULAR PHASE OF OVARIAN CYCLE LUTEAL PHASE OF OVARIAN CYCLE Destruction of functional zone Repair and regeneration of functional zone Secretion by uterine glands Endometrial changes during the uterine cycle Phases of the uterine cycle MENSES PROLIFERATIVE PHASE SECRETORY PHASE The uterine cycle, or menstrual cycle, is a repeating series of changes in the structure of the endometrium. The uterine cycle averages 28 days in length, but it can range from 21 to 35 days in healthy women of reproductive age. Under the influence of estrogen and progesterone, the uterine glands, blood vessels and epithelium change with the phases of the monthy uterine cycle. We can divide the uterine cycle into three phases: 1. menses 2. the proliferative phase and 3. the secretory phase. Menses is marked by the degeneration of the functional zone of the endometrium. The sloughing off (shedding) of tissue in gradual in a process called menstruation, which generally lasts from one to seven days. In the days after menses, the epithelial cells of the uterine glands multiply and spread across the endometrial surface, resoring the uterine epithelium. Reorganization and growth of this functional zone is known as the proliferative phase. By the end of this phase, uterine glands are present, the uterine epithelium is essential “build back up” to where it was before menses and the tissue becomes highly vascularized. During the secretory phase of the uterine cycle, the uterine glands enlarge, accelerating their rates of secretion and the arteries that supply the uterine wall elongate and spiral through the tissues of the functional zone. The secretory phase lasts about 14 days and a new cycle begins with the onset of menses and disintegration of the functional zone. At the time of ovulation, the basal body temperature declines noticeably, making the rise in temperature over the following day even more noticeable. *Body temperature and LH levels in the blood can be used to predict ovulation when couples are looking to avoid or promote pregnancy. Basal body temperature (°C) DAYS Figure 28-25

If we compare the ovarian and uterine cycles, you can see that the follicular phase of the ovarian cycle and menses and the proliferative phase of the uterine cycle are occurring simultaneously, whereas the luteal phase of the ovarian cycle corresponds to the secretory phase of the uterine cycle. Restoration of the endometrium in the proliferative phase is occuring at the same time as the enlargement of the primary and secondary follicles in the ovary. The proliferative phase is stimulated and sustained by estrogens secreted by the developing ovarian follicles. The activity observed in the uterus during the secretory phase occurs under the combined stimulatory effects of progestins and estrogens from the corpus luteum whose main primary function is to continue the preparation of the uterus for pregnancy by enhancing the blood supply to the functional zone and stimulating secretion of uterine glands. The secretory phase begins at the time of ovulation and persists as long as the corpus luteum remains intact.

Fertilization, Pregnancy and Partuition

Fertilization Development begins at fertilization, or conception, when the male and female gametes fuse. We can divide development into stages characterized by specific anatomical changes. Embryological development comprises the events during the first two months after fertilization. The study of these events is called embryology. Fetal development begins at the start of the ninth week and continues until birth. Embryological and fetal development begins at the start of the ninth week and continues until birth. Embryological and fetal development are sometimes referred to collectively as prenatal development.

Fertilization Fertilization Capacitation
Occurs in uterine tube within a day after ovulation Secondary oocyte travels a few centimeters Spermatozoa must cover distance between vagina and ampulla Capacitation Must occur before spermatozoa can fertilize secondary oocyte Contact with secretions of seminal glands Exposure to conditions in female reproductive tract Fertilization involves the fusion of two haploid gametes, each containing 23 chromosomes, producing a zygote that contains 46 chromosomes, the normal complement in a somatic cell. After ovulation, oocytes are transported down the uterine tube by a combination of ciliary movement and peristaltic contractions in the walls of the uterine tube. It normally takes three to four days for an oocyte to travel from the infundibulum to the uterine cavity. If fertilization is to occur, the secondary oocyte must encounter spermatazoa during the first hours of its passage. (Unfertilized oocytes are broken down in the terminal portions of the uterine tubes or within the uterus without completing meiosis).

Fertilization Acrosomes Oocyte Activation
Release hyaluronidase and acrosin Penetrate corona radiata, zona pellucida, toward oocyte surface Oocyte Activation Contact and fusion of cell membranes of sperm and oocyte Follows fertilization Oocyte completes meiosis II, becomes mature ovum The acrosome of each sperm contains several enzymes, including hyaluronidase. Hyaluronidase breaks down the bonds between adjacent follicle cells. Dozens of spermatazoa must release hyaluronidase before the connections between follicle cells break down enough to allow an intact spermatazoon to reach the oocyte. The hyaluronidase and acrosin, another proteolytic enzyme, digest a path through the zona pellucida toward the surface of the oocyte. When the sperm contacts the surface of the oozyte, the sperm and oocyte membranes begin to fuse. This step is the trigger for oocyte activation, which involves a series of changes in the metabolic activity of the oocyte. This process is accompanied by the depolarization of the oocyte membrane due to an increased permeability to sodium ions. The entry of sodium ions in turn causes the release of calcium ions from the smooth endoplasmic reticulum. The sudden rise in Ca2+ levels has many important effects.

Fertilization Polyspermy Cortical Reaction
Fertilization by more than one sperm Prevented by cortical reaction Cortical Reaction Releases enzymes that: Inactivate sperm receptors Harden zona pellucida Prior to completion of the cortical reaction, depolarization of the oocyte membrane probably prevents fertilization by any sperm cells that penetrate the zona pellucida. Synthesis of proteins accelerates rapidly, especially those required for development to proceed.

Fertilization Female Pronucleus Male Pronucleus
Nuclear material remaining in ovum after oocyte activation Male Pronucleus Swollen nucleus of spermatozoon Migrates to center of cell

Fertilization Amphimixis
Fusion of female pronucleus and male pronucleus Moment of conception Cell becomes a zygote with 46 chromosomes Fertilization is complete *amphimixis means “both mixed together” At the moment of conception, the fertilized ovum is a single cell about .005 in in diameter and weighs approximately 150 µg.

Fertilization Cleavage Differentiation Series of cell divisions
Produces daughter cells Differentiation Involves changes in genetic activity of some cells but not others Cleavage is a series of cell divisions that produce an ever-increasing number of smaller and smaller daughter cells.

Figure 29-1b Fertilization
Oocyte at Ovulation Fertilization and Oocyte Activation Pronucleus Formation Begins Ovulation releases a secondary oocyte and the first polar body; both are surrounded by the corona radiata. The oocyte is suspended in metaphase of meiosis II. Acrosomal enzymes from multiple sperm create gaps in the corona radiata. A single sperm then makes contact with the oocyte membrane, and membrane fusion occurs, triggering oocyte activation and completion of meiosis. The sperm is absorbed into the cytoplasm, and the female pronucleus develops. Corona radiata First polar body Nucleus of fertilizing spermatozoon Female pronucleus Fertilizing spermatozoon Second polar body Zona pellucida Cleavage Begins Amphimixis Occurs and Cleavage Begins Spindle Formation and Cleavage Preparation The first cleavage division nears completion roughly 30 hours after fertilization. The male pronucleus develops, and spindle fibers appear in preparation for the first cleavage division. No matter how many spermatazoa slip through the gap in the corona radiata, only a single spermatazoon fertilizes and activates the oocyte 1. That spermatozoon must have an intact acrosome. The first step is the binding of the spermatozoon to sperm receptors in the zona pellucida, a thick envelope surrounding the oocyte. This binding triggers the rupture of the acrosome. 2. After oocyte activation and the completion of meiosis, the nuclear material remaining within the ovum reorganizes as the female pronucleus. While these changes are under way, the nucleus of the spermatazoon swells, and as it forms the male pronucleus the rest of the sperm cell breaks down. 3. The male pronucleus then migrates toward the center of the cell, and spindle fibers form. The two nuclei then fuse in a process called amphimixis. 4. The cell is now a zygote that contains the normal complement of 46 chromosomes, and fertilization is complete. This is the “moment of conception.” Almost immediately the chromosomes line up along the metaphase plate, and the cell prepares to divide. This is the start of cleavage. The first cleavage division is completed about 30 hours after fertilization, yielding two daughter cells, each one-half the size of the original zygote 5. The two daughter cells are called blastomeres. Metaphase of first cleavage division Male pronucleus Female pronucleus Blastomeres Fertilization and the preparations for cleavage. 50

Figure 29-2 Cleavage and Blastocyst Formation
Blastomeres Polar bodies 4-cell stage 2-cell stage Early morula DAY 1 DAY 2 DAY 3 Advanced morula DAY 4 First cleavage division Hatching DAY 0: Inner cell mass Fertilization Cleavage is a sequence of cell divisions that begins immediately after fertilization. During cleavage, the zygote becomes a pre-embryo, which develops into a multicellular complex known as a blastocyst. Cleavage ends when the blastocyst first contacts the uterine wall. After the first division is completed to form blastomeres, subsequent divisions occur at intervals of hours. During the initial divisions, all the blastomeres divide simultaneously. As the number of blastomeres increases, the timing becomes less predictable. After three days of cleavage, the pre-embryo is a solid ball of cells. This stage is called the morula and typically reaches the uterus on day 4. Over the next few days, the blastomeres form a blastocyst, a hollow ballwith an inner cavity known as the blastocoele. The outer layer of cells is called the trophoblast. The cells in this layer provide nutrients to the developing embryo. A second group of cells, the inner cell mass, lies clustered at one end of the blastocyst. These cells are exposed to the blastocoele but are insulated from contact with the outside environment by the trophoblast. In time, the inner cell mass will form the embryo. During blastocyst formation, enzymes released by the trophoblast erode an opening in the zona pellucida, which is then shed in a process known as hatching. When fully formed, the blastocyst contacts the endometrium and implantation occurs. DAY 6 Blastocoele Days 7–10: Implantation in uterine wall (See Figure 29–3) Trophoblast Blastocyst 51

Figure 29-3 Stages in Implantation (Part 1 of 2)
DAY 6 FUNCTIONAL ZONE OF ENDOMETRIUM UTERINE CAVITY Uterine glands Blastocyst DAY 7 Trophoblast Implantation begins with the attachment of the blastocyst to the endometrium of the uterus and continues as the blastocyst invades maternal tissues. Important events during implantation set the stage for the formation of vital embyronic structures. The surface of the blastocyst closest to the inner cell mass touches and adheres to the uterine lining. At the point of contact, the trophoblast cells divide rapidly, making the trophoblast serveral layers thick. The cells closest to the interior of the blastocyst remain intact, forming a layer of cellular trophoblast, or cytotrophoblast. Blastocoele Inner cell mass 52

Figure 29-3 Stages in Implantation (Part 2 of 2)
DAY 8 Cellular trophoblast Syncytial trophoblast DAY 9 Developing villi Near the endometrial wall, the plasma membranes separating the trophoblast cells disappear, creating a layer of cytoplasm containing multiple nuclei. This outer layer is called the syncytial trophoblast, or synctiotrophoblast. This layer of cells erodes a path through the uterine epithelium by secreting hyaluronidase. At first, the erosion creates a gap in the uterine lining, but migration and divisions of maternal epithelial cells soon repair the surface. By day 10 the repairs are complete, and the blastocyst has lost contact with the uterine cavity. Further development occurs entirely within the functional zone of the endometrium. As implantation proceeds, the syncytial trophoblast continues to enlarge and spread into the surrounding endometrium. The erosion of the uterine glands releases nutrients that are absorbed by the syncytial trophoblast and distrtibuted by diffusion through the underlying cellular trophoblast to the inner cell mass. These nutrients provide the energy needed to support the early stages of embryo formation. Trophoblastic extensions grow around endometrial capillaries. As the capillary walls are destroyed, maternal blood begins to percolate through trophoblastic channels known as lacunae. Fingerlike villi extend away from the trophoblast into the surrounding endometrium, gradually increasing in size and complexity. Amniotic cavity Lacuna 53

Figure 29-6a A Three-Dimensional View of Placental Structure
Decidua capsularis Umbilical cord (cut) Amnion Placenta Chorion Yolk sac Decidua basalis The germ layers are developed from the inner cell mass during a process called gastrulation. These layers are the outer ectoderm, middle mesoderm and inner endoderm and will eventually form all the organs and systems of the body. Germ layers also form four extraembryonic membranes:1. The yolk sac (endoderm and mesoderm) begins as a layer of cells spread out around the outer edges of the blastocoele to form a complete pouch, blood vessels soon appear within the mesoderm and the yolk sac becomes an important site of blood cell formation; 2. The amnion is composed of mesoderma and ectoderm as develoment proceeds, the amniotic cavity will enlarge, containing amniotic fluid, which surrounds and cushions the developing embryo or fetus; 3. The chorion is a combination of mesoderm and trophoblast cells, that will create a rapid-transit system for nutrients, forming blood vessels connecting the embryo with the trophoblast cells.pla The placenta is a complex organ that permits exchange between maternal and embryonic blood. Regional differences in placental organization begin to develop as expansion of the placenta creates a prominent bulge in the endometiral surface. This relatively thin portion of the endometrium, called the decidua capsularis no longer exchanges nutrients and the chorionic villi in the region disappear. In week 5 of pregnancy, placental funtions are concentrated in the deepest portion of the endometrium, a region called the decidua basalis. As the end of the first trimester approaches, the fetus moves farther from the placenta. The fetus and placenta remain connected by the umbilical cord. A view of the uterus after the fetus has been removed and the umbilical cord cut. 54

Figure 29-6a A Three-Dimensional View of Placental Structure
Chorionic villi Umbilical vein Umbilical arteries Area filled with maternal blood As the capillary walls of the endometrium are destroyed, blood from the maternal blood vessels begins to percolate through the lacunae. The appearance of blood vessels in the chorion is the first step in the creation of a functional placenta. By the third week of development, the mesoderm extends along the core of each trophoblastic villus, forming chorionic villi in contact with maternal tissues. These villi continue to enlarge and branch, creating an intricate network within the endometrium. Blood flows to the placenta through the paired umbilical arteries and returns in a single umbilical vein. The chorionic villi provide the surface area for active and passive exchanges of gases, nutrients, and waste products between the fetal and maternal bloodstreams. The blood in the umbilical arteries is deoxygenated and contains waste products generated by tissues. At the placenta, oxygen supplies are replenished, organic nutrients added and carbon dioxide and other organic waste products removed. Amnion Trophoblast (cellular and syncytial layers) Maternal blood vessels Arrows in the enlarged view indicate the direction of blood flow. 55

Gestation First Trimester Second Trimester Third Trimester
Period of embryological and early fetal development Rudiments of all major organ systems appear Second Trimester Development of organs and organ systems Body shape and proportions change Third Trimester Rapid fetal growth and deposition of adipose tissue Most major organ systems are fully functional The time spent in prenatal development is known as gestation. For convenience, we usually think of the gestation period as consisting of three integrated trimesters, each three months in duration. Many important and complex developmental events occur during the first trimester. By the end of the second trimester, the fetus looks distinctively human. An infant born one month or even two months prematurely has a reasonable chance of survival.

Figure 29-11 The Stages of Labor (Part 1 of 4)
Fully developed fetus before labor begins Pubic symphysis The goal of labor is partiution, the forcible expulsion of the fetus. During true labor, each contraction begins near the top of the uterus and sweeps in a wave toward the cervix. The contractions are strong and occur at regular intervals. As partuition approaches, the contractions increase in force and frequency, changing the position of the fetus and moving it toward the cervical canal. Labor is divided into three stages: the dilation stage, the expulsion stage and the placental stage Placenta Umbilical cord Sacral promontory Cervical canal Cervix Vagina 57

The Dilation Stage The dialation stage begins with the onset of true labor, as the cervix dilates and the fetus begins to shift toward the cervical canal, moved by gravity and uterine contractions. This stage is highly variable in length, but typically lasts eight or more hours. At the start of the dilation stage, labor contractions last up to half a minute and occur once every minutes; their frequency increases steadily. Late in this stage, the amniochorionic membrane ruptures, an event sometimes referred to as “having one’s water break.” If this event occurs before other events of the dilation stage, the life of the fetus may be at risk from infection. If the risk if sufficiently great, labor can be induced. 58

The Expulsion Stage The expulsion stage begins at the cervix, pushed open by the approaching fetus, completes its dilation to about 10 cm (4 in). In this stage, contractions reach maximum intensity, occurring at perhaps two- to three-minute intervals and lasting a full minute. Expulsion continues until the fetus has emerged from the vagina. In most cases, the expulsion stage lasts less than two hours. The arrival of the newborn infant to the outside world is delivery, or birth. If complications arise during the dilation stage or expulsion stage, the infant can be delivered by cesarean section, or “C-section.” In such cases, an incision is made through the abdominal wall, and the uterus is opened just enough to allow passage of the infant’s head. 59

The Placental Stage Uterus Ejection of the placenta During the placental stage of labor, muscle tension builds in the walls of the partially empty uterus, which gradually decreases in size. This uterine contraction tears the connections between the endometrium and the placenta. In general, within an hour of delivery, the placental stage ends with the ejection of the placenta, or afterbirth. The disruption of the placenta is accompanied by a loss of blood, but associated uterine contraction compresses the uterine vessels and usually restricts this flow. Because maternal blood volume has increased greatly during pregnancy, the blood loss that does occur can normally be tolerated without difficulty. 60

Sexual Function Impotence Also called male sexual dysfunction
Is an inability to achieve or maintain an erection Caused by physical or psychological factors The process of achieving an erection is complex and problems may occur for a variety of reasons, and could be psychological, physical, or a combination of the two. Physical causes are related to a breakdown or damage to the sequence of events that lead to an erection, including nerve impulses in the brain, spine, and penis as well as the subsequent response in the muscles, fibrous tissues, veins and arteries in and near the corpora cavernosa. Diseases that commonly cause impotence are diabetes, kidney disease, neurological disease, vascular disease and prostate cancer. The physical causes can also be surgery, injury, hormonal imbalances, venous leak tobacco, alcohol or drug use, perscription drugs and prostate enlargement. Ways to improve impotence include: adopting a healthier lifestyle, discontinuing use or reducing the dose of certain drugs, psychotherapy, medications or surgery. Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

Aging and the Reproductive System
Female reproductive system Changes associated with menopause Male reproductive system Changes associated with male climacteric (andropause) Occur gradually, over longer time period Menopause will be discussed further in the next slide. In the male climacteric (andropause), levels of circulating testosterone decline between years of age, and levels of circulating FSH and LH increase. Although sperm production continues (men well into their 80s can father children), older men experience a gradual reduction in sexual activity. This decrease may be linked to declining testosterone levels. Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

Aging and the Reproductive System
Menopause Is the time that ovulation and menstruation cease Typically occurs around age 45–55 Circulating concentrations of estrogens and progesterone decline Production of GnRH, FSH, and LH rises sharply At puberty, each ovary contains about 200,000 primordial follicles. Forty years later, few if any follicles remain, although only about 500 secondary oocytes will have been ovulated. By age 50, there are often no primordial follicles left to respond to FSH. The reduced estrogen concentrations have also been linked to the development of osteoporosis, cardiovascular disease and a variety of neural effects. Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

Sexual Function Sexually Transmitted Diseases (STDs)
Are transferred by sexual intercourse Include bacterial, viral, and fungal infections Pubic Lice AIDS Gonorrhea Syphilis Herpes Lice are tiny insects that live on humans and feed on blood. Pubic lice, also called crabs, are usually found in the pubic areas. Lice are spread easily from one person to another through close contact or through shared clothing or personal items. The most common symptoms of lice is itching. Pubic lice bites may cause small, flat, blue-gray marks that look like bruises on the torso, thighs, or upper arms. Treatment for pubic lice starts with removal of pubic lice and eggs with over-the-counter lotion or anti-lice shampoo followed by washing clothes, bedding or towels used and repeating treatment 9-10 days later. AIDS, or acquired immune deficiency syndrome, is caused by the HIV virus. The virus weakens a person’s ability to fight infections and cancer. It can take many years for AIDS to develop and is marked by certain infections or cancer or when a person’s CD4 count is less than Some people get flu-like symptoms a month or two after they have been infected with HIV, which often go away within a week to a month. A person can have HIV for many years before feeling ill. Signs that HIV is turning into AIDS include: a fever that won’t go away, sweating while you sleep, feeling tired all the time, feeling sick all the time, losing weight and swollen glands. There is no cure for AIDS, but once an infection is confirmed, a patient will be started on a drug regimen (HAART, highly-active anti-retroviral therapy). These drugs must be taken at the right time, ever single day and a range of side effects may occur including: diarrhea, nausea, or abnormal distribution of fat. If medications are taken incorrectly or inconsistently, the virus can mutate, or change, into a strain resistant to treatment. Gonorrhea is caused by Neisseria gonorrhoeae, a bacterium that can grow and multiply easily in mucus membranes of the body. Gonorrhea bacteria can grow in the warm, moist areas of the reproductive tract including the cervix, uterus, and fallopian tubes in women and in the urethra in women and men. The bacteria can also grow in the mouth, throat, and anus. Symptoms include: greenish yellow or whitish discharge from the vagina, lower abdominal or pelvic pain, burning when urinating, conjunctivitis, bleeding between periods, spotting after intercourse, swelling of the vulva, painful or swollen testicles, burning in the throat and swollen glands in the throat (in some women, symptoms are so mild they can escaped unnoticed). Gonorrhea can be treated and cured with either an oral or injectable antibiotic. Syphilis is caused by the bacteria Treponema pallidum. Syphilis infection occurs in three distinct stages: in early or primary syphilis people will develop one or more sores that resemble large round bug bites and are often hard and painless, occurring in the genitals or in or around the mouth; the secondary stage may last one to three months and people will experience a rosy “copper penny” rash typically on the palms of the hands and feet; latent syphilis is where the infection lies dormant without causing symptoms; tertiary syphilis is characterized by severe problems with the heart, brain and nerves that can result in paralysis, blindness, dementia, deafness, impotence and even death if its not treated. If a person is infected with syphilis for less than a year, a single dose of penicillin is usually enough to destroy the infection. Later stages of syphilis require more doses. Genital herpes is caused by the herpes simplex virus-2 (HSV-2) although herpes simplex virus-1 (HSV-1), the virus usually responsible for cold sores, may cause genital herpes. It is highly contagious and is spread through intercourse with a person with infected sores. Most people infected with genital herpes have very minimal or no signs or symptoms of the disease. The first attack of herpes usually follows this course: skin on or near the sex organ becomes inflamed, skin may burn, itch or be painful, blister-like sores appear on or near the sex organs, sores open, scab over, and then heal. Symptoms that may also be present when the virus first appears include: swollen glands, fever, headache, burning when passing urine and muscle aches. The first outbreak of herpes can last for several weeks. After the outbreak, the virus retreats to the nervous system, where it remains inactive until something triggers it to become active again. Triggers can include stress, illness, surgery, vigorous sex, diet and monthly period. There is no cure for genital herpes, but anti-viral drugs, in pill or ointment form may help the sores heal faster. If reoccurrence is frequent, an antiviral medication may be prescribed. Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Pubic lice

Sexual Function Sexually Transmitted Diseases (STDs) (cont’d)
Genital warts Chancroid Hepatitis Clamydia Trichomaniasis Genital warts are caused by the human papillomavirus (HPV) which can be spread through skin-to-skin contact. Genital warts are skin growths in the groin, genital or anal areas. They can be different sizes and shapes and sometimes you can’t see the warts at all. Most people infected with HPV don’t have symptoms, but if they do symptoms can include pain, itching, and bleeding, or development of visible genital warts. There is no cure for HPV, but the symptoms can be treated. Treatment of genital warts include prescription medications or removal with lasers, surgery, or by freezing them off. Chancroid is caused by a bacteria called Haemophilus ducreyi. It is found mainly in developing and third world countries, only a small number of cases are diagnosed in the U.S. each year. Within 1 day – 2 weeks after getting chancroid, a person will get a small bump in the genitals. The bump becomes an ulcer within a day of its appearance and ranges in size from 1/8 in. to 2 in. across, is painful, soft, has sharply defined borders, has a base that is covered with a grey or yellowish-grey material and has a base that bleeds easily if it is banged or scraped. These ulcers may look like those caused by primary syphilis. Some people may also develop swollen lymph nodes that may break through the skin and cause draining abscesses. The infection is treated with antibiotics and if necessary, large lymph node swellings need to be drained, either with a needle or local surgery. Hepatitis is swelling and inflammation of the liver and can be caused by immune cells in the body attacking the liver and causing autoimmune hepatitis, infections from viruses (such as hepatitis A, B or C), bacteria or parasites, liver damage from alcohol, poisonous mushrooms or other poisons, medications such as an overdose of acetaminophen which can be deadly. Hepatitis may start and get better quickly (acute hepatitis), or cause long-term disease (chronic hepatitis). In some instances it may lead to liver damage, liver failure, or even liver cancers. The symptoms of hepatitis include: abdominal pain or distention, breast development in males, dark urine and pale or clay-colored stools, fatigue, fever (usually low grade), general itching, jaundice, loss of appetite, nausea and vomiting and weight loss. Possible treatments depend on the cause of liver disease, but discontinuing use of substances causing the disease or medications can be used to stop or slow down further damage to the liver. If the liver is too damaged to function, a transplant may be necessary. Clamydia is one of the most common sexually transmitted diseases in the U.S. This infection is easily spread because it often causes no symptoms and may be unknowing passed to sexual partners. It is caused by the bacteria Chlamydia trachomatis. Chlamydia symptoms in women include: abnormal vaginal discharge that may have an odor, bleeding between periods, painful periods, abdominal pain with fever, pain when having sex, itching or burning in or around the vagina and pain when urinating. Chlamydia symptoms in men include: small amounts of clear or cloudy discharge from the tip of the penis, painful urination, burning and itching around the opening of the penis and pain and swelling around the testicles. Clamydia can be treated with oral antibiotics. Trichomaniasis is caused by the parasite Trichomonas vaginalis. This parasite is spread through sexual contact with an infected partner, but cannot survive in the mouth or rectum. Symptoms in women include: discomfort, itching of the inner thighs, vaginal discharge (thin, greenish-yellow, frothy or foamy), vaginal itching, vulvar itching or swelling of the labia and vaginal odor. Symptoms in men include: buring after urination or ejaculation, itching of the urethra and slight discharge from the urethra. Antibiotics are commonly used to cure the infection. Hepatitis (B)

Diseases of the Reproductive System
Amenorrhea Breast Cancer Cervical Cancer Prostate Cancer Vaginitis If menarche doesn’t appear by age 16, or if the normal uterine cycle of an adult woman becomes interrupted for six months or more, the condision of amenorrhea exists. Primary amenhorrea is the failure to initiate menses. This condition may indicated developmental abormalities, such as nonfunctional ovaries, the absence of a uterus or an endocrine or genetic disorder. It can also result from malnutrition (puberty is delayed if leptin levels are too low). Transient secondary amenorrhea can be caused by severe physical or emotional stresses. In effect, the reproductive system gets “switched off.” Factors associated with amenorrhea include drastic weight loss, anorexia nervosa, and severe depression or grief. There is no treatment for primary amenorrhea, but removal or treatment of stresses can result in return or normal cycles over time. Breast cancer occurs when abnormal cells of the breast grow out of control. Although the precise causes of breast cancer are unclear, we know the main risk factors. Among the most significant of these are advancing age and a family history of breast cancer. In its early stages, breast cancer usually has no symptoms. As a tumor develops, the following signs can develop: a lump in the breast, swelling in the armpit, pain or tenderness of the breast, changes in size, contour, texture or temperature, changes in the nipple and unusual discharge from the nipple. Breast cancer treatments can be local (in the general vicinity of the tumor) or systemic (in the whole body). Local treatments are used to remove, destroy or control the cancer cells including surgery or radiation therapy. Systemic treatments include: chemotherapy, hormone therapy and biological therapy. Cervical cancer occurs when abnormal cells on the cervix grow out of control. The cervix is the lower part of the uterus that opens into the vagina. Cervical cancer can often be cured when it’s found early. It is usually found at a very early stage through a pap test. Most cervical cancer is caused by certain types of a virus called human papillomavirus or HPV. Abnormal cervical cell changes rarely cause symptoms. If these cells grow into cervical cancer symptoms that can result are: bleeding from the vagina that is not normal, or an abnormal change in the menstrual cycle, bleeding when something comes in contact with your cervix, such as during sex or diaphragm insertion, pain during sex and vaginal discharge that is tinged with blood. The treatment for most stages of cervical cancer removes the cancer and may lead to infertility. Treatments include: a hysterectomy and removal of pelvic lymph nodes with or without removal of both ovaries and fallopian tubes, radiation therapy and chemotherapy. Prostate cancer cells don’t follow normal patterns and grow uncontrollably and spread to other tissues. Prostate cancer is typically a very slow growing tumor, often causing no symptoms until advanced stages. Once prostate cancer begins to grow more rapidly or spreads outside the prostate, it is dangerous and generally fatal. High testosterone levels may stimulate dormant prostate cells into activity. Other risk factors for prostate cancer include low physical activity and smoking. There are no early warning signs or symptoms of prostate cancer. Once a malignant tumor causes the prostate gland to swell significantly, or once cancer spreads beyond the prostate, the following symptoms may be present: a frequent need to urinate, especially at night, difficulty starting or stopping a stream of urine, a weak or interrupted urinary stream, inability to urinate standing up, a painful or burning sensation during urination or ejaculation and blood or urine in semen. Prostate cancer treatment options are surgery, radiation therapy and hormonal therapy (androgen deprivation). Vaginitis is a medical term used to describe various conditions that cause infection or inflammation of the vagina. These conditions can result from a vaginal infection caused by organisms such as bacteria, yeast, or viruses, as well as by irritations from chemicals in creams, sprays, or even clothing that is in contact with this area. In some cases, vaginitis results from organisms that are passed between sexual partners. The symptoms of a vaginal infection can vary depending on what is causing it. Some women have no symptoms at all. Some of the more common symptoms of vaginitis include: abnomral vaginal discharge with an unpleasant odor, burning during urination, itching around the outside of the vagina and discomfort during intercourse. Treatments for vaginitis depend on what is causing it. Bacterial infections can be treated with a cream suppository medicine inserted directly into the vagina or a pill form taken orally. Irritations from allergic reactions can be treated by discontinuing use of these items.

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