CHAPTER 27 The Reproductive System © 2011 T he McGraw -Hill Com panie s, Inc A ll rights reserv ed 27-2 Learning Outcomes 27.1 List the organs of the male reproductive system and give the locations, structures, and functions of each 27.2 Describe how sperm cells are formed 27.3 Describe the substances found in semen 27.4 Describe the process of erection and ejaculation © 2011 T he McGraw -Hill Com panie s, Inc A ll rights reserv ed 27-3 Learning Outcomes (cont.) 27.5 List the actions of testosterone 27.6 Describe the causes, signs and symptoms, and treatment of various disorders of the male reproductive system 27.7 List the organs of the female reproductive system and give the locations, structures, and functions of each 27.8 Explain how ova develop © 2011 T he McGraw -Hill Com panie s, Inc A ll rights reserv ed 27-4 Learning Outcomes (cont.) 27.9 List the actions of estrogen and progesterone 27.10 Explain how and when ovulation occurs 27.11 Describe what happens to an ovum after ovulation occurs 27.12 List the purpose and events of the menstrual cycle 27.13 Define menopause and explain what causes it © 2011 T he McGraw -Hill Com panie s, Inc A ll rights reserv ed 27-5 Learning Outcomes (cont.) 27.14 Describe the causes, signs and symptoms, and treatments of various disorders of the female reproductive system 27.15 Explain how and where fertilization occurs 27.16 Describe the process of implantation 27.17 Explain the difference between an embryo and a fetus © 2011 T he McGraw -Hill Com panie s, Inc A ll rights reserv ed 27-6 Learning Outcomes (cont.) 27.18 Describe the changes that occur in a woman during pregnancy 27.19 List several birth control methods and explain why they are effective 27.20 List the causes of and treatments for infertility 27.21 Describe the causes, signs and symptoms, and treatments of the most common sexually transmitted diseases © 2011 T he McGraw -Hill Com panie s, Inc A ll rights reserv ed 27-7 Introduction • Male and female reproductive systems – Function together to produce offspring – Female reproductive system nurtures developing offspring – Produce important hormones © 2011 T he McGraw -Hill Com panie s, Inc A ll rights reserv ed 27-8 Male Reproductive System • Testes – Primary organs • Develop in the abdominal pelvic cavity of fetus • Scrotum – sac that holds the testes • Seminiferous tubules – On top of testes • Descend into scrotal sac shortly before or after birth – Produce the male sex cells (sperm) – Produce the male hormone testosterone – Filled with spermatogenic cells that produce sperm cells • Interstitial cells produce testosterone Male System © 2011 T he McGraw -Hill Com panie s, Inc A ll rights reserv ed 27-10 Spermatogenesis Spermatogenesis Spermatogonia (46 chromosomes) Mitosis – makes primary spermatocytes Undergo meiosis two secondary spermatocytes Divides – two spermatids = spermatids Develop flagella to become mature sperm cells with 23 chromosomes © 2011 T he McGraw -Hill Com panie s, Inc A ll rights reserv ed 27-11 Sperm Cells • Head – Nucleus with 23 chromosomes – Acrosome – enzymefilled sac • Tail – Flagellum that propels sperm forward • Helps sperm penetrate ovum • Midpiece – Mitochrondria that generate cell’s energy © 2011 T he McGraw -Hill Com panie s, Inc A ll rights reserv ed 27-59 Infertility (cont.) • Tests – Semen analysis – Monitoring of morning body temperature – Blood hormone measurements – Endometrial biopsy – Urine analysis for LH – Hysterosalpingogra m – Laparoscopy • Treatments – Surgical repair of abnormalities – Fertility drugs – Hormone therapies – Artificial insemination – In vitro fertilization – Use of surrogate © 2011 T he McGraw -Hill Com panie s, Inc A ll rights reserv ed 27-60 Apply Your Knowledge Indicate whether each cause of infertility is male-related (M), female-related (F), or both (B) ANSWER: M Retrograde ejaculation _ M Mumps infection _ F Inadequate diet _ B Scarring from STDs _ F _ Pelvic inflammatory disease F _ Hormone imbalances M _ Use of some medications F _ Being over 40 years old Very © 2011 T he McGraw -Hill Com panie s, Inc A ll rights reserv ed 27-61 Sexually Transmitted Diseases STD Cause AIDS HIV virus causes AIDS; described in Chapter 21 Chlamydia Caused by bacterium; most commonly reported; often no symptoms in female Genital warts Caused by HPV; not everyone infected has symptoms Gonorrhea Bacterial cause © 2011 T he McGraw -Hill Com panie s, Inc A ll rights reserv ed 27-62 Sexually Transmitted Diseases (cont.) STD Cause Herpes simplex Caused by viruses; type I causes cold sores; type II commonly known as genital herpes; may be passed from mother to child during childbirth Pubic lice Parasitic infestation; commonly called crabs Syphilis Caused by bacteria; decreasing in women but increasing in males who have sex with other males Trichomoniasis Caused by protozoan parasite; also called trichomonas infection or “trich” © 2011 T he McGraw -Hill Com panie s, Inc A ll rights reserv ed 27-63 Apply Your Knowledge Match: ANSWER: D Most commonly reported STD in the U.S _ A F Two types; both caused by a virus _ B E Crabs _ C C Increasing incidence in males _ D A Common bacterial STD; can also grow in mouth E _ B Caused by HPV virus _ S Gonorrhea U Genital warts P Syphilis E Chlamydia R Pubic lice ! F Herpes simplex © 2011 T he McGraw -Hill Com panie s, Inc A ll rights reserv ed 27-64 In Summary 27.1 The organs of the male reproductive system include the testes, responsible for sperm and hormone production, and the accessory organs of vas deferens, seminal vesicles, prostate and bulbourethral glands, scrotum, and penis 27.2 Spermatogenesis begins in the seminiferous tubules of the testes They mature in the epididymis first as spermatogonia, then as spermatocytes, and finally as spermatids © 2011 T he McGraw -Hill Com panie s, Inc A ll rights reserv ed 27-65 In Summary (cont.) 27.3 Semen is a mixture of seminal fluid, prostatic fluid, sperm cells, and lubricating bulbourethral fluid 27.4 Erection occurs during sexual arousal, causing penile engorgement with blood Ejaculation occurs when semen and its sperm cells are forced out of the body through the urethra 27.5 Testosterone is responsible for the male secondary sex characteristics and maturation of the male reproductive organs © 2011 T he McGraw -Hill Com panie s, Inc A ll rights reserv ed 27-66 In Summary (cont.) 27.6 The diseases of the male reproductive system vary widely between simple inflammation and cancers The more common diseases and disorders, with their varied symptoms and treatments, are outlined in the Pathophysiology section of this chapter, immediately following the A&P of the male reproductive system 27.7 The organs of the female reproductive system include the ovaries, fallopian tubes, uterus, and vagina The external accessory organs include the mons pubis, labia majora and minora, clitoris, urethral meatus, vaginal orifice, Bartholin’s glands, perineum, and mammary glands © 2011 T he McGraw -Hill Com panie s, Inc A ll rights reserv ed 27-67 In Summary (cont.) 27.8 Ova originate from the primordial follicles within the ovaries present during fetal development, which produce the oocyte and follicular cells responsible for oogenesis 27.9 Estrogen is responsible for female secondary sex characteristics Both estrogen and progesterone stimulate the uterine lining to thicken in preparation for pregnancy and inhibit uterine contractions during pregnancy 27.10 Ovulation occurs when the anterior pituitary releases a surge of LH, causing the release of a mature ovum © 2011 T he McGraw -Hill Com panie s, Inc A ll rights reserv ed 27-68 In Summary (cont.) 27.11 The follicular cells become the corpus luteum, which releases more progesterone, which causes the uterine lining to become more vascular and glandular to prepare for the pregnancy 27.12 The female menstrual cycle causes periodic changes in the uterine lining After a menstrual period, the body prepares for the next ovulatory cycle with increasing levels of estrogen and progesterone If pregnancy does not occur, these levels drop, causing the uterine lining to break down and resulting in the next menstrual period © 2011 T he McGraw -Hill Com panie s, Inc A ll rights reserv ed 27-69 In Summary (cont.) 27.13 Menopause is the cessation of the menstrual cycle related to normal aging of the ovaries 27.14 The diseases of the female reproductive system vary widely between simple inflammation and cancers The more common diseases and disorders, with their varied symptoms and treatments, are outlined in the Pathophysiology section of this chapter, immediately following the A&P of the female reproductive system © 2011 T he McGraw -Hill Com panie s, Inc A ll rights reserv ed 27-70 In Summary (cont.) 27.15 Fertilization occurs with the union of a sperm cell and ovum; usually occurs within the fallopian tubes, but may occur anywhere in the female reproductive tract 27.16 The fertilized ovum, now a blastocyst, implants in the endometrial wall of the uterus 27.17 The embryonic period occurs from week 2−8 of the pregnancy, and the fetal period is from week through delivery © 2011 T he McGraw -Hill Com panie s, Inc A ll rights reserv ed 27-71 In Summary (cont.) 27.18 Hormonal changes stimulate the uterine lining and inhibit FSH and LH production to prevent ovulation Mammary glands are stimulated and enlarged, uterine contractions are inhibited, and the pelvic ligaments loosen in preparation for delivery 27.19 Some of the contraceptive methods include coitus interruptus; barrier methods; chemical barriers; oral contraceptives; injectable, implantable and insertable contraceptives; and intrauterine devices Their mechanisms are discussed in detail within the chapter © 2011 T he McGraw -Hill Com panie s, Inc A ll rights reserv ed 27-72 In Summary (cont.) 27.20 The causes of infertility are varied, with about 15% of infertility for unknown causes A number of infertility tests and treatments are discussed within the chapter 27.21 There are many sexually transmitted diseases, all passed between sexual partners (heterosexual and same-sex partners alike) Their symptoms, treatments, and sequelae for both sexes are discussed in detail in the Pathophysiology section devoted to STDs at the end of this chapter © 2011 T he McGraw -Hill Com panie s, Inc A ll rights reserv ed 27-73 End of Chapter 27 The reproduction of mankind is a great marvel and mystery ~Martin Luther © 2011 T he McGraw -Hill Com panie s, Inc A ll rights reserv ed [...]... • Uterus – Hollow, muscular organ – Receives embryo and sustains its development – Divisions • Fundus – domed upper portion • Body – main portion • Cervix – narrow, lower section extending into vagina (cervical orifice) Internal Accessory Organs – Wall of uterus • Endometrium – Innermost lining – Vascular – Tubular glands – mucus • Myometrium – Middle, thick, muscular layer • Perimetrium – Thin layer... s, Inc A ll rights reserv ed 27- 28 Internal Female Organs Back © 2011 T he McGraw -Hill Com panie s, Inc A ll rights reserv ed 27- 29 External Accessory Organs • Mammary glands – Secretion of milk – Structures • Nipple – Oxytocin induces lactiferous ducts to deliver milk through openings • Areola – pigmented area around nipple • Alveolar glands – within mammary glands – Make milk when stimulated by... myometrium – Secretes serous fluid to coat and protect uterus © 2011 T he McGraw -Hill Com panie s, Inc A ll rights reserv ed 27- 27 Female Internal Accessory Organs (cont.) • Vagina – Tubular, muscular organ – Extends from uterus to outside body (vaginal introitus) – Muscular folds – rugae – enable expansion • Receive erect penis • Passage for delivery of offspring and uterine secretions – Wall • Innermost... • Prostoglandins – 1.5 to 5.0 ml per ejaculate – Sperm count of 40 to 250 million/mL Male System © 2011 T he McGraw -Hill Com panie s, Inc A ll rights reserv ed 27- 15 Male External Accessory Organs • Scrotum – Holds testes away from body • Penis – Shaft • Erectile tissues surround urethra – Temperature 1° below body temperature – Glans penis – Lined with serous membrane that secrets fluid – Prepuce... ed 27- 31 External Genitalia (cont.) • Clitoris – Anterior to urethral meatus – Contains female erectile tissue – Rich in sensory nerves • Perineum – Between vagina and anus – Area for episiotomy, if needed, during birth process External Genitalia © 2011 T he McGraw -Hill Com panie s, Inc A ll rights reserv ed 27- 32 Erection, Lubrication, and Orgasm • Nervous stimulation – Clitoris becomes erect – Bartholin’s... rights reserv ed 27- 14 Male Internal Accessory Organs (cont.) • Prostate gland – Surrounds urethra – Produces and secretes a milky, alkaline fluid into urethra just before ejaculation – Fluid protects sperm in the acidic environment of the vagina – 40% of semen • Bulbourethral (Cowper’s) glands – Produce a mucus-like fluid • Secreted just before ejaculation • Lubricates end of penis • Semen – Alkaline mixture... Com panie s, Inc A ll rights reserv ed 27- 30 External Genitalia • Collectively known as the vulva • Labia majora – Rounded folds of adipose tissue and skin – Protect other external reproductive organs • Labia minora – – – – Folds of skin between labia majora Very vascular Merge to form hood over clitoris Vestibule – space enclosed by labia minora • Bartholin’s glands secrete mucus during sexual arousal.. .27- 13 Male Internal Accessory Organs • Seminal vesicle • Epididymis – Sits on top of each testis – Receives spermatids from seminiferous tubules – Spermatids become sperm cells • Vas deferens – Tube connected to epididymis – Carries sperm cells to urethra – Secrete • Fluid rich in sugar used to make energy • Prostaglandins – stimulate muscular contractions in female to propel sperm forward – Seminal... Inc A ll rights reserv ed 27- 25 Female Internal Accessory Organs • Fallopian tube – oviduct – Infundibulum and fimbriae • Fringed, expanded end of fallopian tube near ovary • Function to “catch” an ovum – Muscular tube • Lined with mucous membrane and cilia • Propels ovum toward uterus Internal Accessory Organs © 2011 T he McGraw -Hill Com panie s, Inc A ll rights reserv ed 27- 26 Female Internal Accessory... males – Functions • Deliver sperm • Urination Male System © 2011 T he McGraw -Hill Com panie s, Inc A ll rights reserv ed 27- 16 Erection, Orgasm, and Ejaculation • Erection – Parasympathetic nervous system stimulates erectile tissue – Becomes engorged with blood • Orgasm – Sperm cells propelled out of testes into urethra – Secretions from accessory organs also released into urethra • Ejaculation – Semen