1. Chapter 20 The Reproductive Systems Jeanelle F. Jimenez RN, BSN, CCRN

2. COMMON STRUCTURAL AND FUNCTIONAL CHARACTERISTICS BETWEEN THE SEXES
Common general structure and function can be identified between the systems in both sexes
Systems adapted for development of sperm or ova followed by successful fertilization, development, and birth of offspring
Sex hormones in both genders important in development of secondary sexual characteristics and normal reproductive system activity

3. MALE REPRODUCTIVE SYSTEM
Structural plan—organs classified as essential or accessory
Essential organs of reproduction are the gonads (testes), which produce sex cells (sperm or spermatozoa)
Accessory organs of reproduction
Ducts—passageways that carry sperm from testes to exterior
Sex glands—produce protective and nutrient solution for sperm
External genitals

4. MALE REPRODUCTIVE SYSTEM
Testes—the gonads of men
Structure and location (Figure 20-2 p 494)
Testes in scrotum—lower temperature
Covered by tunica albuginea, which divides testis into lobules containing seminiferous tubules
Interstitial cells (located near the septa that separate the lobules fig 20-3 page 494) produce testosterone .

6. MALE REPRODUCTIVE SYSTEM
Testes (cont.)
Functions
Spermatogenesis is process of sperm production (Figure 20-4)
Sperm precursor cells called spermatogonia
Meiosis produces primary spermatocyte, which forms four spermatids with 23 chromosomes
Spermatozoa—highly specialized cells
Head contains genetic material
Acrosome contains enzymes to assist sperm in penetration of ovum
Mitochondria in midpiece provide energy for movement
Production of testosterone by interstitial cells
Testosterone “masculinizes” and promotes development of male accessory organs
Promotes and maintains development of male accessory organs
Stimulates protein anabolism and development of muscle strength

7. MALE REPRODUCTIVE SYSTEM
Reproductive ducts—ducts through which sperm pass after exiting testes until they exit from the body
Epididymis—single, coiled tube about 6 m in length; lies along the top and behind the testis in the scrotum
Sperm mature and develop the capacity for motility as they pass through epididymis
Ductus (vas) deferens—receives sperm from the epididymis and transports them from scrotal sac through the abdominal cavity
Passes through inguinal canal
Joins duct of seminal vesicle to form the ejaculatory duct

8. MALE REPRODUCTIVE SYSTEM
Accessory, or supportive, sex glands—semen: mixture of sperm and secretions of accessory sex glands; averages 3 to 5 mL per ejaculation, with each milliliter containing about 100 million sperm
Seminal vesicles
Pouchlike glands that produce about 60% of seminal fluid volume
Secretion is yellowish, thick, and rich in fructose to provide energy needed by sperm for motility
Prostate gland
Shaped like a doughnut and located below bladder
Urethra passes through the gland
Secretion represents 30% of seminal fluid volume—is thin and milk-colored
Activates sperm and is needed for ongoing sperm motility
Bulbourethral (Cowper’s) glands
Resemble peas in size and shape
Secrete mucus-like fluid constituting less than 5% of seminal fluid volume

9. MALE REPRODUCTIVE SYSTEM
External genitals
Penis and scrotum called genitalia
Penis has three columns of erectile tissue—two dorsal columns called corpora cavernosa and one ventral column surrounding urethra called corpus spongiosum
Glans penis covered by foreskin (prepuce)
Surgical removal of foreskin called circumcision

10. FEMALE REPRODUCTIVE SYSTEM
Structural plan—organs classified as essential or accessory
Essential organs are gonads (ovaries), which produce sex cells (ova)
Accessory organs of reproduction
Ducts or modified ducts—including oviducts, uterus, and vagina
Sex glands—including the breasts
External genitals

11. FEMALE REPRODUCTIVE SYSTEM
Ovaries
Structure and location
Paired glands weighing about 3 g each
Resemble large almonds
Attached to ligaments in pelvic cavity on each side of uterus
Microscopic structure (Figure 20-8)
Ovarian follicles—contain an oocyte, which is an immature sex cell (about 1 million at birth)
Primary follicles—about 400,000 at puberty are covered with granulosa cells
About 350 to 500 mature follicles ovulate during the reproductive lifetime of most women—sometimes called graafian follicles
Secondary follicles have a hollow chamber called the antrum
Corpus luteum forms after ovulation

13. FEMALE REPRODUCTIVE SYSTEM
Ovaries (cont.)
Functions
Oogenesis—this meiotic cell division produces daughter cells with equal chromosome numbers (23) but unequal cytoplasm; ovum is large; polar bodies are small and degenerate
Production of estrogen and progesterone
Granulosa cells surrounding the oocyte in the mature and growing follicles produce estrogen
Corpus luteum produces progesterone
Estrogen causes development and maintenance of secondary sex characteristics
Progesterone stimulates secretory activity of uterine epithelium and assists estrogen in initiating menses

14. FEMALE REPRODUCTIVE SYSTEM
Reproductive ducts
Uterine (fallopian) tubes (oviducts)
Extend about 10 cm from uterus into abdominal cavity
Expanded distal end surrounded by fimbriae
Mucosal lining of tube is directly continuous with lining of abdominal cavity
Uterus—composed of body, fundus, and cervix (Figure 20-9)
Lies in pelvic cavity just behind urinary bladder
Myometrium is muscle layer
Endometrium lost in menstruation
Menopause—end of repetitive menstrual cycles (about years of age)
Vagina
Distensible tube about 10 cm long
Located between urinary bladder and rectum in the pelvis
Receives penis during sexual intercourse and is birth canal for normal delivery of baby at end of term of pregnancy
Accessory or supportive sex glands

16. FEMALE REPRODUCTIVE SYSTEM
Accessory, or supportive, sex glands
Bartholin’s (greater vestibular) glands
Secrete mucus-like lubricating fluid
Ducts open between labia minora
Breasts (Figure 20-10)
Located over pectoral muscles of thorax
Size determined by fat quantity more than amount of glandular (milk-secreting) tissue
Lactiferous ducts drain at nipple, which is surrounded by pigmented areola
Lymphatic drainage important in spread of cancer cells to other body areas

18. FEMALE REPRODUCTIVE SYSTEM
External genitals (Figure 20-11)
Vulva includes mons pubis, clitoris, orifice of urethra, Bartholin’s gland, vagina, labia minora and majora, and hymen
Perineum—area between vaginal opening and anus
Surgical cut during childbirth called episiotomy

20. FEMALE REPRODUCTIVE SYSTEM
Menstrual cycle—involves many changes in the uterus, ovaries, vagina, and breasts (Figures and 20-13)
Length—about 28 days, varies from month to month among individuals and in the same individual
Phases
Menses—about the first 4 or 5 days of the cycle, varies somewhat; characterized by sloughing of bits of endometrium (uterine lining) with bleeding
Proliferative phase—days between the end of menses and secretory phase; varies in length; the shorter the cycle, the shorter the proliferative phase; the longer the cycle, the longer the proliferative phase
Secretory phase—days between ovulation and beginning of next menses; secretory about 14 days before next menses; characterized by further thickening of endometrium and secretion by its glands in preparation for implantation of fertilized ovum; combined actions of the anterior pituitary hormones FSH and LH cause ovulation; sudden sharp decrease in estrogens and progesterone bring on menstruation if pregnancy does not occur

23. SUMMARY OF MALE AND FEMALE REPRODUCTIVE SYSTEMS
In men and women the organs of the reproductive system are adapted for the specific sequence of functions that permit development of sperm or ova after the successful fertilization and then the normal development and birth of offspring
The male organs produce, store, and ultimately introduce mature sperm into the female reproductive tract

24. SUMMARY OF MALE AND FEMALE REPRODUCTIVE SYSTEMS
The female system produces ova, receives the sperm, and permits fertilization followed by fetal development and birth, with lactation afterward
Production of sex hormones is required for development of secondary sex characteristics and for normal reproductive functions in both sexes