Similar to embryological development in the female, the male genital organs develop in the abdomen of the fetus, but are immature. The testes develop near the kidneys and
descend into the scrotum through the inguinal canal after 35 weeks’ gestation. Scrotal examination is an important component of the male neonate’s physical assessment to ensure that the testes have descended and do not remain in the inguinal canal. Cryptorchidism is the condition in which the testes fail to descend; sterility results unless the testes are surgically placed in the scrotum (Scanlon &
Sanders, 2003) (See Chapter 18 for further discussion). It is important to locate both testes in a newborn as testicu- lar failure to descend may indicate gonadal malgenesis, which can lead to testicular cancer and fertility issues in young adulthood.
The reproductive functions of the testes begin at the time of puberty. Once critical hormone levels have been reached, the fi nal stages of reproductive system develop- ment take place. A gradual decline in hormone produc- tion normally occurs during late adulthood. Although the hormonal decline may be associated with a decrease in sexual desire and fertility, most men maintain the ability to reproduce into old age.
Now Can You— Discuss aspects of the male reproductive system?
1. Identify the three external structures of the male reproductive system and describe one function for two of them?
2. Discuss the functions of the testicles, epididymis, vas deferens and prostate gland?
3. Trace the pathway from sperm production to semen ejaculation?
4. Name fi ve male secondary sex characteristics that result from the infl uence of testosterone?
s u m m a r y p o i n t s
◆ Gender is determined at the moment of conception.
Identifi able sexual characteristics are apparent in the embryo at 8 weeks of gestation.
◆ Gender maturation is a lengthy process that begins during embryonic development and reaches full matu- rity during late adolescence.
◆ External structures of the female reproductive system include the mons pubis, labia, clitoris, vestibule, ure- thral meatus, Skene’s and Bartholin’s glands, vaginal introitus, hymen and perineum.
◆ Internal structures of the female reproductive system include the ovaries, fallopian tubes, uterus, and vagina.
◆ The female bony pelvis supports and protects the con- tents of the pelvis and provides a fi xed axis for the pro- cess of childbirth.
◆ The breasts or mammary glands are considered to be accessory organs of the female reproductive system.
◆ Hormones secreted by the pituitary gland are essential in the regulation of gonadal, thyroid and adrenal function, lactation, body growth, and somatic development.
◆ Menstruation and ovulation are controlled by a com- plex interplay of positive and negative feedback systems associated with hormones released by the hypothala- mus, pituitary, and ovaries.
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chapter 5 Reproductive Anatomy and Physiology 135
◆ The male reproductive system consists of the testes, where spermatogonia and male sex hormones are formed; a series of continuous ducts that allow sper- matozoa to be transported outside the body; accessory glands that produce secretions to foster sperm nutri- tion, survival, and transport; and the penis, which functions as the reproductive organ of intercourse.
◆ Testosterone, the dominant male hormone, is respon- sible for the development of secondary sex characteris- tics in the male.
r e v i e w q u e s t i o n s
Multiple Choice
1. The perinatal nurse explains to the new nurse that a female fetus has a developed ovary by
A. 8 weeks B. 10 weeks C. 12 weeks D. 16 weeks
2. The perinatal nurse describes to the prenatal class attendees that an incision for a Cesarean birth is normally made in the uterine segment known as the:
A. Isthmus B. Cervix C. Apex D. Corpus
3. The perinatal nurse knows that ova are produced and estrogen secreted at the time of:
A. Puberty B. Birth
C. The climacteric D. Pregnancy
4. The perinatal nurse teaches the new nurse that the assessment landmark for the fetal presenting part is the:
A. Ischial spines B. Sacral promontory C. Sacral alae
D. True pelvis Fill-in-the-Blank
5. The clinic nurse teaches the new nurse that the fallopian tubes or _______ measure about _______
inches (_______cm) and are vulnerable to infection which can cause _______ and increase the risk of _______ pregnancy.
6. The perinatal nurse knows that uterine circulation is supplied by the _______ and _______ arteries, which are _______ until the uterus expands during pregnancy.
7. The clinic nurse is aware that when a woman is undergoing a PAP test and physical examination, it is not always possible to visualize the ______ glands located on either side of the _______. These glands are responsible for mucus production that _______
the vagina.
True or False
8. The perinatal nurse knows that beginning at the 12th gestational week, a male fetus produces androgens that stimulate growth of the external genitalia.
Select All that Apply
9. The perinatal nurse describes the multiple functions of the uterus as:
A. Providing a safe environment for a growing embryo
B. Providing a passageway for sperm C. Providing nourishment for the zygote
D. Providing a blood supply for the accessory organs
10. The perinatal nurse knows that the internal urinary system is composed of:
A. Ureters B. Urethra C. Vagina D. Bladder
See Answers to End of Chapter Review Questions on the Electronic Study Guide or DavisPlus.
REFERENCES
Blackburn, S.T. (2003). Maternal, fetal, and neonatal physiology: A clinical perspective (2nd ed.). St. Louis: W.B. Saunders.
Bulechek, G., Butcher, H.M., & Dochterman, J. (2008). Nursing interven- tions classifi cation (NIC) (5th ed.). St. Louis, MO: C.V. Mosby.
Caldwell, W., & Moloy, H. (1933). Anatomical variations in the female pelvis and their effect in labor with a suggested classifi cation.
American Journal of Obstetrics and Gynecology, 26, 479–505.
Chumlea, W.C., Schubert, C.M., Roche, A.F., Kulin, H.E., Lee, P.A., Himes, J.H., & Sun, S.S. (2003). Age at menarche and racial compari- sons in U.S. girls. Pediatrics, 11(1), 110–113.
Cunningham, F., Leveno, K., Bloom, S., Hauth, J., Gilstrap III, L. &
Wenstrom, K. (2005). Williams Obstetrics (22nd ed.). New York:
McGraw-Hill.
Dillon, P.M. (2007). Nursing health assessment: A critical thinking, case studies approach (2nd ed.). Philadelphia: F.A. Davis.
Fehring, R., Schneider, M., & Raviele, K. (2006). Variability in the phases of the menstrual cycle. Journal of Obstetric, Gynecologic and Neonatal Nursing, 35(3), 376–384.
Garibaldi, L. (2004). Physiology of puberty. In Nelson, W.E., Behrman, R.E., Kliegman, R.M., & Arvin, A.M. (Eds.). Nelson textbook of pedi- atrics (14th ed., p. 1862). Philadelphia: W.B. Saunders.
Johnson, M., Bulechek, G., Butcher, H., McCloskey Dochterman, J., Maas, M., Moorhead, S., & Swanson, E. (2006). NANDA, NOC, and NIC Linkages: nursing diagnoses, outcomes, & interventions (2nd ed.).
St. Louis, MO: Mosby Elsevier.
Moorehead, S., Johnson, M., Mass, M., & Swanson, E. (2008) Nursing outcomes classifi cation (NOC) (4th ed.). St. Louis, MO: C.V.
Mosby.
Moskosky, S., Ed. (1995). Women’s health care nurse practitioner certifi ca- tion review guide. Potomac, MD: Health Leadership Associates, Inc.
Scanlon, V.C., & Sanders, T. (2007). Essentials of anatomy and physiology (5th ed.). Philadelphia: F.A. Davis.
Shier, D., Butler, J., & Lewis, R. (2003). Hole’s essentials of human anatomy and physiology (8th ed.). New York: McGraw-Hill.
Speroff, L., Glass, R., & Kase, N. (1999). Clinical gynecology, endocrino- logy, and infertility (6th ed.). Baltimore: Lippincott Williams &
Wilkins.
Tanner, J.M. (1962). Growth at adolescence (2nd ed.). Oxford: Blackwell Scientifi c.
Venes, D. (2009). Taber’s cyclopedic medical dictionary (21st ed.).
Philadelphia: F.A. Davis.
For more information, go to www.Davisplus.com
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136 unit two The Process of Human Reproduction
Female Male
Hormonal influences on reproduction:
Hypothalamus: releasing factors gonadotropin releasing hormone;
corticotropin releasing hormone;
growth hormone releasing factor/
inhibiting factor;
thyrotropin releasing hormone;
prolactin inhibiting factor
Pituitary: ACTH; prolactin; growth hormone;
gonadotropins; oxytocin
Gonadal: estrogen; progesterone; testosterone In addition: hCG, prostaglandins; relaxin
Physical, psychological
& emotional changes Internal:
• Ovaries=oogenesis
• Fallopian tubes
• Uterus - Corpus - Isthmus - Cervix
• Vagina
• Ligaments/muscles supporting uterus
External:
• Vulva
- Labia majora/minora - Clitoris
- Vaginal vestibule - Vaginal opening - Bartholin’s glands
• Mons pubis
• Skene’s glands
• Hymen
• Perineum
• Thelarche
• Menarche
• Hypothalamus/pituitary/
ovarian axis development of secondary sex characteristics Menstrual cycle:
• Begins in puberty
• Changes occur in uterus, cervix and vagina
• Controlled by hormones via positive and negative feedback
Uterine cycle:
• Proliferative phase
• Secretory phase
• Ischemic phase Hypothalamic-pituitary- ovarian cycle:
• Interaction of GnRH, LH, FSH, estrogen and progesterone that promote:
- Ovarian follicle growth, ovulation, luteinization - Onset of menstruation Bony pelvis:
• Supports/protects pelvic contents
• Fixed axis for birth passage
Breasts:
• Nipples/areola
• Montgomery tubercles
• Alveoli/lactiferous ducts
Types:
• Gynecoid
• Android
• Anthropoid
• Platypelloid
Measurements/
Pelvimetry:
• Pelvic inlet
• Midpelvis
• Pelvic outlet
Internal:
• Testes
• Epididymis
•Vas deferens
• Ductus deferens
• Ejaculatory ducts
•Urethra
• Spermatic cords
• Accessory glands
• Reproductive function of testes begins
• Enlargement of testes
• Development of secondary sex characteristics
• Growth spurt
• Sperm production External:
• Perineum
• Pelvis
• Scrotum Structures of the female
reproductive system
Other
Puberty At 5 weeks:
Begin male/female differentiation in embryo
Reproductive Anatomy & Physiology
Structures of the male reproductive system
Now Can You:
• Discuss various aspects of the female and male reproductive systems
• Identify aspects of the bony pelvis and female breast
• Discuss key hormones involved in reproduction
• Discuss concepts related to puberty
CONCEPT MAP
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137