Erectile dysfunction (ED), the inability to achieve or maintain an erection, is considered a cause of infertility in men. Various factors can contribute to ED, including insufficient androgen production, neurovascular damage (such as from diabetes mellitus or spinal cord injury), structural damage to the penis, perineum, or pelvis, psychogenic factors (such as depression or performance anxiety), and the use of prescribed medications and recreational drugs, including alcohol and tobacco. One significant advancement in the treatment of certain forms of erectile dysfunction is the use of selective cGMP phosphodiesterase inhibitors, which aid in sustaining an erection. Andropause, a distinct term for male menopause, does not exist. However, as men age, their gonadal sensitivity to LH decreases and androgen production decreases as well. Consequently, serum LH and FSH levels rise. While sperm production typically begins to decline after the age of 50, many men are still able to maintain reproductive function and spermatogenesis throughout their lives.

The female reproductive system comprises the ovaries, known as gonads, and the female reproductive tract, which includes the oviducts, uterus, cervix, vagina, and external genitalia.

The Ovary
Situated within a fold of peritoneum called the broad ligament, the ovary is usually positioned near the lateral wall of the pelvic cavity. Since the ovary extends into the peritoneal cavity, eggs that have been ovulated briefly reside within this cavity before they are captured by the oviducts.

The ovary consists of an outer cortex and an inner medulla. The medulla of the ovary is innervated by neurovascular elements. The cortex, which is composed of a densely cellular stroma, contains the ovarian follicles. These follicles enclose a primary oocyte surrounded by follicle cells. The cortex is covered by a connective tissue capsule called the tunica albuginea.

Collapse of venous return from cavernous spaces
Contraction of muscles around the base of the penis

Figure 44.12A illustrates the arrangement of the vasculature and cavernous tissue within the penis. In the flaccid state, blood flow into the cavernous spaces is limited due to the contraction of the helicine arteries. Figure 44.12B outlines the neurovascular events that lead to penile erection.

(From Bhasun S et al. In: Larsen P et al [eds]. Williams Textbook of Endocrinology. 10th ed. Philadelphia: Saunders; 2003.)

CHAPTER 44 The Male and Female Reproductive Systems 799
Inabilitytoachieveormaintainanerectionistermederectile dysfunction (ED) andisonecauseofinfertilityinmen.MultiplefactorscanleadtoED,includinginsufficientandrogenproduction;neurovasculardamage(e.g.,fromdiabetesmellitus,spinalcordinjury);structuraldamagetothepenis,perineum,orpelvis;psychogenicfactors(e.g.,depression,performanceanxiety);andprescribedmedicationsandrecreationaldrugs,includingalcoholandtobacco.AmajordevelopmentinthetreatmentofsomeformsoferectiledysfunctionisuseofselectivecGMPphosphodiesteraseinhibitorsthatassistinmaintaininganerection(see
Fig.44.12B
There is no distinct andropause in men. However, as men age, gonadal sensitivity to LH decreases and androgen production drops. As this occurs, serum LH and FSH levels rise. Although sperm production typically begins to decline after age 50, many men can maintain reproductive function and spermatogenesis throughout life.
The female reproductive system is composed of the gonads, called ovaries, and the female reproductive tract, which includes the oviducts, uterus, cervix, vagina, and external genitalia.
The Ovary
The ovary is located within a fold of peritoneum called the broad ligament, usually close to the lateral wall of the pelvic cavity (
Fig. 44.13 ). Because the ovary extends into the peritoneal cavity, ovulated eggs briefly reside within the peritoneal cavity before they are captured by the oviducts.
The ovary is divided into an outer cortex and inner medulla (
Fig. 44.14 ). Neurovascular elements innervate the medulla of the ovary. The cortex of the ovary is composed of a densely cellular stroma. Within this stroma reside the ovarian follicles (see
Fig. 44.14, F ), which contain a primary oocyte surrounded by follicle cells. The cortex is covered by a connective tissue capsule, the tunica albuginea, (tactile, visual, auditory, psychic)
Collapse of venous return from cavernous spaces
Contraction of muscles around base of penis • Fig. 44.12 A, Arrangement of the vasculature and cavernous tissue within the penis. During the flaccid state, blood flow into the cavernous spaces is limited by contraction of the helicine arteries. B, Outline of neurovascular events leading to penile erection. (A, From Bhasun S et al. In: Larsen P et al [eds]. Williams Textbook of Endocrinology. 10th ed. Philadelphia: Saunders; 2003.)
CHAPTER 44 The Male and Female Reproductive Systems 799