primarily to the first part of the ejaculate and includes acid phosphatase,
spermine (a polyamine), fibrolysin, amylase, and zinc. Spermine oxidation
results in the musky odor of semen, and fibrolysin is responsible for the
liquefaction of semen after ejaculation. Acid phosphatase and prostatic-
specific antigen are important for the diagnosis of metastases. The thyroid
synthesizes T 3 and T 4 (answer b); the lactating mammary gland produces
milk(answer e).
243.The answer is c.(Young, pp 329, 336, 341, 357, 368–371. Junqueira,
pp 429, 430.)The figure is a light micrograph of the epididymis which func-
tions in the storage, maturation, and phagocytosis of sperm. In addition, the
epididymis is involved in the absorption of testicular fluid and the secretion
of glycoproteins involved in the inhibition of capacitation. The epithelium
of the epididymis is pseudostratified with stereocilia (long microvilli), and
the wall contains extensive connective tissue. The seminal vesicle (answer b)
produces fructose and prostaglandins and contains a thick smooth muscle
layer. Sperm are often found in the lumina. Spermiogenesis occurs in the
testes (answer a). Milk production occurs in the mammary gland
(answer e),which contains alveoli and lactiferous ducts. Implantation
occurs in the uterus (answer d),which is lined by a simple columnar
epithelium with endometrial glands that differ in arrangement, depending
on the phase of the cycle (long and straight in the proliferative phases and
S-shaped in the secretory phase). The myometrium, composed of smooth
muscle, is hormone-sensitive and undergoes both hypertrophy and hyper-
plasia during pregnancy and atrophy after menopause, resulting in a
shrinking of the uterus in postmenopausal women.
244.The answer is e.(Kierszenbaum, p 533. Junqueira, pp 426–427. Sadler,
pp 240–242. Moore and Persaud, pp 325–326.)The development of the testis
from an indifferent gonad depends on the presence of the testis-determining
factor, a gene on the short arm of the Y chromosome. During fetal develop-
ment, the production of androgens by the developing testis results in mas-
culinization of the indifferent gonadal ducts and the indifferent genitalia
(answer c).In the absence of androgens, female genitalia and female ducts
(vagina, oviducts, and uterus) develop. In the mature male, testosterone is
required for the initiation and maintenance of spermatogenesis as well as the
structural and functional integrity of the accessory glands and ducts of the
Reproductive Systems Answers 377