Chapter 27
The Reproductive System
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27
Te noninflammatory type has symptoms that mimic the
inflammatory type, but neither leukocytes nor bacteria ap-
pear in the urine. Its treatment is largely symptomatic.
Benign Prostatic Hyperplasia
Hypertrophy of the prostate,
which is called
benign prostatic hyperplasia (BPH)
and affects
nearly every elderly male. Its precise cause is unknown, but it
may be associated with age-related changes in hormone levels.
It distorts the urethra, and the more the man strains to uri-
nate, the more the valvelike prostatic mass blocks the opening,
enhancing the risk of bladder infections (cystitis) and kidney
damage.
±raditional treatment has been surgical. Newer options
include:
Using microwaves or drugs to shrink the prostate
Inserting and inflating a small balloon to compress the pros-
tate tissue away from the prostatic urethra
Inserting a catheter containing a tiny needle to incinerate ex-
cess prostate tissue with bursts of radio-frequency radiation
Finasteride, which ratchets down production of dihydrotes-
tosterone, the hormone linked to male pattern balding and
prostate enlargement, is helpful in some cases. Additionally,
several drugs are available that relax the smooth muscles at the
bladder outlet, aiding bladder emptying.
Prostate Cancer
Prostate cancer
is the second most common
cause of cancer death in men (a²er lung cancer), accounting for
an estimated 218,000 new cases and 32,000 deaths per year. It
is twice as common in blacks as in whites. Risk factors include
fatty diet and genetic predisposition. XMRV, a retrovirus closely
related to a virus that causes various cancers in mice, has been
implicated in an aggressive form of prostate cancer.
Screening for prostate cancer typically involves digital exam-
ination by a health professional (palpating the prostate through
the anterior rectal wall), assessment of serum PSA levels, and/
or transrectal ultrasound imaging. Although it is a normal
component of blood at levels below 2.5 ng/ml, PSA is a tumor
marker and its rising serum level follows BPH as well as the
clinical disease course of prostate cancer. Screening procedures
are followed by biopsies of suspicious prostate areas, if deemed
necessary, and metastases (most commonly to the pelvic lymph
nodes and the skeleton) are detected by bone or MRI scans.
When possible, prostate cancer is treated surgically, alone
or in conjunction with radiotherapy. Because prostate cancer is
typically androgen dependent, alternative therapies for metas-
tasized cancers involve castration or drugs that block androgen
receptors (flutamide), or inhibit gonadotropin release, such as
LHRH (luteinizing hormone–releasing hormone) analogues.
LHRH is another term for GnRH (gonadotropin-releasing hor-
mone, see p. 1033). Deprived of the stimulatory effects of an-
drogens, the prostatic tissue regresses and urinary symptoms
typically decline. Cryosurgery, chemotherapy, high-intensity fo-
cused ultrasound, and proton beam therapy are now in clinical
trials to assess their benefits.
However, many prostate cancers are slow growing and may
never represent a threat, particularly if the patient is elderly. In
(vesiculase), and prostaglandins, as well as other substances that
enhance sperm motility or fertilizing ability. Te yellow color of
seminal fluid is due to a yellow pigment that fluoresces under
UV light, a capability that allows investigators to recognize a
sperm trail or residue in instances of sexual attack.
As noted, the duct of each seminal gland joins that of the
ductus deferens on the same side to form the ejaculatory duct.
Sperm and seminal fluid mix in the ejaculatory duct and enter
the prostatic urethra together during ejaculation. Seminal gland
secretion accounts for some 70% of the volume of semen.
The Prostate
Te
prostate
(pros
9
tāt) is a single doughnut-shaped gland about
the size of a peach pit (Figures 27.1 and 27.5). It encircles the
urethra just inferior to the bladder. Enclosed by a thick connec-
tive tissue capsule, it is made up of 20 to 30 compound tubuloal-
veolar glands embedded in a mass (stroma) of smooth muscle
and dense connective tissue.
During ejaculation, prostatic smooth muscle contracts,
squeezing the prostatic secretion into the prostatic urethra via
several ducts. Tis fluid plays a role in activating sperm and
accounts for up to one-third of the semen volume. It is a milky,
slightly acid fluid that contains citrate (a nutrient source), sev-
eral enzymes (including fibrinolysin, hyaluronidase, and acid
phosphatase), and prostate-specific antigen (PSA).
Prostate Disorders
Disorders that bedevil the prostate range from inflammations
caused by bacteria, immune cells, or unknown factors, to be-
nign overgrowth of the gland, to prostate cancer. As a result, the
prostate has gained a reputation as a health destroyer (perhaps
reflected in the common mispronounciation “prostrate”). Let’s
take a look.
Prostatitis
Te term
prostatitis
(pros
0
tah-ti
9
tis) refers to a
number of inflammatory disorders with a variety of causes.
Acute bacterial prostatitis is usually due to a bacterial infec-
tion (most commonly
E. coli
) in the prostate. Symptoms may
include a few to several of the following: fever, chills, muscle
and joint pain, frequency, urgency, or painful urination, and
back pain. ±reatment usually includes antibiotics (for up to
four weeks) and pain relief.
Chronic bacterial prostatitis tends to be caused by the same
bacteria as the acute type and has many of the same symp-
toms. However, it is harder to diagnose, and tends to recur
as bacteria in the prostate invade the bladder over and over.
±reatment is difficult and long (three to four months) because
the antibacterial drugs penetrate poorly into the chronically
inflamed prostate.
Chronic prostatitis/pelvic pain syndrome is the most com-
mon and least understood type of prostatitis. It has two man-
ifestations. Tose with the inflammatory type have several of
the urinary tract infection symptoms, as well as pains in the
external genitalia and lower back. Leukocytes, but not bacte-
ria, are present in the urine.
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