Benign prostatic hyperplasia

So, benign prostatic hyperplasia is the non-cancerous
growth of the prostate gland. This condition is common in men over 50, and
is often considered a normal part of aging.

Learning medicine is hard work!Osmosis makes it easy. It takes your lectures and notes to create
a personalized study plan with exclusive videos,practice questions and flashcards, and so
much more. Try it free today!In benign prostatic hyperplasia, or BPH, prostatic
refers to the prostate gland, hyperplasiameans an increase in the number of cells,
and benign means that these cells aren’tmalignant, so they don’t invade neighboring
tissues. So, benign prostatic hyperplasia is the non-cancerous
growth of the prostate gland. This condition is common in men over 50, and
is often considered a normal part of aging. The prostate is a small gland, about the size
and shape of a walnut, that sits under thebladder and in front of the rectum. The urethra which is the tube through which
urine leaves the bladder, goes through theprostate before reaching the penis. And that part of the urethra is called the
prostatic urethra. The prostate is covered by a capsule of tough
connective tissue and smooth muscle. Beneath this layer, the prostate can be divided
into a few zones. The peripheral zone, which is the outermost
posterior section, is the largest of the zoneand contain about 70% of the prostate’s
glandular tissue. Moving inward, the next section is the central
zone which contains about 25% of the glandulartissue as well as the ejaculatory ducts that
join with the prostatic urethra. Last, is the transitional zone, which contains
around 5% of the glandular tissue as wellas a portion of the prostatic urethra. The transitional zone gets its name because
it contains transitional cells which are alsofound in the bladder. At the microscopic level, each of the tiny
glands that make up the prostate is surroundedby a basement membrane made largely of collagen. Sitting within that basement membrane, is
a ring of cube-shaped basal cells as wellas a few neuroendocrine cells interspersed
throughout. Finally, there’s an inner ring of luminal
columnar cells, which are within the lumenor center of the gland. Luminal cells secrete substances into the
prostatic fluid, that make it slightly alkalinethat give it nutrients which nourish the sperm
and help it survive in the acidic environmentof the vagina. During an ejaculation, sperm leave the testes,
travel through the vas deferens, into theejaculatory ducts, and travel through the
prostatic urethra. Smooth muscles in the prostate contract and
push the prostatic fluid into the urethrawhere it joins the sperm as well as the semen
which is the fluid that comes from the seminalvesicles. The luminal cells also produce prostate specific
antigen, or PSA, which helps to liquefy thegel-like semen after ejaculation, thereby
freeing the sperm to swim. The basal cells and luminal cells of the prostate
rely on stimulation from androgens, or malesex hormones, for survival. The androgens include testosterone, which
is produced by the testicles, and dihydrotestosterone,which is produced in the prostate itself. This androgen is produced by the prostatic
enzyme 5α-reductase which converts testosteroneinto the more potent dihydrotestosterone. Since androgens are steroids, so they can
cross the cell membrane and bind to the androgenreceptors within the cell’s nucleus. This inhibits apoptosis or programmed cell
death, allowing luminal and basal cells inthe prostate to keep growing and multiplying. Dihydrotestosterone is ten times more potent
than testosterone because it can bind to androgenreceptors much longer. Now, after the age of 30, men produce about
1% less testosterone per year. But for unclear reasons, 5α-reductase activity
increases with age, so even with less testosterone,there could be an increase in dihydrotestosterone. Normal prostate cells respond to the increase
in dihydrotestosterone levels by living longerand multiplying – that’s the underlying
cause of benign prostatic hypertrophy. This is a normal process of aging, and around
50% of men develop BPH by the age of 60, andover 90% have it by the age of 85. Fortunately, in BPH there’s no increased
risk for developing cell mutations that leadto prostate cancer. Rather, the entire prostate gland enlarges
pretty uniformly and small hyperplastic nodulescan form within it. These nodules are smooth, elastic, and firm
and are sometimes mistaken for prostate cancer. Typically, hyperplastic nodules will form
in the inner portions of the gland, specificallyaround the prostatic urethra, called the periurethral
zone. When these nodules or the prostate tissue
itself compresses the prostatic urethra, itbecomes more difficult for urine to pass though. So the urine builds up in the bladder causing
it to dilate. In response, the smooth muscle walls of the
bladder will contract harder, and this leadsto bladder hypertrophy were the walls thicken
and become easily irritated. Finally, the stagnation of urine in the bladder
also promotes bacterial growth, and can leadto urinary tract infections. Symptoms of BPH start up when the prostatic
urethra gets obstructed, and it leads to aweak and inconsistent stream of urine, called
dribbling. The person might also have to strain when
urinating to overcome the obstruction, havepain during urination called dysuria, or trouble
initiating urination called hesitancy. As urine builds up in the bladder it causes
a constant sense of incomplete bladder emptying,which increases the frequency of urination
at night – called nocturia. Benign prostatic hyperplasia can be identified
with a digital rectal examination, which iswhere a finger is inserted into the rectum
to feel against the anterior wall of the rectumwhich lies along the posterior prostate. An enlarged prostate could indicate benign
prostatic hyperplasia, while hard nodulescould be a sign of prostate cancer. Levels of prostate specific antigen or PSA,
a substance produced by healthy prostate cells,are also elevated in benign prostatic hyperplasia,
since there are more cells around making thePSA. Treatment of BPH focuses on relieving the
obstruction and allowing the urine to flownormally. This can be done through medications like
finasteride, a 5α-reductase inhibitor, whichshrinks the prostate gland by inhibiting the
conversion of testosterone into dihydrotestosterone. Next, α1-antagonists like phenoxybenzamine
can bind to α1 receptors on the smooth musclesin the neck of the bladder, the prostate,
and urethra, causing them to relax and allowingurine to pass. In some cases, surgical procedures like transurethral
resection of the prostate, or TURP, can bedone to remove part or all of the prostate. All right, as a quick recap, benign prostatic
hyperplasia, of BPH is a condition causedby increased 5α-reductase activity in the
prostate which leads to increased dihydrotestosteroneproduction, and prostate hyperplasia. This is considered to be a normal part of
aging and does not increase the risk of developingprostate cancer. The enlarged prostate gland can obstruct the
prostatic urethra, which will lead to urineretention, causing the bladder to dilate and
hypertrophy. Symptoms of BPH include urinary problems like
urinary hesitancy, dysuria, dribbling, feelingof bladder fullness, and nocturia. BPH treatments include medications like 5α-reductase
inhibitors, α1-antagonists, or a TURP procedure.

Leave a Reply

Your email address will not be published.

This site uses Akismet to reduce spam. Learn how your comment data is processed.

×