Chapter 19: The Male Pelvis
Ultrasound examinations of male pelvis are indicated for prostate gland:
-Size and echo texture -Prostatitis (infection) -Detection of masses -Evaluation of benign prostatic hypertrophy (BPH) -Sonographic correlation of evaluated serum prostatic specific antigen (PSA) -Evaluation of postoperative transurethral resection (TURP) -Ultrasound-guided biopsies of prostatic lesions
what is the transitional zone?
1 of 4 zones of prostate gland. Only about 5%. Has 2 lobes laterally of proximal prostatic urethra superior to the verumontanum
Common Diagnostic Tests
MRI, Sonography
What is the prostate shaped like?
a cone with a central core (the prostatic urethra)
What is the prostate gland?
a gland surrounding the neck of the bladder in males and releasing prostatic fluid.
The prostate gland is surrounded by?
a thin capsule consisting of dense fibrous tissue and smooth muscle
What does the seminal vesicle secrete?
a viscous fluid rich in fructose
The prostate and seminal vesicles secrete what kind of fluids?
alkaline
What does BPH cause?
incomplete emptying, retention, increased frequency, urgency, nocturia weak stream, straining to void, dribbling, incontinence, hematuria
The apex of the prostate is the?
inferior margin and exit for urethra
The neurovascular bundle of the prostate gland courses along the __________ border.
posterolateral
The anterior fibromuscular stroma is located anterior to the?
prostatic urethra
The prostate gland is divided into right and left lateral lobes by the
prostatic urethra.
The prostatic urethra is divided by the verumontanum into what segments?
proximal and distal
what is the glandular region?
posterior and largest portion of the prostate gland
Ultrasound examinations of male pelvis are indicated for: Seminal Vesicles
- Evaluation of size, symmetry, and echo texture - Ruling out presence of cysts or calculi - Inflammatory processes
How much prostate fluid is in semen?
13% to 33%
Define ejaculatory ducts
2 ducts that course through the prostate gland and empty into the prostatic urethra
The Central Zone is how much percentage of the glandular prostate?
20%
what is the normal measurement of the prostate?
3.8cm in length, 3cm anteroposterior, 4cm wide
The prox and distal segments of the verumontanum form an angle of?
35 degrees
what is the normal measurement of the seminal vesicles?
5cm in length, less than 1cm in diameter
How much seminal vesicle fluid is in semen?
60%
What is the most inferior organ of the male pelvis?
Prostate
Where is most prostatic pathology located?
in the glandular areas
The prostate is best seen using what technique?
Transrectal because of the close proximity of prostate and rectum
Define fibromuscular region
anterior and smallest portion of the prostate gland
where is the fibromuscular region located?
anterior to the prostatic urethra
How much does the prostate weigh?
approx. 20g
What is the verumontanum?
area where ejaculatory ducts join urethra, close to the center of the prostate
The transabdominal method for scanning the prostate is used only to?
assess the size of the glands due to most pathology and zones not being clearly seen
Why does the prostate gland sometimes enlarge with age?
benign changes, infection, malignant tumors, or other causes
What zones cant be individually distinguished?
central zone and transition zone
The seminal vesicles are encapsulated by?
connective tissue
what are the 4 zones of the prostate glandular region?
peripheral, central, transition, and periurethral
Where do the seminal vesicles empty into?
distal portion of the ductus (vas) deferens to form the ejaculatory ducts
What is BPH (benign prostatic hyperplasia)
enlargement of the prostate gland
The prostate gland contains glandular and nonglandular elements that consist of
fibromuscular stroma and the prostatic urethra
What does the prostate fluids do for the sperm?
helps with sperm visibility
What is the prostate gland relative to the seminal vesicles?
hyperechoic
How are periurethral tissues relative to the urethra?
hypoechoic
what is the peripheral zone of the prostate?
largest of all 4 zones of the posterior glandular portion of the prostate gland and occupies the area lateral and posterior to the distal prostatic urethra
Normal serum PSA
less than 4.0 ng/mL
The glandular elements of the prostate gland are anatomically divided and classified into
lobes and zones
Transrectally, the seminal vesicles appear at what echogenicity?
low grey
Only biopsy can rule out ___________
malignancy
The prostatic urethra eventually transitions to the
membranous, also called the sphincteric urethra
what is semen?
mixture of sperm and seminal fluid
What is the levator ani?
muscle that supports the prostate gland laterally
what is the obturator internus muscle?
muscle that supports the prostate gland laterally
what is the periurethral glandular zone?
one of the 4 zones of the glandular portion of the prostate. consists of tissue that lines the proximal prostatic urethra
define ductus (vas) deferens
one of the two muscular tubes, each joining with its corresponding seminal vesicle to form an ejaculatory duct
The __________ zone of the prostate gland is the site of a majority of prostate malignancies.
peripheral
What is the P-zone?
peripheral zone
What zone is more hyperechoic and homogenous in comparison to others?
peripheral zone
what is the prostatic urethra?
portion of urethra that passes through prostate gland
Normal prostate gland should appear?
semilunar near base (superiorly) and rounded near apex (inferiorly) , heterogenous with medium echoes, symmetric
Lab Values
serum prostatic specific antigen
The base of the prostate gland is the?
superior aspect which is in contact with the urinary bladder
Normal seminal vesicles should appear?
symmetric and isoechoic
What is believed about the fluid from the prostate in reproduction?
that it neutralizes the acid environment of the vagina, uterus, and fallopian tubes
Which zones are the most discernable zones of the prostate?
the P-zone and T-zone
The seminal vesicles angle medially to what?
the apex of the bladder
what does the transitional zone border?
the central zone posteriorly and laterally and the fibromuscular tissue anteriorly
What is the prostate separated posteriorly from the rectum by?
the denonvilliers fascia
What courses through the central zone of the prostate?
the ejaculatory ducts
What does the prostate gland lie behind?
the pubic symphysis
What lies posterior to the urinary bladder and just superior to the prostate?
the seminal vesicles
Where is the central zone of the prostate located?
the superior edge bordering the bladder and seminal vesicles
What is the most important function of the male reproductive system?
to produce sperm
What is the T-zone?
transitional zone
What are the seminal vesicles?
two pouch like structures between the bladder and the rectum connected to the prostate that secrete an alkaline viscous fluid rich in fructose that aids to sperm viability
Define Denonvilliers Fascia
two-layered fascia separating the prostate gland from the rectum
An average-sized prostate gland in an adult male patient is __________.
walnut-sized
