Anatomy, Physiology, and Sonography of the Prostate Gland and Seminal Vesicles

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the prostate is a

retroperitoneal gland

the prostate produces and secretes an

alkaline fluid that constitues between 14-30% of the volume of semen

the prostate gland is located

inferior to the urinary bladder, between the symphysis pubis and the rectum

the shape of the prostate

inverted pyramid

the base of the prostate is located

superior

the apex of the prostate gland is positioned

inferior

the prostate urethra is used as a —, travels through the center of the prostate

point of reference for the zones

the anterior fibromuscular stroma is located —, and is of little clinical significance

anterior to the prostatic urethra

The paired seminal vesicles are located

superior to the prostate gland and posterior to the base of the bladder

the paired seminal vesicles secrete am alkaline-based fluid and —

empty into the paired ejaculatory ducts

The ejaculatory ducts are formed by the

union of the seminal vesicles and ductus deferens

These tiny ducts travel through the prostate and empty into the urethra at an area called the —

verumontanum

— imaging is used for biopsies and provides superior resolution

transrectal

— imaging is useful for measuring the overall size of the prostate

Transabdominal

The prostatic zones are typically — and may be differentiated by visualizing landmarks such as the prostatic urethra and ejaculatory ducts

homogeneous

location of the peripheral zone

posterior lateral, apical gland

location of the central zone

base of prostate

location of the transitional zone

on both sides of the proximal urethra

location of the periurethral glandular zone

embedded in the muscle of the proximal urethra

significance of the peripheral zone

1. largest prostatic zone

2. most common site for malignancy

significance of the central zone

1. second largest prostatic zone

significance of the tranisitional zone

1. site for benign prostatic hyperplasia

2. second most common site of malignancies

significance of the periurethral glandular zone

1. smallest prostatic zone

Zonal anatomy of the prostate in the sagittal plane.

The seminal vesicles appear as hypoechoic structures between the

bladder and prostate