Anatomy of the Prostate Gland and Perineal Region- LSRC Flashcards
Where is the prostate located?
Inferior to the urinary bladder and surrounds prostatic urethra
What is the prostate?
Largest accessory gland of male reproductive system
What is the superior part of the prostate close to?
Neck of bladder
What is the apex/inferior of the prostate close to?
Fasia on the superior aspect of the external urethral sphincter
How is the prostate separated from the pubic symphysis?
By the retroperitoneal fat in the retropubic space
What is the urethral crest?
Midline ridge
What is the prostatic sinus
Depression one acc side of urethral crest
How does the prostatic utricle come about?
By fusion of paramesonephric ducts
Arteries of prostate are derived from which artery?
Internal iliac artery
Which branches from internal iliac arteries supply prostate?
Inferior vesicle artery
Internal pudendal and middle rectal arteries
Where do the veins from prostate drain into?
Internal iliac veins
Why do carcinomas of the prostate spread rapidly to the pelvic bone and vertebrae?
Veins drain into Internal iliac veins
The veins continue superiorly with vesicle venous plexus and communicate superiorly with internal vertebral venous plexus that lie in front of vertebral bodies and within neural canal
What are the 2 capsules that the prostate has?
True fibrous capsule- dense and neuromuscular, containing prostatic plexus of veins and nerves
False surrounding fibrous capsular prostatic sheath- composed of condensed visceral layer of pelvic or extra peritoneal fascia
What are the lobes of the prostate?
Inferoposterior lobule
Inferolateral lobule
Superomedial lobule
Anteromedial lobule
What are the zones in the prostate?
Peripheral zone
Central zone (middle love)
Transition zone
What does the prostate secrete?
Milky, acidic fluid
Goes together with secretions from seminal vesicles contributing to volume of semen during ejaculation
Which lobes are affected with hypertrophy of prostate?
Lateral lobe affected
Median lobe involved or affected, obstruction of prostatic urethra may occur, stop urination, increase risk of bladder infections (cystitis) and kidney damage
How are metastases of prostatic cancer spread?
Via lymphatic route- internal iliac and sacral lymph nodes
Venous routes following internal vertebral venous plexus to the vertebrae and brain
Transurethral Resection of the prostate
All or part or just the hypertrophied part could be removed via transurethral resection
Due to close relationship of prostate to prostatic urethra
What is radical prostatectomy
Involve removal of prostate with seminal vesicle, ejaculatory ducts and terminal parts of deferent ducts
Pelvic diaphragm consists of which muscles?
Coccygeus
Levator ani: Pubococcygeus, Iliococcygeus
What does pelvic diaphragm do
Separated pelvic cavity from perineum
Forms roof of perineum
What are the two layers of the superficial layer of perineal fascia
Superficial fatty layer (campers fascia)
Deep membranous layer (Perineal or collet fascia)
What are the two perineal pouches?
Superficial perineal pouch
Deep perineal pouch
What is the superficial perineal pouch?
Space between perineal fascia (inferiorly) and perineal membrane (superiorly)
What is the deep perineal pouch?
Space between perineal membrane inferiorly and inferior fascia of the pelvic diaphragm superiorly and inferior portion of obturator fascia
Rupture of the membranous (intermediate) part of the urethra occurs due to what?
Trauma and fracture of pelvic girdle with separation of pubic symphysis and puboprostatic ligament
What is the result of rupture of membranous part of urethra?
Escape of urine and blood into deep perineal pouch
Fluid may pass superiorly through urogenital and distribute extraperitonealy around prostate and bladder
Cause of rupture of spongy part of urethra- bulb of penis and corpus spongiosum
Trauma like forceful blow to perineum such as falling on metal beam or incorrect transurethral catheterisation
What does rupture of spongy part of urethra lead to??
Urine escaping into superficial perineal pouch
May pass into loose connective tissue in scrotum, penis and superiorly deep to membranous layer of subcutaneous tissue of the inferior anterior abdominal wall
Why can urine not pass into the thighs?
Membranous layer of the superficial perineal fascia blends with the fascia lata (surrounds muscle of thigh) just distal to the inguinal ligament
Why can urine not pass into the anal triangle?
Superficial and deep perineal fascia are continuous with each other around the superficial perineal muscles and with posterior edge of perineal membrane
Where is the ischio-anal fossae?
Located on either side of anal canal
Apex lies superiorly where elevator ani muscle arises from
What is the aschio-anal fossa?
Space filled with fat and loose connective tissue
What are the boundaries of the ischio-anal fossae?
Laterally- ischia and overlapping inferior part of obturator interns, covered with obturator fascia
Medially- external anal sphincter
Superiorly-slopping roof formed by elevator ani muscle
Posteriorly- flutes maximus, sacrotuberous ligament
Anteriorly- bodies of pubic bones
LOOK AT DIAGRAM ON PPT
What are the contents of the ischia-anal fossae?
Fat body- give support for anal canal Neurovascular structures- inc rectal vessels and nerves Cutaneous nerves Perforating branch of S2, S2, Perineal branch of S4 nerve Pudendal canal (Alcock canal)
What is in the pudendal canal?
In lateral wall of ischio-anal fossae
Internal pudendal vessels
Pudendal nerve
Nerve to the obturator interns
The pelvic floor/ roof of perineum is divided into 2 triangles called what? divided by what?
Urogenital triangle anteriorly
Anal triangle posteriorly
Central perineal body- in-between the “2 main holes”
Which muscles make up the pelvic diaphragm?
Levator ani
Coccygeus
