Anatomy of the prostate gland and perineum Flashcards
what Gland is doughnut shaped and is the size of a golf ball and is the largest accessory gland of the male reproductive system
where is it located
Prostate gland
Located inferior to the urinary bladder and surrounds the prostatic urethra
the prostate Gland is located inferior to the urinary bladder - what does it surround
prostatic urethra
what are the two parts to the prostate gland
posterolateral glandular -2/3 and anterior fibromuscular one third
superiroly, base is related to the neck of the bladder
inferiorly the apex of the prostate rests on external sphincter of neck of bladder and deep peritoneal muscles
what space separates the anterior surface of the prostate from the pubic symphysis
retroperitoneal fat in the retropubic space - cave of retries
Anterior to the urethra is the narrow fibromuscular isthmus.
Posterior surface related to the ampulla of the rectum.
Inferolateral surfaces related to the levator ani muscle.
Ejaculatory ducts enter the upper posterior part to open into the urethra, on either side of the prostatic utricle.
what is the prostatic sinus
depression on each side of the urethral crest ( midline ridge)
where do you find the seminal colliculus
eminence in the middle of the urethral crest
prostatic arteries are derived from what arteries
branches of internal iliac artery
inferior veiscal
internal pudendual and middle rectal arteries
veins are found between the true fibrous capsule and false prostatic sheath around the side of the base of the prostate. What is the plexus called
prostatic plexus - veins receive the dorsal vein of the penis and drain into internal iliac veins
also continues with internal veterbral venous plexus infant of vertebral bodies within the neural canal - this explains why carcinoma of the prostate spreads readily to pelvic bone and vertebrae - these veins are valveless and constitute the valves vertebral veins of batson
how many capsules does the prostate have
2
true capsule - dense and neruovascular - contains the prostatic plexus of veins and nerves
a false one - surrounds capsular prostatic sheath composed of condensed visceral layer of pelvic or extra( retro) peritoneal fascia - blends with the retrovesical septum
How many lobes of the prostate are there
how many lobules and what are they called
2 - right and left divided into 4 lobules -by relationship with the urethra and ejaculatory ducts
- inferoposterior ( lower posterior lobule)
- inferolateral ( lower lateral) lobule
superomedial
anteromedial
3 zones of the prostate - preferred by clinicians
peripheral zone
central zone
transition zone
what does the prostate develop from
do individual prostatic glands retain their own ducts?
from urethral epithelium into surrounding wall of urethra
they enlarge the wall
yes they empty independently into prostatic sinuses on posterior aspect of urethral lumen
what does the prostate secrete
milky acidic fluid , together with seminal vesicle contributes to volume of the semen during ejacualtion
what condition are the lateral lobes enlarged usually affected and common between middle aged men and can affect the median lobe which could obstruct prostatic part of the urethra and impeded uriantion increasing the risk of bladder infection ( cystitis) as well as kidney damage)
hypertrophy of the prostate
- benign hypertrophy
how can you check for the hypertrophy of the prostate
rectal examination - more readily palpable to examine enlargement in a full bladder via rectum
where do metastases of prostatic cancer spread to via lymphatic route initially and to internal iliac and sacral lymph nodes and via venous route following the internal venous plexus to where
vertebrae and brain
what Is a prostatectomy
TURP - all or part removed being careful not to damage prostatic urethra , very enlarged prostatectomy carried out retropubically - capsule
what is TURP
transurethral resection of the prostate - preserves nerves and BV associated with true capsule that pass to and from the pens increase patients chance of sexual function as rwell as restoring normal urianry control
what could radical prostatectomy involve
Radical prostatectomy could involve the removal of the prostate with the seminal vesicle, ejaculatory ducts and terminal parts of the deferent ducts.
what is the perineum
The region of the body that lies between the upper part of the medial surface of the thighs and the buttocks, extending posteriorly from the coccyx to the pubis anteriorly and superiorly (deep) up to the pelvic diaphragm.
It includes the anus and external genitalia:
the penis and scrotum of the male and the vulva/vagina of the female.
the roof of the perineum is formed by what
pelvic diaphragm -
what are the two triangles joined by a line between the 2 ischial tuberostitees dividing the perineum into 2
urogenital triangle anteriorly
the anal triangle postieroly
the midpoint of the line joining the ischial tuberostiites is the location of what
the central perineal body or tendon
Perineal fasciae consists Superficial and Deep layers
the superficial layer is made of 2 layers what are they
difference between men and women
superficial fatty layer
females - fatty tissue of labia major and mon pubis and goes anteriorly to lower anterior abdominal wall
males - diminished and replaced in the penis with smooth muscle ( darts) and goes lateral and superiorly with campers facias of lower abdominal wall
Some deep fascia stuff
Deep membranous layer of superficial perineal fascia (Perineal or Colles fascia).
Extends laterally and attach to the fascia lata of the thigh.
In males: continues anteriorly with the Dartos fascia of the penis and scrotum, becomes continuous superiorly with the Scarpa’s fascia of the lower anterior abdominal wall.
In females: it also becomes continuous with the Scarpa’s fascia of the lower anterior abdominal wall.
Deep layer of Perineal Fascia (Investing or Gallaudet Fascia).
Invests the ischiocavernosus, bulbospongiosus and superficial transverse perineal muscles.
Laterally attached to ischiopubic rami.
Anteriorly fuses with the suspensory ligament of the penis/clitoris and continues superiorly with the deep fascia of the lower anterior abdominal wall.
in the urogenital triangle - a perinoenal membrane stretches over the anterior part of pelvic outlet - urogenital hiatus
does the urethra perforate this
yes
the superficial perineal pouch is a space between the perennial fascia and perineal membrane - what binds this laterally
ischiopubic rami
in males what structures are contained in the superficial perineal pouch
root of penis
proximal part of spongy urethra
superficial transverse perineal muscles
deep perineal branches of internal prudential vessels and nerves
in females what structures are contained in the superficial perineal pouch
clitoris and associated muscle ( ichiovavernosus)
bulb of vestibule
greater vestibular glands
same as male last 2
what is the deep perineal pouch
space between perineal membrane ifnerioly and inferior facia of diaphragm superiorly and obturate interns muscle laterally.
what is contained in both sexes in the deep perineal pouch
centrally the urethra
external sphincter muscles above the centre of perineal membrane surrounding the urethra
anterior extension of the ischia-anal fat pads
Contents in Males:
Intermediate part of the urethra, the narrowest part of the male urethra.
Deep transverse perineal muscles.
Bulbo-urethral glands.
Dorsal neurovascular structures of the penis.
Contents in Females:
Proximal part of the urethra.
Deep transverse perineal muscles?.
Dorsal neurovasculature of the clitoris.
what can cause rupture of the membranous part of the urethra
trauma and fracture of pelvic grille with separation of Pubic symphysis and puboprostatic ligament
leads to extravasation of urine and blood into the deep peritoneal pouch - fluid may go superior to urogenital hiatus and distribute extraperitoneally around prostate and bladder
what does rupture of the spongy part of the urethra 9 particularly at the blue of the penis and corpus spongisum due to trauma or blow or incorrect transurethral cathertisation , rest to
urine extravasating into superficial perineal pouch - along peritoneal fascia - may go to scrotum
The urine cannot pass into the thighs because the membranous layer of the superficial perineal fascia blends with the fascia lata just distal to the inguinal ligament.
The urine also cannot pass posteriorly into the anal triangle because the superficial and deep perineal fascia are continuous with each other around the superficial perineal muscles and with the posterior edge of the perineal membrane.
Rupture of blood vessels into the superficial perineal pouch will result in similar containment of blood in the superficial perineal pouch.
where is the ischia anal fossa located
each side of anal canal - wedge shaped either side
apex of this fossa is superiorly to leavator and muscle filled with fat and loose connective tissue
how to the 2 ischia anal fossa communicate with each other
via the deep perineal pouch
boundaries of the ischia anal fossa
Extends into the urogenital triangle superior to the perineal membrane as the Anterior recesses of the Ischio-anal fossae.
Boundaries are:
Laterally by the ischium and overlapping inferior part of the obturator internus, covered with obturator fascia.
Medially by the external anal sphincter.
Superiorly by a slopping roof formed by the levator ani muscle.
Posteriorly by the sacrotuberous ligament and gluteus maximus.
Anteriorly by the bodies of the pubic bones
what is contained in the ischia anal fossae
Filled with fat body of the ischio-anal fossa, which provide support for the anal canal.
Fibrous bands that traverse the fat bodies.
Neurovascular structures including the inferior anal (rectal) vessels and nerves.
Cutaneous nerves.
Perforating branch of S2 and S3.
Perineal branch of S4 nerve.
The pudendal canal (Alcock canal) and its neurovascular bundle in the lateral wall of ischio-anal fossae.
Internal pudendal vessels.
Pudendal nerve.
Nerve to the obturator internus.
ischio anal and peri-anal abscesses
May be site of infection leading to formation of painful ischio-anal abscesses.
Shows as fullness and tenderness between the anus and the ischial tuberosity.
Infection may reach the ischio-anal fossae in the following ways:
After cryptitis (inflammation of the anal sinuses.
Extension from a pelvirectal abscess.
After a tear in the anal mucous membrane.
From a penetrating wound in the anal region.
From anal fissure.
An abscess in one fossa my spread to the other due intercommunication posteriorly via the deep post-anal space.
