Sem 2 - B - Male pelvic contents and the anal triangle - Vas deferens, prostate, seminal vesicle, anal triangle/canal/sphincters Flashcards
The vas deferens is a muscular tube that helps with the transport of sperm Describe the route of the vas deferens?
The vas deferens is a muscular tube that transports sperm from the epididymis to the ejaculatory duct. It travels within the spermatic cord through the inguinal canal and rings before turning medially once it reaches the lateral pelvic wall before travelling downwards to join with the seminal gland ducts located posteriroly to the bladder - this union forms the ejaculatory duct
How are you able to distinguish between ureter and vas deferns when inside the pelvis? Where is the vas deferens in relation to the inferior epigastric vessels/
The ureter travel inferiorly from the kidneys and crosses the bifurcation of the common iliac arteries
Vas deferens comes from lateral pelvic wall crossing the external iliac artery
The vas deferens exits the deep inguinal ring, lateral to the inferior epigastric artery and then goes posterior to travel medially towards the seminal gland
Where does the ejaculatory duct drain into?
The ejaculatory duct drains sperm into the prostatic urethra located within the prostate gland
How many seminal vesicles are there? What is the size of the seminal vesicles? (coiled and uncoiled) Name two things the seminal vesicle adds to the sperm
There are two seminal vesicles (right + left)
The seminal vesicles are approximately 5cm and 10-15cm in length if uncoiled
The seminal vesicles the liquid component of sperm as well as fructose - this gives the sperm energy and allows the sperm to swim more efficiently
Restate the blood supply to the bladder What is the arterial supply to the seminal vescile?
Arterial supply to bladder
- 2x superior vesical arteries from each side
- One inferior vesical artery from each side (these are branches from the internal iliac artery)
Arterial supply to the seminal vesicle
- Inferior vesical artery and the prostatic artery (branch of inferior vesical artery)
What is the nervous innervation of the seminal vesicle?
The seminal vesicle innervation like much of the male genitalia is via sympathetic innervation
If feeling the end of the bladder, can push the fingers further down to feel the prostate gland in the male What does the prostate gland secrete into the urethra to add to the semen?
The prostate gland secretes proteolytic enzymes and acid phosphatase into the semen to prepare the sperm to meet and penetrate the egg
What is the blood supply to the prostate gland? What is the drainage of the prostate gland?
Prostate gland blood supply - prostatic arteries arise mainly from the internal pudendal artery, middle rectal artery, inferior vesical artery
The prostate gland drains into the prostatic venous plexus which drains into the internal iliac vein (this also drains the deep dorsal vein of the penis)
How is the internal iliac vein drianage related to the vertebral venous plexus?
Batson’s venous plexus is a valveless network connecting the deep pelvic veins - internal iliac vein mainly - and thoracic veins to the internal vertebral venous plexus and is therefore believed to provide a route for metastases to the vertebral column from primary cancers ie prostate
What is the neck of the bladder supported by in males and females?
In females the neck of the bladder is held in place by the pubovesical ligament
In males the neck of the bladder is held in place by the puboprostatic ligament
Puboprostatic ligament also helps to support the prostate gland
We have already discussed how the puboprostatic ligament supports the prostate gland Which muscle slings around the prostate gland to help support it?
The levator prostatae muscle - which is technically part of the levator ani slings around the prostate gland helping support it
The muscle outside the levator prostatae is the puborectalis which slings around the rectum helping maintain fecal continence
Where is the widest and narrowest parts of the urethra?
The widest part of the urethr is at the prostatic urethra The narrowest part of the urethra is as the urethra passes through the urogenital diaphragm - the membranous urethra
Why may an enlarged prostate affect micturition? What age group of males is prostatic hypertrophy commonly seen in?
If you have an enlarged prostate, it may be difficulty for the sphincter vesicae (involuntary and incomplete sphincter) to fully close around the neck of the bladder leading to problems with urination Prostatic hypertrophy is commonly seen in males aged > 50 years
What is the lymphatic drainage of the teste and epidiymis? What is the lymphatic drainage of the scrotum and skin below the umbilicus? What is the drainage of the prostate gland?
The testis and epididymis drain to the para-aortic nodes at root of testicular artery at L2
The scrotum and skin below the umbilicus drains to the superficial inguinal nodes
The prostate gland drains to the internal iliac nodes
What lies between the bladder and the pelvic floor? What sits behind the seminal vesicles?
Between the bladder and pelvic floor lies the prostate gland The rectum sits behind the seminal vesicle
What features join to form the diamond shape that encompasses the urogenital and anal triangle? What line is drawn between the two triangles? What structures pass through each triangle?
A line is drawn from pubic symphysis to ischial tuberosities, to coccyx
A line is then drawn between the two ischial tuberosities to divide the diamond shape into urogenital & anal triangle
- Anal triangle - rectum passes through to become anal canal
- Urogenital triangle - vagina &urethra pass through here
What are the contents of the ischioanal fossa?
Within the ischioanal fossa, we have the internal pudendal vessels and the pudendal nerve and these structures give branches to form the inferior rectal vessels and the inferior rectal nerve
We also have (a lot) of adipose tissue
What artery arises adjacent to the opening of the anal canal? What is the structure that forms a circle around the opening of the anal canal? It is the final structure preventing defecation
Adjacent to the opening of the anal canal within the ischioanal fossa is the inferior rectal artery which is a branch of the internal pudendal artery
The external anal sphincter is a circular structure enclosing the opening of the anal canal. As this is skeletal muscle it is under voluntary control
Where does the rectum begin and end? What are the two sphincters of the anal canal?
The rectum begins at the 3rd sacral vertebrae and ends 2cm in front of the tip of the coccyx as it pierces the pelvic floor to become the anal canal
The wall of anal canal is a smooth muscle involuntary sphincter - the internal anal sphincter
Sitting outside the wall of the anal canal is a skeletal muscle voluntary sphincter - the external anal sphincter
Can see the wall of the anal canal having the smooth muscle involuntary internal anal sphincter Can see outside the wall of the anal canal being the voluntary skeletal muscle forming the external anal sphincter What are the longitduinal ridges in the anal canal and what separated them?
The longitudinal ridges in the anal canal are anal columns which are separated by the anal sinuses
What artery do each of the anal columns contain? What innervates the external anal sphincter?
The anal columns contain a terminal radicle of the superior rectal arteries and veins
The external anal sphincter is innervated by the inferior rectal branch of the pudendal nerve - remember it is somatic and therefore needs a motor supply
What does the external anal sphincter attach to?
The external anal sphincter attaches to the coccyx via the anococcygeal ligament And it attaches to the perineal body
What is the line that marks the transition from the anal canal digestive mucosa to the skin?
This is the white line (anocutaneous line) - marks the trnasition from the non keratinized squamous epithelium to the keratinized squamous epithelium (skin)
Which levator ani muscle bbends some of its fibres with which part of the external anal sphincter to help maintain faecal continence? What are the three parts of the external anal sphincter?
The deep part of the external anal sphincter blends superiorly with the puborectalis which bends around the rectum to help maintain faecal continence
External anal sphincter - have the subcutaenous, superficial and deep parts
What is the arterial supply to the anal canal?
Above pectinate line
- Terminal radicle branches from the superior rectal artery which go to the anal columns (from inferior mesenteric artery)
Below pectinate line
- Inferior rectal arteries (from internal pudendal from internal iliac artery) Middle rectal artery forms anastamoses with both
What is the lymphatic drainage of the anal canal?
Above the pectinate line - drains back to the internal iliac nodes
Below the pectinate line - drains to the superficial inguinal nodes
What is the difference in nerve innervation to the anal canal?
Above the pectinate line - ANS nerve innervation from inferior hypogastric plexus
Below the pectinate line - Somatic motor and sensory nerve innervation from inferior rectal nerve branch of pudendal nerve
