Male pelvic contents and anal triangle Flashcards
What is the blood supply to the rectum?
- Superior rectal (from inferior mesenteric)
- Middle rectal (from internal iliac)
- Inferior rectal (from internal pudendal)
Which muscle aids the external anal sphincter in the control of defecation?
The Puborectalis
Bends the rectum to slow the passage of faeces and helps maintain continence
What is the main component of the ischioanal fossae and what is the importance of this?
Adipose tissue/fat
Supports the neurovascular structures
Allows the anal canal space in which it can expand into during the expulsion of faeces from the body
True or False?
Both of the anal sphincters are under voluntary control
False!
The internal anal sphincter is formed by the wall of the anal canal and is under involuntary control
The skeletal muscle that surrounds the opening of the anal canal forms the external anal sphincter which is under voluntary control
When does the rectum become the anal canal?
When it pierces the pelvic floor in the anal triangle
What is the role of the prostate gland?
Releases fluid that increases the liquid component of semen and helps support the sperm
The fluid is alkaline so helps to neutralise the acidic environment of the vagina
Why might hypertrophy of the prostate gland cause urinary problems?
Enlargement of the gland can affect the passage of urine from the bladder - patients may experience leakage of urine or the desire to urinate
If lobes increase in size they can compress or distort the urethra which can cause problems releasing urine
Can lead to the formation of pouches in the bladder that urine can pool in, increasing the likelihood of UTIs
What is highlighted in the image?
Ischioanal fossae
What arteries supply the prostate?
Internal pudendal
Middle rectal
Inferior vesical arteries
What is the relationship of the internal rectal plexus and the internal anal sphincter?
The plexus sits superficial to the internal anal sphincter
Describe the journey of the vas deferens towards the pelvis
Cross the lateral wall of the pelvis over the external iliac vessels to descend towards the seminal vesicles
What is highlighted in this image?
Seminal vesicle
What nerve controls external anal sphincter?
Pudendal nerve (S2-4) - inferior rectal branch
What does this image show?
Anal columns
What makes up the borders of the ischioanal fossae?
Walls- ischial tuberosity, rectum/anal canal
Roof- levator ani muscle
Floor- skin
What is the innervation of the external anal sphincter?
The inferior rectal nerve - a branch of the pudendal nerve
What is the name of the spaces found on either side of the rectum?
The ischioanal (ischiorectal) fossae
Which structures does the external anal sphincter pass between to wrap around the opening of the anal canal?
Anococcygeal ligament Perineal body (a dense structure of connective tissue that lies at the edge of the urogenital diaphragm to provide attachment to the muscles of the perineum)
What is highlighted by this image?
The Pectinate line