Rectum Flashcards
where is the rectum located?
The rectum is the most distal segment of the large intestine
what is the role of the rectum?
temporary store of faeces
what is the rectum continuous with proximally?
It is continuous proximally with the sigmoid colon
where does the rectum terminate into?
terminates into the anal canal
approximately how long is the rectum?
15cm long
where does the rectum begin?
at the level of S3 (as a continuation of the sigmoid colon)
how is the rectum macroscopically distinct from the colon?
with an absence of taenia coli, haustra, and omental appendices
what are the 2 major flexures that mark the course of the rectum?
Sacral flexure
Anorectal flexure – .
what is the sacral flexure?
anteroposterior curve with concavity anteriorly
what is the anorectal flexure?
anteroposterior curve with convexity anteriorly
what does the sacral flexure follow?
follows the curve of the sacrum and coccyx
what forms the anorectal flexure?
formed by the tone of the puborectalis muscle, and contributes significantly to faecal continence
how many additional lateral flexures are there?
3 additional lateral flexures
what are the 3 additional lateral flexures?
superior, intermediate, inferior
what are the 3 additional lateral flexures formed by?
transverse folds of the internal rectum wall
what is the final segment of the rectum?
the ampulla
what happens when the ampulla relaxes?
relaxes to accumulate and temporarily store faeces until defecation occurs
what is the ampulla continuous with?
continuous with the anal canal
what does the anal canal pass through?
passes through the pelvic floor to end as the anus
in the superior third of the rectum, what covers the anterior surfaces and lateral sides?
covered by peritoneum
where does the peritoneum cover in the middle third of the rectum?
only has anterior peritoneal covering
is there peritoneum in the lower 1/3
no peritoneum associated with it
in males, what forms the rectovesical pouch?
the reflection of peritoneum from the rectum to the posterior bladder wall
in female, what forms the rectouterine pouch (pouch of Douglas)
the peritoneum reflects to the posterior vagina and cervix
where is the rectum located?
within the pelvic cavity
what is the rectum in terms of the pelvic viscera?
most posterior of the pelvic viscera
how is the anatomical relations of the rectum in males and females?
different anatomical relations
what is anterior to the rectum in males?
Rectovesical pouch Sigmoid colon Ileum Bladder Prostate Seminal vesicles
what is anterior to the female rectum?
Rectouterine pouch Sigmoid colon Ileum Vagina Cervix
what is posterior to the rectum in males and females?
Sacrum and coccyx Piriformis Coccygeus Levator ani Sacral plexus
