Rectum Flashcards
The rectum arises from what sacral level?
3rd sacral vertebra
The peritoneum covers what surfaces of the rectum
Anterior and lateral surfaces
Valves present in the rectum
Valves of Houston
What structures are anterior of the rectum in females?
- Sigmoid colon
- Coils of ileum
- Vagina
What structures are anterior of the rectum in males?
- Sigmoid colon
- Coils of ileum
- UB
- vas deferens
- Seminal vesicles
- prostate
The superior rectal artery is a branch of ____
IMA
The middle rectal artery is a branch of the ___
Internal iliac
The inferior rectal artery is a branch of the
internal pudendal to internal iliac
The U-shaped sling that marks the start of the anal canal
Puborectalis
[Rectum]
Upper 1/3 arterial supply is a branch of
IMA
[Rectum]
the middle 1/3 arterial supply
Internal Iliac
[Rectum]
The lower 1/3 arterial supply is a branch of
Internal pudendal
[Rectum]
The upper 1/3 lymphatic drain to the ___
inferior mesenteric LN
[Rectum]
the middle and inferior 2/3 LN drain to the
Internal iliac LN
The anal canal is guarded by 2 sphincters. The external anal sphincter is made of ___ muscles
3 striated voluntary muscles
What separates the anal canal into 2 segments
dentate line
each has a different embryonic origin
[Embryology of the anal canal]
the upper part is derived from what embryonic layer?
Hindgut endoderm; columnar epithelium
sensitive to stretch with anal columns
[Embryology of the anal canal]
the lower part of the anal canal is derived from?
Ectoderm
stratified squamous
sensitive to pain, temperature and touch
What marks the start of the anatomic canal?
dentate line
ends at the anal verge
What marks the start of the surgical anal canal?
anorectal ring or junction and ends at the anal verve
Hemorrhoids can be palpated in what areas in the anus?
- Left lateral
- Right anterior
- Right posterior
what is the rule of 2 in meckel diverticulum
2 feet from the ileocecal junction
2% of the population
2 inches long
