The cecum and appendix Flashcards
what is the cecum and appendix part of?
the gastrointestinal tract
where is the cecum and appendix located?
They are the most proximal part of the large intestine, located between the ileum (distal small bowel) and the ascending colon
what was the function of the cecum?
Having served as a site for cellulose digestion in our ancestors
what does the cecum now act as?
the cecum now simply acts as a reservoir for chyme which it receives from the ileum
what is chyme?
mass of partly digested food that is expelled by the stomach
what is the function of the appendix and what does it contain?
The appendix contains a large amount of lymphoid tissue, but has no vital functions in the human
what is the cecum? where can it be found?
the most proximal part of the large intestine and can be found in the right iliac fossa and suprapubic region
where does the cecum lie in relation to the iliocaecal junction?
It lies slightly inferior to the iliocaecal junction
where can the cecum be palpated? when can it be palpated?
in the right iliac fossa if enlarged due to faeces, gas or malignancy
what happens at the cecum inferiorly?
is a blind end
what happens at the cecum superiorly?
the open end of the cecum is continuous with the ascending colon
where is the cecum? what is it unlike?
Unlike the ascending colon above it, the cecum is intraperitoneal
what is the appendix also known as?
the vermiform (worm-shaped)
what is the appendix
appendix is a narrow, blind ended tube attached to the posteromedial end of the cecum
how is the position of the free-end of the appendix?
The position of the free-end of the appendix is highly variable, and can be categorised into seven main locations
what is the most common positions of the free-end of the appendix?
The most common positions are retrocaecal and subileal
what is a simple way to remember the positions of the appendix?
as the hour hand of a clock
what is the pre-ileal position of the appendix? where is it at?
Anterior to the terminal ileum – 1 o’clock
what is the post-ileal position of the appendix? where is it at?
Posterior to the terminal ileum – 2 o’clock
what is the sub-ileal position of the appendix? where is it at?
Parallel with the terminal ileum – 3 o’clock
what is the pelvic position of the appendix? where is it at?
Pelvic – Descending over the pelvic brim – 5 o’clock
what is the sub-caecal position of the appendix? where is it?
Below the cecum – 6 o’clock
what is the paracaecal position of the appendix? where is it?
Alongside the lateral border of the cecum – 10 o’clock
what is the retrocaecal position of the appendix? where is it?
Retrocaecal – Behind the cecum – 11 o’clock
where is the cecum derived from embryologically?
The cecum is derived from the embryologic midgut
where is the blood supply of the cecum from?
by a branch of the superior mesenteric artery
which branch of the superior mesenteric artery supplies the cecum?
ileocolic artery
what happens to the ileocolic artery in order to supply the cecum?
splits into anterior and posterior caecal arteries to supply the cecum
where does the venous drainage for the cecum come from?
ileocolic vein
where does the ileocolic vein drain into?
superior mesenteric vein
where does the appendix receives its blood supply via?
appendicular artery
where is the appendicular artery derived from?
ileocolic artery
what does the appendix drain through?
appendicular vein
where is the appendicular artery and vein contained? what are they contained with?
Both are contained, along with lymphatic vessels and nerves, within the mesoappendix
what is the mesoappendix?
a fold of mesentery which suspends the appendix from the terminal ileum
what innervates the cecum and appendix?
The autonomic nervous system
how does the ANS innervate the cecum and appendix?
by means of the ileocolic branch of the superior mesenteric plexus
what course of travel does the ileocolic branch of the superiro mesenteric plexus follow?
the same course as the ileocolic artery
where does lymph from the cecum and appendix drain into?
ultimately drains into the upper and lower ileocolic lymph nodes, which surround the ileocolic artery
what does upper and lower ileocolic lymph nodes surround?
ileocolic artery
where does lymph from the cecum travel via?
lymph from the cecum travels via a number of intermediate mesenteric nodes
where does lymph from the appendix travel?
via a single intermediate node in the mesoappendix.
