1. ANATOMY
The
colon starts in the right lower
abdomen and completes its
course
as an inverted C to end in the left lower abdomen.
The
further course is in the pelvis (pelvic colon) and
continues as
the rectum and anal canal.
1.1 ARTERIES + LYMPHNODES
The
cecum, colon rectum and pronimal anal canal receive
their
arterial supply from branches of
superior and inferior mesenteric
arteries, both are branches of the
aorta (fig 19.1) anastomosis
between the
branches from a
continuous marginal artery
of
drummond the distribution of lymph
glands is shown in fig 19.2.
1.2 CECUM
This
is the first part of the large intestines and Ileum end in
it.
There is an ileacecal muscular
valve to prevent flow of
local contents into the ileim. The diameter of the cecum is 7-9
cms.
The appendix is placed at the medial posterior aspect
of
the cecum.
Colon
Motility of the colon is aimed at providing maximum
contact to the chyme (500-1500 per day) to the absorptive colon mucosa the final
residue of 50-100cc the proximal part of colon provides surface for absorption
of water and the distal half storage of fecus the motility is segmentation and
bag like haustration.
Mass movement is a modified prostates that occurs 15
minutes after morning breaking fast. These mass movements in the colon occur as
a result of gastro colic and duodenal colic reflex.
Colonic irritation can also cause mass movement this
is seen in case of ulcerative colitis.
1.3 ASCENDING COLON
It
extends upwards from the cecum to reach the under surface of
the
liver here it bends (Hepatic flexure) to course transversly
access the upper abdomen as the
Transverse colon.
1.4 TRANSVERSE COLON
This part of the colon starts at the
hepatic flexure and ends at
the splenic flexure in the left upper
abdomen. It measures 35 to
50
cms. in length. It is a mobile
portion of the colon and is
immobile at the hepatic and splenic
flesures.
1.5 DESCENDING COLON
Proceeds downwards from the splenic flexure, measures
20-25 cms
to end in the pelvic colon.
1.6 PELVIC COLON
It
is also called the sigmoid colon it is curved in the form of
an
S and its length is variable from 10-30 cms. it ends in the
upper part of the rectum
Any questions be sent to drmmkapur@gmail.com
All older posts are stored in archives for access & review.
Visitors that follow may post contributions to the site,please write to address above.
To create consumer/provider engagement visit www.drmmkapur.blogspot.com
