Large Intestine Flashcards
Talk briefly about Teniae coli (their arrangement-Numnber)
3 longitudinal muscle bands.
They are arranged one
anterior & two posterior in ascending and descending colon
In transverse colon they are two anterior & one posterior
Teniae coli are absent in?
appendix & rectum
Appendices epiploicae or omental appendices are absent in?
absent in caecum, appendix & rectum
Define ceacum, length, location
It is a blind-ended sac, 3 inches long, situated in right iliac fossa
Vermiform appendix is attached to the ceacum to its?
posteromedial surface
Ileocecal orifice is provided with …?
two lips, which forms its ileocecal valve
Blood Supply Of The Cecum (Mention their branches)
▪ Arteries: Anterior & posterior cecal arteries form ileocolic artery (branch of superior mesenteric artery)
▪ Veins: Drain into superior mesenteric vein
▪ Lymph drainage: Superior mesenteric nodes
▪ Nerve Supply: from superior mesenteric plexus
Describe the Vermiform appendix structure, where does it lie, length
It is a narrow, worm-like muscular tube containing a large amount of lymphoid tissue, lies in the right iliac fossa
Vermifrom appendix base opens in the
posteromedial surface of cecum about 1 inch below ileocecal junction
Does the Vermifrom appendix have a peritoneum covering it?
It has a complete peritoneal covering (mesoappendix) that contains appendicular vessels, nerves, lymphatics & lymph nodes
Blood supply of the appendix
▪ Arteries: appendicular artery (branch of ileocolic artery)
▪ Veins: appendicular vein drains into ileocolic vein
▪ Lymphatics: Superior mesenteric nodes
What are the Common Positions Of Appendix in order
- Retrocecal position (65%): it lies behind cecum.
- Pelvic position (31%): descending down into pelvis.
- Subcecal position (2%): projecting just below cecum.
- Pre-ileal position (1.5%): in front Subcecal of the terminal part of ileum.
- Retro-ileal position (0.5%): behind the terminal part of ileum
Describe the Surface anatomy of the appendix
The base of the appendix is situated at (McBurney’s point) the point of junction of the lateral 1/3 & medial 2/3 between the right anterior superior iliac spine with the umbilicus
McBurney’s point is known to be
It’s the point of maximum tenderness in acute
appendicitis
Pain of the appendicitis may be referred to the? why?
umbilicus as they are supplied by the same T10
What might be injured during the appendectomy
Iliohypogastric & Ilioinguinal nerves
Ascending colon lies in? Extends from where to where?
It lies in right lumbar region and extends upward from the ileocecal valve to inferior surface of right lobe of liver, where it turns to the left, forming right colic flexure
Ascending colon length
15 cm long
Is the ascending colon covered by peritoneum?
It is covered by peritoneum from the front and sides only
Blood supply of the ascending colon
1- Arteries: ileocolic & right colic branches of superior mesenteric artery
2- Veins: ileocolic & right colic veins drain into superior mesenteric vein
3- Lymph Drainage: Superior mesenteric lymph nodes
4- Nerve Supply: Superior mesenteric plexus
Transverse colon passes from which regions, length
right hypochondriac region into left hypochondriac region, 50 cm long
Transverse colon extends from where to where?
Extends from right colic flexure below the liver to left colic flexure below the spleen
Describe the left colic flexure and right colic flexure position
The left colic flexure is higher (L1) and more posterior than the right colic flexure (L2)
What is the Transverse mesocolon
suspends the transverse colon from the anterior border of pancreas
Blood supply of the Transverse Colon
Arteries:
1. Right 2/3: mainly by middle colic artery (superior mesenteric artery)
2. Left 1/3: by left colic artery (inferior mesenteric artery)
▪ Veins: Superior and inferior mesenteric artery
▪ Lymph drainage: Right 2/3 into superior mesenteric nodes; left 1/3 into inferior mesenteric nodes.
▪ Nerve supply: right 2/3 by superior mesenteric plexus; left 1/3 through inferior mesenteric plexus.
Descending colon extends from … to …
extends downward from left colic flexure, to pelvic brim, where it becomes continuous with sigmoid colon
Length of Descending colon
25 cm long
Is the Descending colon retroperitoneal or intraperitoneal
Peritoneum covers its front & sides for that it’s retro
Descending colon blood supply
- Arteries: left colic and sigmoid branches of inferior mesenteric artery
- Veins: drain into inferior mesenteric vein.
- Lymph drainage: inferior mesenteric nodes
- Nerve supply: from inferior mesenteric plexus
Sigmoid colon lies in? How many cm long is it? Describe it’s shape? Is it intra or retro peritoneal
It lies in the left iliac fossa & pelvic cavity
About 40-50 cm long
It is S-shaped & completely surrounded by peritoneum
Sigmoid colon becomes continuous with?
continuous with the rectum at the level of S3
vertebra
Sigmoid colon peritoneum shape and name?
Sigmoid colon has a fan shaped fold of peritoneum, known as sigmoid mesocolon
Sigmoid colon blood supply
- Arteries: Sigmoid branches of the inferior mesenteric artery
- Veins: Drains into sigmoid veins then to the inferior mesenteric vein.
- Lymph drainage: Drains into the inferior mesenteric lymph nodes
- Nerve supply: From the Inferior hypogastric plexus
