Large Intestines, Rectum and Anal Canal Flashcards
At what level does the Rectum begin?
S 3
Fill in the blanks. In the rectum , there are three sickle-shaped transverse rectal folds, formerly called _____.
Rectal Valves of Houston
Which rectal valve is the largest?
Middle rectal valve
How long is the rectum?
12 cm long ( 5 inches)
What is the blood supply of the Rectum?
Superior rectal artery
Middle rectal artery
Inferior rectal artery
Median sacral artery
True or False? All of the rectum is covered in Peritoneum .
FALSE!! The Lower 1/3 of the rectum is not covered in Peritoneum
Where does the rectum begin and end?
1)Commences at Rectosigmoid junction anterior to the body of S3.
2) Ends about 2-3 cm in front and slightly below the tip of the coccyx as it passes through the pelvic diaphragm.
What is the name of the lower extent of peritoneum in males and where is it located ?
Pouch of Proust - 7.5 cm from the anus
What is the name of the lower extent of peritoneum in females and where is it located ?
( Rectouterine pouch of Douglas ) is about 5.5 cm above the anus or 7.5 cm above the external orifice of the Vagina.
Where does the middle curve of Rectum occur?
It occurs at the upper border of the coccyx.
What are the HORIZONTAL / TRANSVERSE RECTAL VALVES OF HOUSTON made of?
Mucosa, submucosa and a thickening of the inner circular muscle.
How long is the anal canal?
About 2.5 to 5.0 cm – usually around 3.8 cm in length*.
What is the name of the structure at the ends the anal sinuses?
Anal glands ( of Ball )
What is the name of the structure which the iliocaecal junction is guarded by?
Iliocaecal valve - whose almost transverse lips may help to prevent some reflux into the ileum,
Where is the caecum normally found?
The caecum lies on the peritoneal floor of the right iliac fossa, over the iliacus and psoas fasciae and the femoral and lateral femoral cutaneous nerves. Its lower end lies at the pelvic brim.
What is the blood supply of the caecum?
Branches of the anterior and posterior caecal arteries which fan out over the respective surfaces of the caecum.
What is the anterior and posterior caecal arteries a branch of?
Ileocolic artery
What is the length of the normal appendix?
6–9cm
What is the most common position of the appendix?
Retrocoecal position- behind the cecum
What is the name of the small fold of peritoneum which extends from the terminal ileum to the front of the mesoappendix?
Inferior ileocaecal fold (or ‘bloodless fold of Treves’)
What is the name of the space between the Ileocaecal fold and the meso appendix?
Inferior ileocaecal recess
What is the blood supply to the Appendix?
The appendicular artery is normally a branch of the inferior division of the ileocolic artery (lodenquai says posterior caecal artery)
Fill in the blanks. “Exposure of the appendix during appendicectomy is through a _____________.”
McBurney or transverse muscle-splitting incision
Which parts of the large intestines are suspended in mesenteries?
The transverse colon and sigmoid colon.
How long is the Ascending Colon and where does it extend from?
15 cm - It extends upwards from the ileocaecal junction to the right colic (hepatic) flexure.
Where is the Caecum developed from?
From the caecal bud arising from the caudal limb of the primitive intestinal loop
How long is the Transverse colon?
50 cm long
How long is the descending colon?
25cm
Where is the splenic flexure located?
The splenic flexure lies on the lateral surface of the left kidney, below and in contact with the tail of the pancreas and the spleen.
Where is the phrenicocolic ligament located and what structures does it connect to?
It attaches the splenic flexure to the diaphragm at the level of the tenth and eleventh ribs.
Mobilization of the descending colon is conveniently carried out by dividing the peritoneum along what structure?
White line of Toldts
Where is the weakest link in marginal chain of vessels?
It is near the left colic flexure, between the middle and left colic branches, i.e. between midgut and hindgut vessels.
What is the blood supply to the colon?
The ascending colon and the proximal two-thirds of the transverse colon are supplied by the ileocolic, right colic and middle colic branches of the superior mesenteric artery, and the remainder of the colon by the left colic and sigmoid branches of the inferior mesenteric.
What is the nerve supply for the large intestines?
Parasympathetic supply- partly from the vagi and partly from the pelvic splanchnic nerves.
Sympathetic supply - derived from spinal cord segments T10–L2.
What are the three components of Tinaei Coli?
Teniae libera - ( Anterior)
Teniae Mesocolica - (Posteromedial)
Teniae Omentalis - (Posterolateral)
What is Lemmel’s syndrome ?
Lemmel syndrome is a rare clinical entity characterized by the presence of a periampullary duodenal diverticulum resulting in compression and dilatation of the pancreatic and common bile ducts, accompanied by obstructive jaundice.
Where does the root of the mesentery (of the small intestine) extend from?
The root of proper mesentery extends 15 cm from duodenojejunal flexure at the level of left side of L2, obliquely (toward inferior right) to the ileocecal junction in the right iliac fossa at the level of right sacroiliac joint.
What is the name of the lower dilated portion of the rectum?
Rectal Ampulla
What planes are the rectum present in ?
Anteroposterior and lateral planes
To what structures does the concavity of the Sacral curvature corresponds to?
The concavity of the sacrum and coccyx.
To what structures does the perineal curvature corresponds?
Corresponds to the forward bend of the anorectal junction.
Which lateral curvature of the rectum is convex to the left ?
Middle lateral curvature