Jejunum and Ileum Flashcards
Why are the jejunum and ileum mobile?
They are suspended from the posterior abdominal wall by the mesentery end
How much of the mobile small intestine is occupied by the jejunum?
Upper two-fifths
How much of the mobile small intestine is occupied by the ileum?
Lower three-fifths
Where does the jejunum begin?
Duodenojejunal flexure
Where does the ileum terminate?
Ileocecal junction
What five features cna be uised to distinguish between the jejunum and ileum?
Location
Walls
Lumen
Mesentery
Circular mucosal folds
Difference in location between jejunum and ileum
Jejunum: Occupies upper and left parts of intestinal area
Ileum: Occupies lower and right parts of intestinal area
Difference in walls of jejunum and ileum
Jejunum: Thicker, more vascular walls
Ileum: Thinner, less vascular walls
Difference in lumen of jejunum and ileum
Jejunum: Wider and more empty
Ileum: Narrower and often loaded
Difference in mesentery of jejunum and ileum
Jejunum:
Windows present
Fat less abundant
Arterial arcades, 1 or 2
Vasa recta longer and fewer
Ileum:
No windows
Fat more abundant
Arterial arcades, 3 or 6
Vasa recta shorter and more numerous
Difference in circular mucolar folds of jejunum and ileum
Jejunum: Larger and more closely set
Ileum: Smaller and sparse
What is Meckel’s Diverticulum?
The persistent proximal part of the vitellointestinal duct which is present in the embryo
Normally disappears during the 6th week of intrauterine life
Characteristics of Meckel’s Diverticulum
It occurs in 2% subjects
It is 2 inches or 5 cm long
Situated about 2 feet or 60 cm proximal to the ileocecal valve
Attached to antimesenteric border of the ileum
Calibre is equal to that of the ileum
Apex may be free or may be attached to the umbilicus, to the mesentery, or to any other abdominal structure by a fibrous band
