Jejunum and Ileum

Question 1

Describe the jejunum.

Answer 1

• makes up the proximal 2/5 of the small intestine, distal to the duodenum - it begins at the duodenojejunal flexure and lies mostly in the left upper quadrant of the abdomen - segment of the gut that is most involved with nutrient uptake or absorption

Question 2

Describe the ileum.

Answer 2

• makes up the distal 3/5 of the small intestine - occupies the right lower quadrant of the abdomen, and joins the cecum at the ileocecal junction - absorbs fat soluble vitamins, vitamin B12, and bile salts

Question 3

What are the jejunum and ileum suspended by?

Answer 3

they are both suspended from the posterior abdominal wall by the mesentery, which carries blood vessels, nerves and lymphatics to them

Question 4

What is the vasa recta?

Answer 4

the straight terminal branches of the arteries which travel through the mesentery to supply the small intestine

Question 5

What are the plica circulares?

Answer 5

circular folds found within the small intestine that increase the surface area for digestion

Question 6

What are Peyer’s patches?

Answer 6

• aggregations of lymphoid tissue found within the walls of the small intestine - immune defense of the alimentary canal

Question 7

Contrast between the jejunum and ileum.

Answer 7

Question 8

What is the blood supply to the jejunum and ileum?

Answer 8

Jejunal and ileal branches of the superior mesenteric artery

Question 9

What is the innervation of the jejunum and ileum?

Answer 9

Autonomic fibers from the superior mesenteric plexus

Question 10

What are ileal (Meckel’s) diverticulum?

Answer 10

• a common malformation of the digestive tract
• remnant of a portion of the embryonic vitelline duct
• a fingerlike pouch which projects from the distal ileum
• contains all layers of the ileum and may contain gastric or pancreatic tissue
• gastric tissue may secrete acid
• the diverticulum often becomes inflammed, mimicking appendicitis

Question 11

What is Crohn’s disease?

Answer 11

• an inflammatory bowel disease which most commonly affects the distal ileum and adjacent colon, but can affect any part of the digestive tract
• affects all layers of the intestine and results in thickening and ulceration of the affected segment
• results in pain, diarrhea, and malabsorption
• etiology is unknown
• produces a “cobblestone” radiographic appearance

Question 12

What is the chiropractic note associated with motility of the small intestine?

Answer 12

• motility of the small intestine is controlled, in part, by the ANS (vagus, greater and lesser splanchnic nerves)
• subluxations of lower thoracics may affect motility, contributing to conditions such as Crohn’s disease