digestive tract part 2

Question 1

what makes up the proximal 2/5 of the small intestine?

Answer 1

jejunum

Question 2

what makes up the distal 3/5 of the small intestine?

Answer 2

ileum

Question 3

which segment is most involved in nutrient absorption?

Answer 3

jejunum

Question 4

which segment absorbs fat soluble vitamins, B12 and bile salts?

Answer 4

ileum

Question 5

what was an old weight loss procedure that resulted in explosive diarrhea?

Answer 5

jejunoileal bypass

Question 6

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

Answer 6

vasa recta

Question 7

what are the circular folds found within the small intestine

Answer 7

plicae circulares- increase surface area, slow passage of material

Question 8

what are aggregations of lymphoid tissue found within the walls of the small intestine?

Answer 8

peyer’s patches- immune defense

Question 9

what is the blood supply to the ileum and jejunum?

Answer 9

superior mesenteric artery

Question 10

what is the innervation of the jejunum and ileum?

Answer 10

autonomic fibers from the superior mesenteric plexus

Question 11

what is a common malformation of digestive tract with a remnant portion of embryonic vitelline duct?

Answer 11

ileal (meckel’s) diverticulum- fingerlike pouch which projects from the distal ileum

diverticulum gets inflamed mimicking appendicitis

Question 12

what is an autoimmune inflammatory bowel disease which usually affects the distal ileum and adjacent colon?

Answer 12

crohn’s disease

Question 13

crohn’s disease results in thickening and ulceration of affected segment and has what symptoms?

Answer 13

pain, diarrhea, malabsorption

Question 14

what is the length of the large intestine?

Answer 14

extends from ileocecal junction of anus and is 1.5 m in length

Question 15

what is the LI primary function?

Answer 15

convert liquid contents of ileum into semisolid feces by absorbing water

also involved in synthesis of some vitamins- K

Question 16

what prevents back flow of feces into ileum?

Answer 16

ileal fold

Question 17

what are the 4 parts of the LI?

Answer 17

cecum
-ileal fold
appendix 
colon 
rectum and anal canal

Question 18

what attaches the appendix to the mesentery of the ileum?

Answer 18

mesoappendix

Question 19

what is the most common position of the appendix?

Answer 19

retrocecal

Question 20

what is the most common intra-abdominal inflammatory condition which involves inflammation of the reniform appendix?

Answer 20

appendicitis

Question 21

what is the cause of appendicitis?

Answer 21

obstruction of lumen due to:
fecal impaction
lymphoid hyperplasia

Question 22

what are 3 narrow longitudinal bands of muscle seen most prominently in the cecum and ascending colon?

Answer 22

taeniae coli

Question 23

what are sacculations of outpouchings of the colon?

Answer 23

haustra of colon

Question 24

what are small masses of fat which are covered with visceral peritoneum and which extend from colon?

Answer 24

omental appendices

Question 25

what are herniations of the mucosa of the colon through the muscular layer without inflammation

Answer 25

diverticulosis

Question 26

where and at what age are diverticulosis most common?

Answer 26

over age 40 and the sigmoid colon related to low fiber diet

Question 27

if the diverticuli become inflamed the condition is called?

Answer 27

diverticulitis

Question 28

how may diverticulosis be treated?

Answer 28

laser endoscopy

Question 29

what is an auto immune condition that results in sever inflammation and ulceration of the rectum and lower colon that is usually restricted to the mucosa?

Answer 29

ulcerative colitis

Question 30

what are symptoms of ulcerative colitis?

Answer 30

abdominal pain and diarrhea, bowel perforation may occur

Question 31

what is a key characteristic of ulcerative colitis?

Answer 31

tear drop deformity

Question 32

what is the blood supply to the small and large intestine?

Answer 32

superior mesenteric artery- large distribution inferior mesenteric artery marginal artery

Question 33

what are the branches of the superior mesenteric artery?

Answer 33

``` Inferior pancreaticoduodenal artery jejunal and ileal arteries- 12-15 branches ileocolic artery right colic artery middle colic artery ```

Question 34

what provides collateral circulation to colon and prevents a bowel infarction? also endpoint of ischemic bowel disease

Answer 34

marginal artery

Question 35

what is the mortality rate of transmural bowel infarction?

Answer 35

95%

Question 36

what are the branches of the inferior mesenteric artery?

Answer 36

left colic- descending colon sigmoid arteries- sigmoid colon superior rectal- terminal branch

Question 37

where do all branches of superior and inferior mesenteric arteries empty into?

Answer 37

marginal artery

Question 38

what is the straight terminal branch from marginal artery to LI?

Answer 38

vasa recta

Question 39

what is associated with increased risk of hiatal hernia, inguinal hernia, diverticulosis and colon cancer?

Answer 39

chronic constipation