Lec 7 Small Intestine Path

Question 1

What are peyers patches?

Answer 1

large lymphoid aggregates in terminal ileum; site of bile salt and vit B12 absorption

Question 2

What is meckel’s diverticulum?

Answer 2

persistent vitelline duct

can contain heterotopic gastric or pancreatic tissue

Question 3

What are the five 2s of meckels?

Answer 3

• 2 inches long
• 2 feet from ileocecal valve
• 2% of population
• presents in first 2 years of life
• 2 types of epithelium may be present [gastric/pancreatic]

Question 4

What is major complication of meckel’s?

Answer 4

acid secreted by gastric tissue in meckels can irritate adjacent intestinal mucosa and cause peptic ulceration, bleeding, appendicitis-like symptoms

Question 5

What are features of small intestine that predispose it to extrinsic obstruction?

Answer 5

• narrow lumen
• pliant wall
• long length
• mesenteric attachment

Question 6

What are 3 common causes of intestinal obstruction?

Answer 6

• hernia
• intussusception
• volvulus

Question 7

What are most common sites of hernia?

Answer 7

inguinal canal, femoral canal, umbilicus

Question 8

What is pathophys of hernia?

Answer 8

loop of bowel enters hernia sac but is reducible –> pressure on wall of mesentery compromises venous blood flow which makes the herniated tissue entrapped = encarcerated –> further pressure causes arterial compromise –> infarction = strangulated

Question 9

What is volvulus?

Answer 9

twisting of a loop of intestine about its mesentery –> causing obstruction and vascular compromise

Question 10

What are predisposing factors for volvulus?

Answer 10

• adhesions
• poor intestinal motility
• abnormal mesentery
• congenital malrotation

Question 11

What are adhesions?

Answer 11

fibrous bands connecting loops of bowel to each other or to other structs

usually caused by previous surgery, infection

Question 12

What is intussusception?

Answer 12

upstream bowel segment invaginates into downstream segment

begins when mass of bowel gets caught in downstream segment during peristalsis

causes luminal obstruction –> segmental infarction

Question 13

What is major cause of intussusception in adults?kids? treatment for each?

Answer 13

adults = usually due to tumor; treat by surgery

kids = usually due to hyperplastic lymphoid tissue; treat = retrograde barium enema

Question 14

What are symptoms of celiac

Answer 14

• steatorrhea
• failure to thrive
• short stature
• Ca malabsorption, osteoporosis
• iron deficiency anemia
• infertility

Question 15

What are some diseases associated with celiac?

Answer 15

• T cell lymphoma
• dermatitis herpetiformis
• GI and non GI cancers
• ulcerative jejunoilieitis
• collagenous sprue

Question 16

What is a collagenous sprue?

Answer 16

collagen depositing right under surface

Question 17

What is congenital lymphangiectasia?

Answer 17

• rare genetic disorder –> have malformations of lymphatic system

mutation in VEGFR-3

Question 18

What are signs of congenital lymphangiectasia?

Answer 18

• asymmetrical edema
• chylous ascites
• engorged lacteals

malnutrition, recurrent infections

Question 19

What are some diseases that cause impaired lymphatic drainage in intestines?

Answer 19

• congenital lymphangiectasia
• whipple’s disease
• lymphoma
• TB

Question 20

How does ZE syndrome effect digestion/absorption?

Answer 20

too much acid –> lipase not activated b/c duodenum too acidic –> impaired digestion of fats

Question 21

What is effect of acquired small intestinal diverticula?

Answer 21

cause bacterial overgrowth
- usually in elderly patients –> diverticula produced by hernieation of mucosa through wall of intestine at points of entry of blood vessels and nerves

leads to stagnation of intestinal contents and bacterial overgrowth