Lec 7 Small Intestine Path Flashcards
What are peyers patches?
large lymphoid aggregates in terminal ileum; site of bile salt and vit B12 absorption
What is meckel’s diverticulum?
persistent vitelline duct
can contain heterotopic gastric or pancreatic tissue
What are the five 2s of meckels?
- 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]
What is major complication of meckel’s?
acid secreted by gastric tissue in meckels can irritate adjacent intestinal mucosa and cause peptic ulceration, bleeding, appendicitis-like symptoms
What are features of small intestine that predispose it to extrinsic obstruction?
- narrow lumen
- pliant wall
- long length
- mesenteric attachment
What are 3 common causes of intestinal obstruction?
- hernia
- intussusception
- volvulus
What are most common sites of hernia?
inguinal canal, femoral canal, umbilicus
What is pathophys of hernia?
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
What is volvulus?
twisting of a loop of intestine about its mesentery –> causing obstruction and vascular compromise
What are predisposing factors for volvulus?
- adhesions
- poor intestinal motility
- abnormal mesentery
- congenital malrotation
What are adhesions?
fibrous bands connecting loops of bowel to each other or to other structs
usually caused by previous surgery, infection
What is intussusception?
upstream bowel segment invaginates into downstream segment
begins when mass of bowel gets caught in downstream segment during peristalsis
causes luminal obstruction –> segmental infarction
What is major cause of intussusception in adults?kids? treatment for each?
adults = usually due to tumor; treat by surgery
kids = usually due to hyperplastic lymphoid tissue; treat = retrograde barium enema
What are symptoms of celiac
- steatorrhea
- failure to thrive
- short stature
- Ca malabsorption, osteoporosis
- iron deficiency anemia
- infertility
What are some diseases associated with celiac?
- T cell lymphoma
- dermatitis herpetiformis
- GI and non GI cancers
- ulcerative jejunoilieitis
- collagenous sprue
What is a collagenous sprue?
collagen depositing right under surface
What is congenital lymphangiectasia?
- rare genetic disorder –> have malformations of lymphatic system
mutation in VEGFR-3
What are signs of congenital lymphangiectasia?
- asymmetrical edema
- chylous ascites
- engorged lacteals
malnutrition, recurrent infections
What are some diseases that cause impaired lymphatic drainage in intestines?
- congenital lymphangiectasia
- whipple’s disease
- lymphoma
- TB
How does ZE syndrome effect digestion/absorption?
too much acid –> lipase not activated b/c duodenum too acidic –> impaired digestion of fats
What is effect of acquired small intestinal diverticula?
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
