Week 7+8 Digestive System Flashcards
order of small intestine
duodenum
jejunum
ileum
________- of the small intestine mucosa slow the passage of food, thereby providing more time for digestion and absorption
Circular folds
folds for absorption are most numerous and prominent in the
jejunum and upper ileum.
Absorption occurs through
villi (jazz hands)
A villus is composed of
-absorptive columnar epithelial cells (enterocytes)
-mucus-secreting goblet cells
-Each villus secretes enzymes necessary for digestion and absorbs nutrients
___________ create a mucosal surface known as the brush border
microvilli
contains lymphocytes; plasma cells, which produce immunoglobulins; and macrophages.
lamina propria (a connective tissue layer of the mucosa) lies beneath the epithelial cells of the villi
if you are lactose intolerant youre deficient in
lactase
inhibits the breakdown of lactose (milk sugar) into monosaccharides glucose and galactose and therefore prevents lactose digestion and absorption across the intestinal wall.
lactase deficiency
lactase persistence (LP).
-most people stop making as much lactase after breast feeding
-most are completely done between 10-15 y/o
-but some still can make lactase and digest
are milk allergies and lactose intolerance different
yes
details of lactose intolerance
-undigested lactose remains in the intestine,
-bacterial fermentation causes gases to form.
-Undigested lactose also increases the osmotic gradient in the intestine, causing irritation and osmotic diarrhea.
lactose intolerance sxs
bloating, crampy pain, diarrhea, and flatulence
lactose intolerance tests
- Hydrogen breath test
- genetic testing
- food sensitivity testing
Gluten-sensitive enteropathy,
celiac disease
autoimmune disease of the small intestinal villous epithelium when there is ingestion of the cereal protein gluten (gliadin) found in wheat, rye, barley, and oats in genetically susceptible individuals
celiac disease
other autoimmune associated with celiac
type 1 diabetes mellitus, autoimmune thyroiditis, and Addison disease.
what cells infiltrate during celiac disease
T cells
flattening of villi in the upper small intestine happens in
celiac
malabsorption in celiac
loss of mucosal surface area and brush-border enzymes leads
Fat malabsorption in the jejunum is the major cause of
steatorrhea (fatty stools)
a cutaneous manifestation of gluten-sensitive enteropathy
Dermatitis herpetiformis
-blister formation on skin
-symettrical
-usually on elbows
most common GI condition
IBS
IBS classifcations
1.IBS with diarrhea (IBS-D), 2. IBS with constipation (IBS-C)
3. mixed IBS (IBS-M)
origins of IBS
- Microbiome alterations from early use of antibitoics
- post intestinal infection
- Visceral hypersensitivity in gut lumen
diet for IBS
low FODMAPS
-group of carbohydrates that are poorly absorbed in the small intestine and subsequently fermented in the small or large intestine
Inflammatory Bowel Diseases
-ulcerative colitis
-crohns
-genetic factors, alterations in epithelial cell barrier functions, immunopathology related to abnormal T-cell reactions to commensal microflora
a chronic inflammatory disease that causes ulceration of
the colonic mucosa and extends proximally from the rectum into the colon
ulcerative colitis
age for ulcerative colitis
20 and 40 years of age
The primary lesions of UC are continuous with no skip lesions, are limited to the mucosa, and are not transmural
The primary lesions of UC are continuous with no skip lesions, are limited to the mucosa, and are not transmural
where is UC most severe
rectum and sigmoid colon
complications of UC
toxic megacolon, anal fissures, hemorrhoids, and perirectal abscess
UC treatment
-5-aminosalicylic acid (mesalazine) (a type of NSAID)
-Corticosteroids and salicylates suppress the inflammatory response
-immune suppressants
-affects any part of the gastrointestinal tract from the mouth to the anus
-small intestine and proximal large colon are most commonly affected by the disease
Crohns Disease
most common site of Crohns
ileocolon
-but both the large and small intestines may be involved.
typical Crohns lession
-granuloma
-cobblestone projections of inflamed tissue surrounded by areas of ulceration
does CD or UC commonly have fistulas anal fissure, perianal abscess, and fistula
Chrons
-fistula= abnormal connection between organs because there is a degradation of tissue
-happens in Crohns where are layers of GI are eaten away
-UC is superficial ulceration
Crohns vs ulceravtive colitis
-Crohn’s =there are healthy parts of the intestine mixed in between inflamed areas. -Ulcerative colitis=is continuous inflammation of the colon and rectum
herniations or saclike outpouchings of mucosa through the muscle layers of the colon wall
Diverticula
is Diverticulosis cause symptoms or associated with inflammation
no
bstruction of the diverticulum sac by fecaliths, irritation of the mucosa that causes inflammation, congestion and further obstruction.
diverticulitis
diverticulitis sxs
abdominal pain (usually on the left side), fever, nausea, vomiting, cramps, and constipation.
inflammation of the vermiform appendix, which is a projection from the apex of the cecum
Appendicitis
most common surgical emergency of the abdomen and usually occurs between 20 and 30 years of age
Appendicitis
appendix pain
shift of location to the right lower quadrant with rebound tenderness.
most common internal hemorrhoids sxs
bleeding (painless)
are internal or external hemorrhoids more painful
external
-localized in mucosal layer
-no skip lesions
-only in colon
Ulcerative colitis
-transmural inflammation, (mucosa and serosa)
-cobblestone projections
-skip lessons (anywhere from mouth to anus but not continuous)
Crohns Disease
