Test 3 Flashcards
(257 cards)
in the GI system, what is the breakdown of food and fluids facilitated by?
general
enzyme
majority of molecular absorption into cells occurs where?
general
small intestine
what are the 5 roles of the GI system?
- mechanical processing and movement
- secretion
- digestion
- absorption of nutrients
- elimination
what are the accessory organs of the GI system?
- salivary glands
- liver
- gallbladder
- pancreas
the pancreas produces and secretes what two things?
general
enzymes
bicarbonate - neutralize stomach contents
identify and describe the layers of the GI system from innermost to outermost
- innermost - mucosa - epithelial cells in direct contact with the lumen
- submucosa - connective tissue containing blood vessels, lymph vessels and nerves
- muscularis - smooth muscle responsible for movement and motility
- outermost - serosa - connective tissue that provides anchorage of GI structures
what layer of the GI system contains the lamina propria?
mucosa
what layer of the GI system contains the peritoneum?
serosa
what are the 5 main GI hormones?
- gastrin
- cck - cholecystokinin
- secretin
- gip - gastric inhibitory peptide
- ghrelin
describe gastrin:
* secreted by
* secretion trigger
* what it causes
- secreted by mucosal cells in stomach
- secreted in response to stomach distrention or partially digested substances
- causes increased gastric motility and relaxation of pyloric and ileocecal sphincters (promote stomach emptying)
describe CCK:
* secreted by
* secretion trigger
* what it causes
- secreted by jejunum
- secreted in response to fat
- causes contraction of gallbladder and pancreatic secretions
describe secretin:
* what it causes
- neutralizes gastric secretions
describe GIP:
* secreted by
* secretion trigger
- secreted by upper portion of small intestine
- secreted in response to fat in chyme and carbohydrates
describe ghrelin:
* secreted by
* secretion trigger
* what it is counteracted by
- secreted by stomach
- increases appetite, stimulates GH secretion, produces weight gain
- counteracted by leptin
what are the 3 physiological characteristics of movement through the GI system?
- peristalsis - progressive movement that propels material forwards
- segmental contractions - to keep contents constantly moving and facilitate mechanical breakdown
- sphincters - rings that separate sections to promote one way movement
identify and describe the defense mechanisms of the GI system
- mucous - move pathogens and prevent direct contact with epithelial layers
- muscular layer and peristalsis - move items down and prevent pathogens from stopping and invading
- stomach acidity - antimicrobial effects to prevent tract colonization
- GI bile - create a hostile environment
- microbiome - add a protective layer, compete for nutrient resources, produce helpful components (i.e. vit K - coagulation)
- GALT - adaptive response
define dysphagia
difficulty swallowing
define gastritis
inflammation of the stomach lining
define gastroenteritis
inflammation along the GI tract
define enteritis
inflammation of the colon and small intestine
define enterocolitis
inflammation of the colon and small intestine
define colitis
inflammation fo the colon
define hemmorhagic colitis
bloody diarrhea
describe constipation by:
* definition
* causes
* complications
* preventative things
- definition: small, infrequent, or difficult bowel movments, less than 3 times a week
- causes: low fiber, lack of exercise, aging (slowed peristalsis), motility impacting conditions (diverticulitis, obstruction)
- complication: fecal impaction
- preventative thing: cellulose