Digestive system 1 Flashcards
What are the two main jobs of the GI tract?
mechanical and chemical breakdown of food, and the absorption of digested nutrients
Which part of the nervous system is in charge of digestion (except for swallowing and defecation)?
autonomic nervous system
What are the four layers of the GI tract wall?
mucosa, submucosa, muscularis, serosa
What is unique about the muscles of the esophagus?
top third is made of striated voluntary muscle, bottom third is made of smooth muscle
What is another name for the lower esophageal sphincter?
cardiac sphincter
What is another name for the myenteric plexus?
Auerbach’s plexus
What is the local mixing within regions of the GI tract?
segmentation
What is the phase in swallowing where the food becomes a bolus?
oropharyngeal phase
What are the three parts of the stomach?
fundus (top), body, pylorus (end)
What is the sphincter that separates the stomach from the duodenum?
pyloric sphincter
What are the three muscle directions in the stomach?
oblique, circular, and longitudinal
Which hormone is responsible for increasing peristalsis?
motilin
Which hormone stimulates the gastric process?
gastrin
Which hormone decreases peristalsis?
secretin
Which hormone inhibits the gastric process?
cholecystokinin
What three things determine gastrinal motility?
cephalic (thought, smell), gastric stomach signals, intestinal stimulation
What are the two things secreted in the fundus and body of the stomach?
HCl and pepsin
What stimulates the production of mucus in the stomach?
prostaglandins
Which artery supplies the jejunum and ileum?
mesenteric artery
What parts of the small intestine digests carbs, amino acids, and fats?
duodenum and jejunum
Which part of the stomach digests bile salts and B12?
ileum
What is the membrane that surrounds the organs of the abdomen?
peritoneum
What term means for “individual organs”?
visceral
What terms means for “the whole cavity”?
parietal
What is the vili’s purpose?
to increase the surface area for absorption
How does the absorption occur?
active transport, diffusion, or facilitated diffusion
What division of the nervous system is responsible for the function of the GI tract?
enteric nervous system
What are the pouches of the colon formed by contra/relax?
haustra
The large intestine has no vili like the small intestine. What does it have more of instead?
goblet cells and mucosal folds
Which artery supplies the large intestine?
mesenteric artery
What is the beginning of the colon called?
cecum
What is the part after the descending colon called?
sigmoid colon
What does the large intestine reabsorb?
water, acids and bases
What is the reflex that occurs when fecal mass gets passed on towards the rectum?
gastrocolic reflex
What is the reflex movement of feces into the rectum and out?
defecation reflex (invol and vol)
What are the three accessory organs of the GI tract?
liver, gallbladder, and pancreas
What are the cells of the liver called?
hepatocytes
What is the name of blood circulation that occurs around the liver?
hepatic portal circulation
How does bile leave the liver?
through the right and left hepatic duct
What are some functions of the liver?
nutrient metabolism, detoxification, store minerals and vitamins, stores blood, stimulates the clotting factor
What is the main purpose of the gallbladder?
stores and concentrates bile
What is the purpose of bile?
to neutralize chyme, create a favourable pH, emulsify lipids
What makes up bile?
bile salts, cholesterol, bilirubin, electrolytes, and water
What is the by-product of the destruction of RBC?
bilirubin (yellow tinge)
What are the two ducts that bring bile to the duodenum?
common bile duct and the cystic duct
What is the circulation of bile around the three organs called?
enterohepatic circulation
What is the digestive function of the pancreas?
secretion of enzymes and alkaline fluids
What is the name of the exocrine cells of the pancreas?
acinar cells
