Digestive System Flashcards
extracellular digestion
obtaining nutrients from food within the lumen of the alimentary canal
enteric NS
- 100 million neurons that are present in the walls of the GI system
- trigger peristalsis
- heavily regulated by the autonomic NS
- high parasympathetic activity to encourage peristalsis and exocrine secretion, hence lethargy after meals
basic path of food
oral cavity
pharynx
esophagus
stomach
small intestine
large intestine
rectum
enzymes and lubricaron provided by salivary glands, pancreas, liver, gallbladder
how many salivary glands in mouth?
3
which branch of NS triggers salivation?
parasympathetic
enzymes of the mouth
salivary amylase and lipase
- hydrolyzing starch into smaller sugars (maltose and dextrins)
- catalyzes hydrolysis of lipids
3 parts of pharynx
nasopharynx, oropharynx, laryngopharynx
food prevented from entering the larynx during swallowing by the epiglottis
comp of sections of the esophagus
top~> skeletal, somatic
mid~> mix
bottom~> smooth, autonomic
which two sphincters must the bolus pass through in the esophagus?
upper and lower esophageal sphincters
passage of bolus through stomach
esophagus
fundus
body
antrum
pylorus
pyloric sphincter
duodenum
gastric glands respond to signals from…
vagus nerve
gastric glands cell types
- mucous: bicarb rich mucus to protect walls from stomach acid
- chief cells: pepsinogen, proteolytic enzyme
- parietal cells: HCl, intrinsic factor which is glycoprotein involved in proper absorption of B12
pyloric glands of stomach
G-cells: gastrin, which signal to parietal cells to produce more HCl and induces more stomach contractions
food leaves stomach through…
pyloric sphincter and enters the duodenum
entrance of chyme into duodenum causes the release of…
brush-border enzymes
disaccharidases (maltase, isomaltase, lactase, and sucrase) and peptidases (including dipeptidase)