Chapter 17

What are the functions of the digestive system?

• mechancial and chemical

• ingestion

• propulsion

• absorption

• defection

What are the layers of the alimentary canal?

muscosa, submuscosa, muscularis (externa), and serosa

What is peristalsis?

ring of contraction progresses down, propels food particles down the tract in a wavelike motion

where does peristalsis occur?

alimentary canal

What part of the ANS stimulates the digestive tract?

parasympathetic nervous system

What’s salivary amylase?

enzyme that hydrolyzes (digests) starch in mouth

what is salivary amylase’s function

splits starch and glycogen molecules into disaccharides, starts chemical digestion of carbohydrates

what structure closes off the glottal opening

epiglottis

What are the regions of the stomach?

cardia, fundus, body and pylorus

what is gastrin?

hormone secreted by the stomach that stimulates gastric juice secretion

what’s gastrin’s function?

acts to increase the secretory activity of gastric glands

what’s cholecystokinin

released by small intestine cells when proteins and fat enters the small intestine

what’s the function of cholecystokinin

decreases gastric motility

what’s secretin

hormone from the small intestine that stimulates the pancreas to release pancreatic juice rich in bicarbonate ion

what’s secretin’s function?

travels to the target (pancreas) and stimulates the secretion of abundant pancreatic fluid by duct cells

what regulates the secretion of pancreatic enzymes?

secretin and CCK

what’s the digestive functioning portion of bile

breaks down fats through process called emulsification

What are the functions of the liver

detoxification, carbohydrate metabolism, lipid metabolism, protein metabolism, storage,blood filtering, and secretion

what are chylomicrons

new triglyceride clusters incased in protein and absorbed by lacteals

what is the function of chylomicrons

transport dietary fats to muscle and adipose cells

What are the organs of the GI tract

mouth, pharynx, esophagus, stomach, small intestine and anal canal

what is intrinsic factor

parietal cells of the gastric glands

why is intrinsic factor important

necessary for vitamin B12 absorption in the small intestine

where is the vomit center

medulla oblongata

what is ghrelin

a hormone that the stomach secretes

what does ghrelin stimulate?

enchances appetite by stimulating the release of neuropeptide Y