Digestive System
mucosa
lines digestive tract that secretes mucus
serosa
lines inner surfaces, pathway for blood vessels
Most of the digestive tract is lined by
simple columnar epithelium
gastric pits
small openings in the surface of the mucous membrane
defacation reflex
-peristaltic movements in large intestine poop out poop by receptors in rectal walls -rectal wall receptors stimulate neurons in spinal cord
pancreatic juice is an
alkaline fluid
mucous cells secrete
alkaline mucus; covers and protects epithelial cells
gastric phase
begins with arrival of food and stimulates stomach
pharyngeal phase
bolus comes in contact with sensory receptors
esophageal phase
bolus enters esophagus
Salivary amylase functions to digest
carbohydrates
Regions of the small intestine include all of the following except
cecum
Major regions of the large intestine include the
cecum, colon, and rectum
What are the 3 parts of the large intestine?
cecum, colon, rectum
Digestion refers to the
chemical breakdown of food
oral phase
compression of the bolus against the hard palate
submucosa
controls contraction of smooth muscle layers
intestinal phase
controls rate of gastric emptying when chyme enters small intestine
What are the 3 segments of the small intestine?
duodenum, jejunum, ileum
Plicae and intestinal villi
increase the surface area of the mucosa of the small intestine
esophagitis
inflammation of esophagus caused by weakened or relaxed lower esophageal sphincter as acids enter the lower esophagus
pancreatitis
inflammation of the pancreas; caused by blockage of the excretory ducts, bacterial/viral infections, ischema, drugs
6 processes of the digestive system
ingestion, mechanical, digestion, secretion, absorption, excretion
Functions of the stomach include
initiation of protein digestion, storage of recently ingested food, denaturation of proteins
parietal cells secrete
intrinsic factor and hydrochloric acid; facilitates the absorption of vitamin B12 and lowers the pH of gastric juice
segmentation
movements that churn and fragment digestive materials
chief cells secrete
pepsinogen; converts to pepsin
Waves of the muscular contractions that propel the contents of the digestive tract from one point to another are called
peristalsis
cephalic phase
prepares stomach to receive food from senses
Which of the following is a major action of the large intestine?
reabsorb water
What are the 3 functions of the large intestine?
reabsorbs water, makes poop, absorbs vitamins, stores poop
gastric juice
secretion of the gastric pits
secretin stimulates
secretion of the pancreatic juice
Regional movements that occur in the small movement and function to churn and fragment the digestive materials are called
segmentations
Each of the following organs is a component of the digestive tract EXCEPT one. Identify the exception.
spleen
The first place in which chemical digestion takes place is the
stomach
peristalsis
waves of muscular contractions that moves materials along the digestive tract