Chapter 3

Question 1

What is digestion?

Answer 1

a process where food is broken down into absorbable units

Question 2

what is the lumen?

Answer 2

the space within a vessel such as the intestine.

Question 3

GI tract?

Answer 3

the gastrointestinal tract, flexible muscular tube that expands from the mouth, through the esophagus, stomach, small intestine, large intestine, and rectum to the anus.

Question 4

bolus?

Answer 4

a mouthful of food that has been chewed and swallowed.

Question 5

chyme?

Answer 5

semiliquid mass of a partly digested food expelled by the stomach into the duodenum.

Question 6

Where does digestion begin?

Answer 6

in the mouth

Question 7

order of digestion?

Answer 7

mouth, pharynx, salivary glands, epiglottis, trachea, esophagus, esophagus sphincters, diaphragm, stomach, pyloric sphincter, liver, gallbladder, bile duct, appendix, small intestine, ileocecal valve, pancreas, pancreatic duct, large intestine, rectum, anus.

Question 8

how many organs are involved?

Answer 8

21

Question 9

what is a sphincter? how many prevent backflow?

Answer 9

the passage that sends the food from one place to another and helps prevent backflow. three.

Question 10

how many layers of muscle are in the stomach?

Answer 10

three, longitudinal, circular, and diagonal

Question 11

three segments of the small intestine?

Answer 11

the duodenum connected to the stomach, the jejunum then the ileum connected to the colon.

Question 12

what is the appendix?

Answer 12

a narrow, finger-shaped pouch that projects out from the colon.

Question 13

what does the large intestine absorb?

Answer 13

absorbs water and salt from items that have not been digested, gets rid of the waste leftover.

Question 14

parts of the large intestine? (colon)

Answer 14

the cecum, ascending colon, transverse colon, descending colon, and sigmoid colon.

Question 15

what is an enzyme?

Answer 15

protein that facilitates a chemical reaction, making a molecule, breaking a molecule, changing the arrangement of it exchanging.

Question 16

role of saliva in digestion? gastric juice?

Answer 16

helps lubricate the food so it can go down the esophagus. gastric juice activates digestive enzymes which break down proteins.

Question 17

purpose of sodium bicarbonate?

Answer 17

protects the duodenum by neutralizing the acid that comes from the stomach.

Question 18

purpose of bile, where it is produced, and where it is stored?

Answer 18

bile prepares fats and oils for digestion, made by the liver, stored in the gallbladder, and released into the small intestine when needed.

Question 19

where do most of the absorption of nutrients occur?

Answer 19

small intestine

Question 20

absorption techniques?

Answer 20

simple diffusion, some nutrients are absorbed like water and lipids, cross into intestinal cells freely.
facilitated transport, some are absorbed like water-soluble nutrients, need a specific carrier to transport them from one side of the cell membrane to the other side.
active transport, some nutrients are absorbed like glucose and amino acids, move against a concentration gradient, require energy.

Question 21

anatomy of the absorptive system? purpose?

Answer 21

small intestine, villi, fingerlike projections from the folds of the small intestine. microvilli, tiny, hairlike projections on each cell of every villus that can trap nutrient particles and transport them into cells. Crypts, tubular glands that secrete the intestinal juices into the small intestine. globet cells secrete mucus.

Question 22

the first organ to receive absorbed nutrients from the GI tract?

Answer 22

the liver

Question 23

probiotics?

Answer 23

live microbes that change conditions in the GI tract in ways that benefit health, alleviate diarrhea, constipation, inflammatory bowel syndrome, ulcers, allergies, etc.

Question 24

prebiotics?

Answer 24

fibers and some other components that encourage growth and activity of bacteria, reduce GI infections, inflammation, and disorders.

Question 25

what do microbes in the GI tract produce?

Answer 25

enzymes

Question 26

common digestive problems?

Answer 26

choking, vomiting, diarrhea, irritable bowel syndrome, colitis, celica disease (gluten), belching, intestinal gas, and ulcers.