A&P: DIGESTION

Question 1

Digestion

Answer 1

Breaking down nutrients into small, soluble molecules that can be absorbed into the blood

Question 2

[digestion]
Mechanical digestion

Answer 2

Breaking food into smaller pieces

Question 3

[digestion]
Chemical digestion

Answer 3

-Breaking nutrients into small molecules
-occurs by hydrolysis (splitting molecules by adding water)
-sped up by digestive enzymes (hydrolases)

Question 4

Hydrolysis

Answer 4

Splitting molecules by adding water

Question 5

Hydrolases

Answer 5

Digestive enzymes

Question 6

[Digestive system]
Alimentary canal

Answer 6

-Tube that extends between mouth and anus
-organized into specialized regions that carry out specific phases of the digestive process
(E.g. mechanical digestion, chemical digestion, absorption)

Question 7

[digestive system]
Accessory organs

Answer 7

-liver, gallbladder, and pancreas

Question 8

[digestive system]
Digestive process
1/3

Answer 8

-food enters through mouth, chewed (mechanical digestion), increasing SA, making easier to swallow and digest
-presence of food stimulates salivary glands to release saliva, which cont. enzyme amylase
-amylase breaks down starch into smaller carbohydrate molecules (monosaccharides and disaccharides)
-as the food is swallowed, it is pushed down by tongue into pharynx (throat), which leads to windpipe and esophagus
-during swallowing, the top of the windpipe is covered by the epiglottis to prevent food from entering the respiratory system
-from the esophagus the food is passed to the stomach by muscular contractions called peristalsis

Question 9

[digestive system]
Digestive process
2/3

Answer 9

-the lining of the stomach releases gastric juice, which is made of hydrochloric acid and proteases (protein digesting enzymes)
-the environment of the stomach is acidic, having pH of approximately 3, bc gastric enzymes work best in this environment
-cells in the stomach lining secrete mucus, which protects the stomach wall from the action of the very acidic gastric juice
-smooth muscles of the stomach mix the partially digested food, and the result is a liquid called chyme
-chyme is released into the pyloric sphincter
-most of the digestion of food takes place in the small intestine which can be up to 6 meters long in humans

Question 10

[digestive system]
Digestive process
3/3

Answer 10

-small intestine is the major site for digestion and absorption of nutrients into the bloodstream
-digestive enzymes are secreted by intestinal glands
-liver, pancreas, and gallbladder also contribute to digestion
-the liver produces bile, a substance stored in the gallbladder, which helps the breakdown of fats
-the pancreas supplies a number of enzymes needed for digestion
-to facilitate absorption, the small intestine is lined with villi, which greatly increase the intestinal SA for the absorption of end products of digestion into the blood and lymph
-undigested food is moved to the large intestine or colon, which is responsible for absorbing water that has entered the alimentary canal
-the waste or feces that moves along the colon by peristalsis becomes increasingly solidified and is ultimately stored in the rectum for egestion (elimination from the body)
-diarrhea is a result of peristalsis moving feces through the colon too quickly so that water is not reabsorbed, whereas constipation results from too little peristalsis and thus too much reabsorption of water

Question 11

[digestive system]

Answer 11

Question 12

[chemical digestion]
State Nutrient, Enzymes, End product, and Location for the following nutrients:
Carbohydrate
Protein
Lipids

Answer 12