Digestive system

Question 1

functions of the digestive system

Answer 1

 Digestion
 Absorption
 Most controlled by nervous system and hormones

Question 2

Enzymes

Answer 2

protein catalysts that help chemical or metabolic reactions to occur without being permanently changed themselves
“- ase” ending indicates an enzyme (ex: sucrase)

Question 3

What are the salvary glands and what is their purpose?

Answer 3

 Chemical digestion:

 Salivary amylase – begins digestion of starch  Lingual lipase – begins digestion of lipids

Question 4

where is the espophagus and what are its functions?

Answer 4

 Swallow reflex
 Dysphagia – difficulty swallowing, serious health risk for inhaling food
 Lower esophageal sphincter (LES)  GERD = gastroesophageal reflux
disease  Peristalsis

Question 5

The stomach and digestive components.

Answer 5

 4 cup capacity
 Mechanical digestion
 Chemical digestion
 Acid
 Kill bacteria and parasites
 Inactivate biologically active proteins (“denatures” them)  Convert digestive enzymes into active forms
 Convert minerals into more soluble forms

Digestive System
 Stomach
 Chemical digestion, cont.
 Pepsin – protein-digesting enzyme
 Activated by stomach acid
 Digests proteins into di- and tripeptides
 Mucus
 Protects stomach from acid and enzymes

Question 6

What is the function of stomach acid?

Answer 6

Stomach acid protects us from the effects of biologically active proteins (enzymes and hormones) by denaturing them (change shape). When denatured, they are no longer active. Pepsin and other digestive enzymes break these proteins into amino acids, which are then absorbed and used by the body to make new proteins.

Question 7

Why is the presence of bovine growth hormone in milk, or any other protein-based hormone or enzyme from a plant or animal, not of great concern for human health?

Answer 7

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Question 8

While food proteins are denatured, what happens to pepsin?

Answer 8

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Question 9

Small intestine function

Answer 9

Most digestion and absorption

take place here

Question 10

Small intestine structural features

Answer 10

 Intestinal folds
 Villi
 Microvilli
 Absorptive cells
 Brush border enzymes

Question 11

what are the accessory organs to the small intestine and what is their function.

Answer 11

 Liver – produces bile from cholesterol
 Gall bladder – stores bile until dietary fat enters small intestine
 Pancreas – produces pancreatic juice
 Enzymes, bicarbonate

Question 12

Why is there a thick layer of mucus covering the stomach wall?

Answer 12

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Question 13

Why is there NOT a thick layer of mucus covering the small intestine villi and absorptive cells?

Answer 13

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Question 14

What is the purpose of bicarbonate made by the pancreas?

Answer 14

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Question 15

function of the large intestine

Answer 15

 Absorbs some water, vitamins and minerals

 Bacterial colonies ferment soluble fibers, produce vitamin K

Question 16

some diseases of the gi tract

Answer 16

Ulcers
 GERD
 Constipation
 Diarrhea
 IBS/IBD
 Crohn’s disease  Cancer