Phases of Carbohydrate Digestion

Question 1

What drugs can reduce nausea and vomiting?

Answer 1

Antiemetics
- H1 receptor blockers
- Gravol is an example of this

Question 2

3 phases of digestion

Answer 2

• Cephalic phase
• Gastric phase
• Intestinal phase

Question 3

What is the stimulus for the cephalic phase?

Answer 3

Stimulus - sight, smell, taste or thoughts of food

Neural control - medulla oblongata

Question 4

What changes occur during the cephalic phase?

Answer 4

• increases secretions from salivary glands, stomach, intestines
• increases motility of the stomach and the small intestine

Question 5

What is the stimulus for the gastric phase?

Answer 5

Stimulus - bolus in the stomach causing stretching and the presence of amino acids

Neural control - sensory information to the submucosal plexus and the myenteric plexus

Hormonal control - gastrin

Question 6

What are the changes that occur in the gastric phase?

Answer 6

• increased secretions from stomach and intestine
• increased motility in stomach and increased gastric emptying

Question 7

Which neurons control secretions and motility in the digestive system?

Answer 7

• myenteric plexus - motility
• submucosal plexus - secretions

Question 8

What is the stimulus for the intestinal phase?

Answer 8

• presence of chyme in the intestine
• sensory information to submucosal plexus and the myenteric plexus
• hormonal control from S cells (secretin), CCK cells (CCK), and K cells (GIP)

Question 9

What changes occur during the intestinal phase?

Answer 9

• increased secretions from the intestine and the pancreas (bicarbonate from ductal cells, digestive enzymes from acinar cells, and insulin from beta cells (GIP causes insulin release))
• increased motility in intestine and gallbladder for bile release
• inhibits secretions from the stomach and decreases motility of the stomach and decreased gastric emptying

Question 10

What factors will increase gastric emptying (pyloric sphincter opening)?

Answer 10

• distension of stomach
• partially digested proteins

Question 11

What factors will decrease gastric emptying (pyloric sphincter closing)?

Answer 11

-distension of duodenum
- partially digested proteins and fats
- solid meal
- meal w lipids
- calorically dense meal

Question 12

What is the reaction that salivary and pancreatic amylase catalyze?

Answer 12

• starch into maltose

Question 13

How does our body metabolize complex carbohydrates?

Answer 13

• brush border enzymes catalyze reactions to make them into simpler sugars which can enter our bloodstream and can be used