Digestion and Absorption in the Small Intestine

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What is the primary function of the gastric phase of control?

To slow gastric emptying

To segment food in the small intestine

To prepare the arrival of the meal (correct)

To initiate secretion of digestive enzymes

Which phase of control occurs simultaneously with the others after the meal begins?

All phases occur sequentially

Gastric phase (correct)

Cephalic phase

Intestinal phase

Where do inhibitory reflexes originate to slow gastric emptying?

Pancreas

Large intestine

Small intestine (correct)

Stomach

What is released into the lumen of the GI tract during the intestinal phase of control?

Digestive enzymes and bicarbonate Signup and view all the answers

What is the primary function of the cephalic phase of control?

To prepare the stomach for food arrival Signup and view all the answers

During which phase of control is the meal in the small intestine?

Intestinal phase Signup and view all the answers

What is the primary site of fat digestion and absorption?

Small intestine Signup and view all the answers

What is released into the small intestine during the intestinal phase of control?

Pancreatic juice and bicarbonate Signup and view all the answers

Which structural modification of the small intestine forces chyme to spiral slowly, allowing more time for nutrient absorption?

Circular folds Signup and view all the answers

Which type of cells line the villi in the small intestine and are responsible for absorption?

Enterocytes Signup and view all the answers

What enzymes are found in the microvilli that complete the digestion of carbohydrates?

Brush border enzymes Signup and view all the answers

What is the primary form in which carbohydrates are absorbed in the small intestine?

Monosaccharides Signup and view all the answers

Which enzyme breaks down lactose into its monosaccharide components?

Lactase Signup and view all the answers

How are glucose and galactose primarily transported across the epithelial cells in the small intestine?

Secondary active transport Signup and view all the answers

Which enzyme continues the digestion of carbohydrates in the duodenum of the small intestine?

Pancreatic amylase Signup and view all the answers

By what mechanism are most nutrients absorbed in the small intestine?

Transepithelial transport Signup and view all the answers

What is the primary breakdown product of triglyceride molecules during digestion?

One monoglyceride and two free fatty acids Signup and view all the answers

Where does most digestion and absorption occur in the gastrointestinal tract?

Small intestine Signup and view all the answers

Which enzyme is essential for the bulk of fat digestion?

Pancreatic lipase Signup and view all the answers

What is the primary mechanism of water absorption in the small intestine?

Passive transport through osmosis Signup and view all the answers

Why is the stomach a poor absorptive area of the GI tract?

It lacks villi and has tight junctions between epithelial cells Signup and view all the answers

What type of substances can be absorbed in small quantities in the stomach?

Lipid-soluble substances Signup and view all the answers

What is the primary function of pancreatic lipase in fat digestion?

Breaking down fats into fatty acids and glycerol Signup and view all the answers

What is the primary mechanism of sodium transport in the small intestine?

Active transport through sodium-potassium pumps Signup and view all the answers