Unit 4 Lecture 27

Question 1

What is the importance of the small intestine?

Answer 1

site of most digestion and absorption

Question 2

What are the 3 sections of the small intestine?

Answer 2

duodenum, jejunum and ileum

Question 3

What is the sphincter in the small intestine?

Answer 3

ileocecal sphincter

Question 4

What is found on the mucosa layer of the small intestine that increases surface area for digestion and absorption??

Answer 4

1. circular folds
2. villi
3. microvilli

Question 5

What are the cells found in the small intestine and what do they secrete?

Answer 5

1. absorptive cells - absorb nutrients
2. goblet cells - secrete mucous
3. enteroendocrine cells (S, CCK and K) - S secretes secretin, CCK secretes cholesystokinin, K secretes GIP
4. Paneth cells - secretes lysozomes and can do phagocytosis

Question 6

What is found on the surface of microvilli?

Answer 6

brush border enzymes

Question 7

What do brush border enzymes do?

Answer 7

chemically breakdown of carbohydrates, proteins and nucleosides

Question 8

What is found in the lumen of the small intestine?

Answer 8

pancreatic juices and chyme

Question 9

What is chyme made of?

Answer 9

amylase, proteases, lipase and nucleases

Question 10

Label the complete flow of bile

Answer 10

• hepatocytes in liver
• starts with a C
• bile duct
• right and left hepatic duct
• common hepatic duct
• common bile duct and pancreatic duct
• hepatopancreatic ampulla
• duodenum

Question 11

Where does the liver, gallbladder and pancreas empty into?

Answer 11

duodenum of small intestine

Question 12

What are the main categories of enzyme secreted by the pancreas?

Answer 12

1. Amylase
2. Proteases
3. Lipase
4. Nucleases

Question 13

What amylase enzyme is secreted by the pancreas?

Answer 13

pancreatic amylase

Question 14

What protease enzymes are secreted by the pancreas?

Answer 14

1. Trypsin
2. chymotrypsin
3. carboxypeptidase
4. elastase

Question 15

What lipase enzyme is secreted by the pancreas?

Answer 15

pancreatic lipase

Question 16

What nucleases enzymes are secreted by the pancreas?

Answer 16

ribonuclease and deocyribonuclease

Question 17

What are proteases?

Answer 17

Secreted as inactive precursors (like pepsinogen in the stomach)

Question 18

What activates trypsinogen to trypsin?

Answer 18

Enteropeptidase (on brush border cells)

Question 19

What does trypsin activate?

Answer 19

Activates chymotrypsinogen, procarboxypeptidase and proelasease

Question 20

Where are carbohydrates digested?

Answer 20

• Mouth
• Stomach
• Pancreas
• Small intestine

Question 21

What digests carbohydrates in the mouth?

Answer 21

Salivary amylase

Question 22

How are carbohydrates digested in the stomach?

Answer 22

Mechanical digestion (no chemical digestion)

Question 23

What digests carbohydrates in the small intestine?

Answer 23

Brush border enzymes Maltase, Sucrase, and lactase

Question 24

What do the brush border enzymes in the small intestine act on?

Answer 24

disaccharides (maltose, sucrose, and lactose)

Question 25

What do the brush border enzymes in the small intestine produce?

Answer 25

monosaccharides (fructose, glucose and galactose)

Question 26

What does sucrase produce?

Answer 26

glucose and fructose

Question 27

What does lactase produce?

Answer 27

glucose and galactose

Question 28

What does maltase produce?

Answer 28

glucose and glucose

Question 29

Where are the monosaccharides absorbed into?

Answer 29

epithelial cells

Question 30

How do glucose and galactose enter epithelial cells?

Answer 30

secondary active transport

Question 31

How does fuctose enter epithelial cells?

Answer 31

facilitated diffusion

Question 32

Where do the monosaccharides go when the leave epithelial cells?

Answer 32

bloodstream

Question 33

How do all monosaccharides leave epithalial cells?

Answer 33

facilitated diffusion

Question 34

Where are proteins digested in the body?

Answer 34

- Mouth - Stomach - Pancreas - Small intestine

Question 35

How are proteins digested in the mouth?

Answer 35

mechanical digestion ONLY

Question 36

What chemicals digest proteins in the stomach?

Answer 36

HCl and pepsin

Question 37

What enzymes digest proteins in the pancreas?

Answer 37

Pancreatic enzymes (proteases) in pancreatic juices

Question 38

What enzymes digest proteins in the small intestine?

Answer 38

Brush border enzymes (aminopeptidase and dipeptidase)

Question 39

Where are amino acids and dipeptides absorbed?

Answer 39

epithelial cells od duodenum and jejunum

Question 40

How are amino acids and dipeptides absorbed into epithelial cells?

Answer 40

facilitated diffusion

Question 41

Where are lipids digested?

Answer 41

- BEGINS in mouth - stomach - pancreas - liver

Question 42

What enzymes digest lipids in the mouth

Answer 42

lingual lipase in saliva

Question 43

What enzymes digest lipids in the stomach?

Answer 43

gastric lipase

Question 44

What enzymes digest lipids in the pancreas?

Answer 44

pancreatic lipase in pancreatic juice

Question 45

What do pancreatic juices do in the stomach?

Answer 45

split triglycerides into fatty acids and monoglycerides

Question 46

What digests lipids in the liver?

Answer 46

bile

Question 47

Are lipids digested in the small intestine?

Answer 47

no

Question 48

What are the two types of lipids?

Answer 48

short chain and long chain lipids

Question 49

How are short chain lipids (fatty acids) absorbed?

Answer 49

simple diffusion

Question 50

How are long chain lipids (fatty acids) and monoglycerides absorbed?

Answer 50

simple diffusion through cells - bile salts are reabsorbed and later recycled (into bile) by liver - fat-soluble vitamins (A,K,D3, E) enter cells with lipids