Digestive System

Question 1

Mucous Surface Cells:
1) Stimulus?
2) Substance Secreted?
3) Function of Secretion

Answer 1

1) Tonic secretion; irritation of the mucosa
2) Mucus
3) Physical Barrier between lumen and epithelium

Question 2

Mucous Neck Cells:
1) Stimulus?
2) Substance Secreted?
3) Function of Secretion

Answer 2

1) Secreted with mucus
2) Bicarb
3) Buffers gastric acid to prevent damage to the epithelium

Question 3

Parietal Cells (Gastric Acid/HCl)
1) Stimulus?
2) Substance Secreted?
3) Function of Secretion

Answer 3

1) Ach, gastrin, histamine
2) Gastric Acid (HCl)
3) Activates pepsin; kill bacteria

Question 4

Parietal Cells (Intrinsic Factor)
1) Stimulus?
2) Substance Secreted?
3) Function of Secretion

Answer 4

1) Ach, gastrin, histamine
2) Intrinsic Factor
3) Complexes with vitamin B12 to permit absorption

Question 5

Enterochromaffin-like Cells
1) Stimulus?
2) Substance Secreted?
3) Function of Secretion

Answer 5

1) Ach, gastrin
2) Histamine
3) Stimulate gastric acid secretion

Question 6

Chief Cells (Pepsin(ogen))
1) Stimulus?
2) Substance Secreted?
3) Function of Secretion

Answer 6

1) Ach, acid secretion
2) Pepsin
3) Digest proteins

Question 7

Cheif Cells (Gastric Lipase)
1) Stimulus?
2) Substance Secreted?
3) Function of Secretion

Answer 7

1) Ach, acid secretion
2) Gastric Lipase
3) Digest fats

Question 8

D-Cells
1) Stimulus?
2) Substance Secreted?
3) Function of Secretion

Answer 8

1) Acid in the stomach
2) Somatostatin
3) INHIBITS gastric acid secretion

Question 9

G-Cells
1) Stimulus?
2) Substance Secreted?
3) Function of Secretion

Answer 9

1) Ach, peptides, amino acids
2) Gastrin
3) STIMULATES gastric acid secretion

Question 10

I-Cells
1) Stimulus?
2) Substance Secreted?
3) Function of Secretion

Answer 10

1) Fatty acids, some amino acids
2) Cholecystokinin (CCK)
3) Stimulates gallbladder contraction + pancreatic enzyme secretion; inhibits gastric emptying and acid secretion

Question 11

S-Cells
1) Stimulus?
2) Substance Secreted?
3) Function of Secretion

Answer 11

1) Acid in the small intestine
2) Secretin
3) Stimulates bicarb secretions; inhibits gastric emptying + acid secretion

Question 12

K-Cells
1) Stimulus?
2) Substance Secreted?
3) Function of Secretion

Answer 12

1) Glucose, fatty acids, and amino acids in the small intestine
2) Gastric Inhibitory Peptide (GIP)
3) Stimulates insulin release; inhibits glucagon release and gastric function

Question 13

Oral Cavity and Esophagus:
Secretion
Digestion
Absorption
Motility

Answer 13

S: Saliva
D: Carbohydrates
A: None
M: Chewing & Swallowing

Question 14

Stomach:
Secretion
Digestion
Absorption
Motility

Answer 14

S: HCl, Pepsinogen (parietal), Gastric Lipase (chief), Mucus and bicarbonate (surface mucous), histamine (ECL)
D: Proteins, Fats (minimal)
A: Lipid-soluble substances (alcohol and aspirin)
M: Peristaltic mixing and propulsion

Question 15

Small Intestine:
Secretion
Digestion
Absorption
Motility

Answer 15

S: Enzymes (enterocytes), mucus (goblet); hormones: CCK, secretin, GIP, and others (endocrine); Enzyme and bicarbonate (exocrine pancreas); Bile (liver + stored in the gallbladder
D: Polypeptides, carbs, fats, nucleic acids
A: Amino acids and small peptides; monosaccharides, fatty acids, monoglycerides, cholesterol; nitrogenous bases; water; ions, minerals, vitamins
M: Mixing and propulsion primarily by segmentation; some peristalsis

Question 16

Large Intestine:
Secretion
Digestion
Absorption
Motility

Answer 16

S: Mucus (goblet cells)
D: None (except bacteria)
A: Ions, minerals, vitamins; water; small organic molecules made by gut bacteria
M: Segmental mixing; mass movement for propulsion

Question 17

Gastric Juice pH

Answer 17

~2

Question 18

Bicarb barrier pH

Answer 18

~7

Question 19

Common Hepatic Duct

Answer 19

takes bile made in the liver to the gallbladder for storage

Question 20

Common Bile Duct

Answer 20

takes bile from the gallbladder to the lumen of the small intestine

Question 21

Hepatic Artery

Answer 21

brings OXYGENATED blood containing metabolites from peripheral tissues to the liver

Question 22

Hepatic Portal Vein

Answer 22

blood rich in absorbed nutrients from the gastrointestinal tract and contains hemoglobin breakdown products from the spleen leaves liver through here

Question 23

Sphincter of Oddi

Answer 23

controls release of bile and pancreatic secretions into the duodenum

Question 24

What is absorbed from the gastrointestinal tract and goes TO the liver via the hepatic portal vein?

Answer 24

bilirubin
nutrients
drugs
foreign substances

Question 25

What metabolites and drugs from peripheral tissues goes TO the liver via the hepatic artery?

Answer 25

bilirubin
metabolites of hormones and drugs
nutrients

Question 26

What is secreted into the duodenum FROM the liver through the bile duct?

Answer 26

bile salts
bilirubin
water, ions
phospholipids

Question 27

What metabolites are sent to the peripheral tissues FROM the liver through the hepatic vein?

Answer 27

glucose
plasma proteins: albumin, clotting factors, angiotensinogen
Urea
Vitamin D, somatomedins
Metabolites

Question 28

What processes happen in the liver?

Answer 28

glucose and fat metabolism
protein synthesis
hormone synthesis
urea production
detoxification
storage

Question 29

Secretion

Answer 29

movement of material from cells into lumen or ECF

Question 30

Digestion

Answer 30

chemical and mechanical breakdown of food into absorbed units

Question 31

Absorption

Answer 31

movement of material from GI lumen to ECF

Question 32

Motility

Answer 32

movement of material through the GI tract as a result of muscle contraction