Digestive system (9)

Question 1

Stomach: secretes six products

Answer 1

1. HCl ( kills microbes, denatures protein, and convert pepsinogen to pepsin)
2. Pepsinogen (cleaved in the stomach to pepsin; an enzyme that partially digests protein)
3. Mucus (protect mucosa)
4. Bicarbonate (protects mucosa)
5. Water (dissolves and dilutes ingested material)
6. Intrinsic factor (required for normal absorption of vitamin B 12)

Question 2

Gastric Gland: contain three cell types

• Mucous
• Cheif cells
• Parietal cells

Answer 2

Mucous cells: produce bicarbonate rich mucus to protect stomach cells.
Chief cells: secrete pepsinogen
Parietal: secretes HCl –> cleaves pepsinogen to pepsin
Parietal is like Parental protects it
also secretes intrinsic factor, a glycoprotein involved in the proper absorption of vitamin B12.

Question 3

Pepsin

Answer 3

digests protein by cleaving peptide bonds, resulting in short peptide segments.

Question 4

Pyloric Gland: contains G cells

Answer 4

G-cells: secrete gastrin, a peptide hormone that increases HCl secretion and gastric motility.

Question 5

Duodenum

Answer 5

involved in chemical digestion

Question 6

Brush border Enzyme

Answer 6

Diasccharideses digests disaccharides

Brush border peptidases include aminopeptidase and dipeptidases.

Question 7

Diasccharideses

Answer 7

maltase digests maltose
sucrase ———> sucrose
lactase————> lactose

Question 8

Aminopeptidases (enzyme) (from brush border)

Answer 8

removes N-terminal amino acid from a peptide

Question 9

Dipeptidases (enzyme) (from brush border)

Answer 9

cleaves peptide bonds of dipeptides to release free amino acids.

Question 10

Enteropeptidase

Answer 10

the enzyme that is critical for activation of trypsinogen. Trypsinogen will then activate trypsin.
Trypsin will activate procarboxypeptidases A and B.

Deficiency of enteropeptidase will lead to trypsinogen deficiency and protein will not cleave and which results in amino acids deficiency.

Question 11

Secretin (hormone)

Answer 11

secretin stimulates the release of pancreatic juice into the digestive tract and slows motality.

Question 12

Cholecystokinin (CCK) (hormone)

Answer 12

stimulates bile release from the gallbladder, the release of pancreatic juice, and satiety from the brain.

Question 13

Bile

Answer 13

emulsify fats and cholesterol into micelles.

produced in the liver and stored in the gallbladder.

Question 14

Pancreatic juice

Answer 14

a complex mixture of several enzymes in a bicarbonate-rich alkaline solution.

Pancreatic juice contains an enzyme that can digest all three types of nutrients: carbohydrates, fat, proteins.

acinar cells: produces pancreatic juice

Question 15

Pancreatic lipase

Answer 15

capable of breaking down fats into free fatty acids and glycerol.

Question 16

Liver

Answer 16

takes up excess sugar to create glycogen, a storage form of glucose.
stores fats as triacylglycerols.

Question 17

Bilirubin

Answer 17

The biproduct of the breakdown of hemoglobin. Bilirubin travels to the liver, where it is conjugated and secreted into the bile for excretion.

Unable to process or excrete bilirubin, will cause jaundice.

Question 18

Amylase

Answer 18

alpha-amylase secreted in the mouth, initiates the digestion of carbohydrates by cleaving alpha-1,4 bonds but not alpha- 1,6 bonds.

secreted by the pancreas also, breaks down large polysaccharides into small disaccharides.

Question 19

Absorption

Answer 19

Jejunum and ileum involve in absorption.

• Water-soluble such as monosaccharides, amino acids, water-soluble vitamins, and water enters the capillary bed.
• Fat-soluble, such as fats, cholesterol, and fat-soluble vitamins (A, D, E, K)

Question 20

Chylomicrons

Answer 20

-Triglycerides and cholesterol molecules are packaged into chylomicrons.

enter the lymphatic system through lacteals. Lacetals converge and enter the venous circulation at the thoracic duct, which empties into the left subclavian duct.

Question 21

Large Intestine

Answer 21

Absorbs water and salt, forming semisolid feces.

Question 22

Liver failure

Answer 22

The high concentration of ammonia in the blood

Low concentration of clotting factors in the blood