Diegestive System II

Question 1

Function of the mucus surface cells

Answer 1

• Physical barrier between the lumen and the epithelium

Question 2

What stimulates the mucus surface layer?

Answer 2

• Tonic secret tonic secretion when the mucosa is irritated

Question 3

Mucous neck layer secretion and function

Answer 3

• Secrete bicarbonate which acts as a buffer to the gastric acid to prevent damage to the epithelium

Question 4

What stimulates the release of bicarbonate from mucous cells?

Answer 4

• Both the mucous and bicarbonate at decreased together

Question 5

The function of parietal cells secreting gastric acid?

Answer 5

• Activation of pepsin which kills bacteria

Question 6

Function of parietal cells secreting intrinsic factors

Answer 6

• Complexes with vitamin B12 to permit absorption

Question 7

What stimulates the release of gastric acid and intrinsic factors?

Answer 7

• Gastrin, acetylcholine and histamines

Question 8

What does the mucous neck and surface layer do for protection

Answer 8

• They protect the epithelial surface
• The NSAIDS and alcohol destroy the mucosal barrier which leads to gastric irritation

Question 9

Function of the secretaries of histamines from Enterochroffmaffin like cells

Answer 9

• Stimulates gastric acid secretion

Question 10

What stimulates the release of histamine?

Answer 10

Acetylcholine and gastrin

Question 11

Function of chief cells secreting pepsin

Answer 11

• For the digestion of proteins

Question 12

Function of chief cells secreting gastric lipase

Answer 12

• Initiates the digestion of fats

Question 13

What stimulates the release of pepsin and gastric lipase

Answer 13

• Acetylcholine for acid secretion

Question 14

Process of protein breakdown in the stomach

Answer 14

• Proteins initially breakdown in the stomach into pepsinogens
  -This causes the inactive enzyme to be secreted from chief cells
• The gastric acid then activates the inactive pepsin which digests the collagen in the meat

Question 15

Fat breakdown in the stomach

Answer 15

• Triglycerides are broken down by gastric lipase which is secreted by the chief cells
• This forms diglycerides and a free fatty acid

Question 16

Function of somatostatin secretion from D cells

Answer 16

• Inhibits the gastric acid secreation

Question 17

Function of gastrin secretion from G cells

Answer 17

• Stimulates gastric acid secretion

Question 18

What stimulates the D cells to secrete somatostatin

Answer 18

• Acid in the stomach

Question 19

What stimulates the G cells to secrete gastrin

Answer 19

• Acetylcholine, peptides and amino acids

Question 20

Paracrine effect

Answer 20

• ## Histamine stimulates G cells to secrete gastrin to stimulate the gastric acid secretion

Question 21

Somatostatin inhibition of paracrine effect

Answer 21

• Hormone that is a global inhibitor
• Inhibits secreation of histamines, gastrin and gastric acid secreation

Question 22

Histamine receptor antagonist

Answer 22

• Prevent histamine activation of gastrin-gastric acid secreation
• Drugs used to treat dyspepsia

Question 23

How does the bacteria Helicobacter pylori effect the stomach?

Answer 23

• Requires treatment with antibiotic
• Creates the inflammation of gastric mucosa

Question 24

Intrinsic factor

Answer 24

• Responsible for binding to vitamin B12
• Without binding B12 cannot be absorbed
• Required for erythropoeisis and DNA formation

Question 25

Intestinal secreations

Answer 25

- Mucus is secreted by the duodenal glands and goblet cells - Protection of of duodeum from gastric acids and digestive juices - Sucrase, lactase, maltase and amylase digest carbs via glucose transporters

Question 26

Cholecytokinn

Answer 26

- Stimulates the gall bladder contractions, pancreatic enzyme secreation and inhibition of gastric emptying and secretion

Question 27

Secretin

Answer 27

- Stimulates the bicarbonate secretion - Inhibition of gastric emptying and secretion

Question 28

Gastric inhibitory peptide

Answer 28

- Inhibition of gastric emptying and secreations

Question 29

Glucagon like peptide

Answer 29

- Inhibition of gastric emptying and secreation - Decrease in appetiete

Question 30

Liver

Answer 30

- Recieves 30% cardiac output - Contains heptocytes for metabolism - Glucose, fat metabolism and protien synthesis - Hormone synthesis, detoxification, urea production and storage

Question 31

Gallbladder

Answer 31

- Small pouch like organ under liver - Storage of bile and bile is passed from gall to liver via bile ducts

Question 32

Bile

Answer 32

- Non-enzymatic solution secreated from heptocytes - Contains bile acids, biliburin and cholesterol - Bile salts act as detergents to solublise fat and move them forward in small intestine

Question 33

Process of fat absorption

Answer 33

- Bile salts coat fat droplet forming an emulsion - Pancreatic lipase break them into monoglycerides - Monoglycerides broken into free fatty acids and cholesterol which diffuse through entrocytes - Absorbed fat cholesterol and protiens form chylomicron - Chylomicrons are removed through lymphatic system

Question 34

# Metabolisation in Pancreas Exocrine glands

Answer 34

- Mostly exocrine tissue - Pancreatic enzymes to aid digestion - Alkaline clear milky liquid containing amylase lipase and trypsin

Question 35

# Metabolisation in Pancreas Endocrine glands

Answer 35

- Small percentage in pancreas lots of endocrines - Ilets of langahan insulin glucose regulation occours

Question 36

# Pancreas secretions Ancinar cells

Answer 36

- Exocrine cells that release digestive juices send via duct which creates bicarbonate mucus which neutralises the acidic chyme also activates enzymes