Phys 65: GI secretion

Question 1

Cells on surface of GI epithelium

Answer 1

Goblet cells AKA mucous cells

Question 2

Invaginations of epithelium into submucosa aka

Answer 2

Pits

called crypts of lieberkün in intestine

Question 3

Glandular cell secretions accomplished via

Answer 3

Exocytosis

Question 4

Daily secretion of saliva amount

Answer 4

800-1500 ml

Average 1000ml

Question 5

Two major saliva protein secretion types

Answer 5

Serous secretion

Mucous secretion

Question 6

Salvia serous secretion protein

Answer 6

ptyalin

type of α-amylase

disgests starches

Question 7

Mucous saliva secretion protein

Answer 7

Mucin

Acts as lubricant

Question 8

Ions of saliva

Answer 8

Large quantities of HCO3- and K+

Question 9

Na+/K+ balance in saliva

Answer 9

Na+ is reabsorbed in exchanger for K+

Question 10

Cl- during saliva production

Answer 10

Reabsorbed passively

Question 11

Factors in saliva that destroy bacteria

Answer 11

Thiocynate ions

Proteolytic enzymes —> most important is lysozyme

Antibodies

Question 12

Superior salivatory nucleus CN

Answer 12

VII

Question 13

Inferior salivatory nucleus CN

Answer 13

CN IX

Question 14

Esophageal secretion type

Answer 14

Mainly mucous for swallowing lube

Question 15

Oxyntic glands secrete

Answer 15

Hydrochloric acid, pepsinogen, intrinsic factor, mucus

Question 16

Pyloric glands secrete

Answer 16

mainly mucus

also some gastrin

Question 17

Eenterochromaffin like cells secrete

Answer 17

Histamine

Question 18

Main driving force for hydrochloric acid secretion

Answer 18

H+/K+ ATPase

Question 19

Basic factors that stimulate gastric secretion

Answer 19

Acetylcholine

Gastrin

Histamine

Question 20

Intrinsic factor secreted by

Answer 20

Parietal cells

Question 21

Parietal cell destruction consequences

Answer 21

Achlorohydra (lack of acid)

Pernicious anemia due to B12 deficiency

Question 22

Type of mucus in stomach

Answer 22

Viscid mucus

Question 23

What does viscid mucus do

Answer 23

It is alkaline and forms protective layer around stomach

Question 24

ECL cells are stimulated by

Answer 24

Gastrin

Question 25

gastrin is secreted by

Answer 25

G cells in pyloric glands

Question 26

Three phases of gastric secretion

Answer 26

Cephalic Gastric Intestinal

Question 27

Cephalic phase of secretion

Answer 27

Occurs from neurogenic signals due to smell, taste and sight of food. Originate in amygdala and hypothalmus

Question 28

Gastric phase of secretion

Answer 28

Due to vagal stimulation from food entering stomach, local enteric reflexes and gastrin mechanism

Question 29

Gastrin is secreted due to

Answer 29

Protein rich food entering stomach.

Question 30

Intestinal phase of secretion

Answer 30

Presence of food in duodenum causes small amounts of gastric secretion

Question 31

Grastric secretion inhibition by

Answer 31

Reverse gastroenteric reflex Hormones: secretin, GLP-1, somatostatin

Question 32

Emotional stimuli does what to gastric secretion

Answer 32

increases acid secretion

Question 33

Pancreatic enzymes for protein digestion

Answer 33

Trypsin Chemotrypsin Caboxypolypeptidase

Question 34

Pancreatic enzymes for fat digestion

Answer 34

Pancreatic lipase Phospholipase Cholesteroesterase

Question 35

Pancreatic proteolytic enzymes are secreted as_____. Later in the GI tract they are ____

Answer 35

inactive forms Later activated

Question 36

Activation of proteolytic enzyme mechanism

Answer 36

Trypsinogen is activated to trypsin by enterokinase Trypsin activates everything else

Question 37

How is pancreas protected from proteolytic enzymes

Answer 37

Also secretes trypsin inhibitor When trypsin inhibitor is overwhelmed, pancreas digests itself with its own proteolytic enzymes

Question 38

Bicarb is secreted into lumen via

Answer 38

Cl-/HCO3- exchanger

Question 39

Secretion of bicarb stimulated by (GI)

Answer 39

Secretin

Question 40

How is acidic stomach chyme neutralized in instestine

Answer 40

Via bicarb secretion

Question 41

Cholecystokinin (CCK) function

Answer 41

stimulates pancreatic secretion

Question 42

Liver bile secretion stimulated by

Answer 42

Secretin

Question 43

Gall bladder emptying stimulated by

Answer 43

Cholecystokinin (also weakly vagal)

Question 44

Sphincter of odi

Answer 44

Keeps bile in gall bladder till its needed

Question 45

Precursos of bile salts

Answer 45

Cholesterol

Question 46

Percent of bile salts that are recirculated

Answer 46

94%

Question 47

Gallstones formed by

Answer 47

Precipitation of cholesterol

Question 48

Mucous secreting glands in duodenum

Answer 48

Brunners glands

Question 49

Brunners glands activated by

Answer 49

Tactile stimulation Vagal stimulation Secretin

Question 50

How do enterocytes absorb nutrients

Answer 50

Secrete water, then reabsorb water with digestion products