Regulation of GI functions

Question 1

What are the 4 functional layers of the GI tract

Answer 1

Mucosa
Submucosa
Muscularis
Serosa

Question 2

Which plexus is found in the submucosa

Answer 2

Submucosal plexus

Question 3

Which plexus is found in the muscularis

Answer 3

Myenteric plexus

Question 4

Another name for Submucosa plexus

Answer 4

Meissner’s plexus

Question 5

Another name for Myenteric plexus

Answer 5

Auerbach’s plexus

Question 6

Function of the submucosa plexus

Answer 6

Glandular secretion

Question 7

Function of the myenteric plexus

Answer 7

Muscle movement

Question 8

What are the two types of GI tract innervation?

Answer 8

Intrinsic vs. extrinsic

Question 9

What is the intrinsic innervation of the GI tract?

Answer 9

Enteric Nervous System

Question 10

Epigastric visceral pain

Answer 10

T7-T8. pain from stomach and small intestine

Question 11

Periumbilical visceral pain

Answer 11

T10, pain from distal small intestine and proximal colon

Question 12

Groin Visceral Pain

Answer 12

L1, pain from large distal large intestine and rectum

Question 13

Preganglionic neurons are always______ and utilize ______ receptors

Answer 13

Cholinergic (Ach) and nicotinic Ach receptors

Question 14

Postganglionic PSNS neurons utilize _____ and _____ receptors

Answer 14

Ach and muscarinic Ach receptros

Question 15

Postganglionic SNS neurons utilize _____ and ____ receptors

Answer 15

NE and adrenergic receptors

Question 16

Postganglionic neurons to sweat glands utilize _____

Answer 16

Ach

Question 17

Adrenal medulla secretes

Answer 17

Epi

Question 18

Actelycholine _____ smooth muscle, _____ internal sphincter, and ______ salivary, gastric and pancreatic secretions

Answer 18

Contracts
Relaxes
increases

Question 19

Norepinephrine _____ smooth muscle, _____ internal sphincters, and _____ watery glandular secretions

Answer 19

Relaxes
contracts
reduces

Question 20

Is somatostatin an endocrine, paracrine, autocrine, or neurocrine substance?

Answer 20

TRICK QUESTION! Endocrine (delta cells of pancreas) and paracrine (antrum of stomach controlling G cell)

Question 21

Vasoactive intestinal peptide _____ smooth muscle but _____ salivary, gastric, and pancreatic secretion.

Answer 21

Relaxes

Increases

Question 22

Substance P is co-secreted with _____ and _____ smooth muscle and _____ salivary gland secretions.

Answer 22

Ach
Contracts
Increases

Question 23

Enkephalins (opiates) _____ smooth muscle and sphincter and _____ glandular secretions

Answer 23

Contracts

reduces

Question 24

Opiates cause ____ because they disrupt normal contraction and relaxation cycles

Answer 24

Constipation

Question 25

Neuropeptide Y _____ smooth muscle and _____ glandular secretion

Answer 25

Relaxes | Reduces

Question 26

Gastrin-releasing peptide (GRP) _____ gastrin secretion

Answer 26

Increases

Question 27

Gastrin is secreted by

Answer 27

G cells in antrum of stomach and duodenum.

Question 28

Gastrin is structurally related to

Answer 28

CCK

Question 29

Gastrin _____ gastric H+ secretion, _____ gastric mucosa, and ____ gastric motility

Answer 29

Increase grow Increase

Question 30

What stimulates gastrin secretion?

Answer 30

Dietary peptides and vagal stimulation

Question 31

Vagal innervation of G cell uses

Answer 31

Gastrin-releasing peptides (GRP)

Question 32

Acid in antrum stimulates

Answer 32

D cells

Question 33

D cells secrete

Answer 33

Somatostatin

Question 34

Somatostatin

Answer 34

inhibits G cells by paracrine action

Question 35

Gastrin binds to ____ receptors on ____ cell in the _____ of the stomach.

Answer 35

CCKb receptors Parietal cells Fundus

Question 36

Which pathway of gastrin action is more powerful?

Answer 36

Indirect

Question 37

Gastrin indirect pathway

Answer 37

Gastrin stimulates ECL cells to release histamine which activates parietal cells.

Question 38

Two classes of medicine to reduce stomach acid

Answer 38

H2 blockers | Proton-pump inhibitors

Question 39

CCKA are selective for _____ while CCKB bind _____

Answer 39

CCK | CCK and Gastrin (mostly gastrin)

Question 40

CCK is secreted from _____ cells in ______

Answer 40

I cells | Duodenum and Jejunum

Question 41

CCK is released in response to _____ and ____

Answer 41

Fat and protein

Question 42

CCK _____ gall bladder, ______ sphincter of Oddi, ____ secretion of primarily enzymes from exocrine pancreas and ______ gastric emptying

Answer 42

Contracts Relaxes Stimulates Inhibits

Question 43

Secretin is secreted from _____ cells in ______

Answer 43

S cells in duodenum and jejunum

Question 44

Secretin is secreted in response to _____ and _____

Answer 44

H+ and fatty acids

Question 45

Secretin _____ secretion of HCO3- from pancreas and bile

Answer 45

Promotes

Question 46

Pancreatic Lipases are denatured by

Answer 46

Low pH

Question 47

Incretins are secreted in response to

Answer 47

glucose, protein, or fat load.

Question 48

Incretins relation to insulin

Answer 48

augments insulin release from pancreatic beta cell but only in presence of glucose.

Question 49

Main incretins are

Answer 49

GLP-1 and GIP

Question 50

GIP is secreted from

Answer 50

K cells in duodenum

Question 51

GLP-1 is secreted from

Answer 51

L cells in ileum and colon.

Question 52

Local reflexes of GI

Answer 52

Entirely within ENS. These reflexes control secretions, peristalsis, and mixing contractions.

Question 53

Gastrocolic reflex

Answer 53

Signals from stomach to cause evacuation of the colon.

Question 54

Enterogastric reflex

Answer 54

Signals from small intestine inhibit stomach motility and stomach secretion.

Question 55

Colonoileal reflex

Answer 55

Signals from colon inhibit emptying of ileal contents into the colon.

Question 56

Positive hypothalamic input (2 factors)

Answer 56

1) appetizing sight/smell/taste of food signals from cerebral cortex. 2) Gherkin from an empty stomach

Question 57

Negative hypothalamic input (3 factors)

Answer 57

1) Afferents from stomach relaying fullness 2) Gastrointestinal hormones - insulin, PYY, CCK 3) Adipose tissue - Leptin