Lecture 5 Part 2

Question 1

what are ways to describe a hormone

Answer 1

1. composition
2. source
3. stimulus
4. target
5. action

Question 2

what is a hormone

Answer 2

substance secreted from ductless gland from source to target tissue

Question 3

when you eat something, what will most likely be produced

Answer 3

gastrin

Question 4

gastrin

Answer 4

1. composition: polypeptide
2. source: gastric mucosa
3. stimuli: stomach distention, dietary proteins, fats, carbs, alcohol and caffeine, vagus nerve
4. target: gastric glands
5. action: secretion of HCl and pepsin

Question 5

gastric mucosa

Answer 5

stomach lining

Question 6

stomach distention

Answer 6

causes stretching
- when you eat something

Question 7

what causes the most stimulation of gastrin

Answer 7

dietary proteins

Question 8

what is vagus nerve stimulation

Answer 8

• stimulated when you eat
• most closely interacted nerve of gastro intestinal system

Question 9

what inhibits gastrin production

Answer 9

acid feedback
- negative feedback system
- HCl raises because gastrin stimulates it
- negative feedback regulates this action so don’t burn hole in stomach

Question 10

pepsin

Answer 10

breaks down peptide bonds

Question 11

vagus nerve and gastrin relationship

Answer 11

• parallel pathways
• vagus nerve stimulates HCl and pepsin
• vagus nerve turns on gastrin

Question 12

what is the difference between vagus stimulation and gastrin production

Answer 12

vagus stimulation is short term (immediate) and gastrin production is long term

Question 13

secretin

Answer 13

1. composition: polypeptide
2. source: SI mucosa
3. stimuli: presence in SI of Hcl, polypeptides of dietary origin
4. target: pancreas
5. action: secretion of water and bicarbonate (pancreatic and bile)

Question 14

what does the action of secretin do

Answer 14

• secretion of water
• secretion of bicarbonate
• neutralizes gastric acid
• adds liquid to lumen

Question 15

CCK

Answer 15

cholecystokinin

Question 16

what is another name for cholecystokinin (CCK)

Answer 16

pancreozymin

Question 17

CCK

Answer 17

1. composition: polypeptide
2. source: SI mucosa and brain
3. stimulus: presence in SI of peptides and fats
4. target: several organs and tissues
5. multiple actions (another slide for this)

Question 18

SI mucosa

Answer 18

small intestine lining

Question 19

action of CCK

Answer 19

• empties gall bladder
• stimulates synthesis of pancreatic enzymes
• inhibits HCL
• delays gastric emptying
• regulates blood glucose
• produces satiety

Question 20

how does CCK empty the gall bladder

Answer 20

contracts gall bladder and pancreas
- bile helps break down

Question 21

why would CCK be beneficial in slowing gastric emptying

Answer 21

• slows down food briefly
• want to give time for enzymes to work

Question 22

how is the regulation of blood glucose from CCK helpful

Answer 22

enhances insulin release

Question 23

what does producing satiety do

Answer 23

provides feeling of being full/not hungry

Question 24

why do dietary fats and fiber delay gastric emptying

Answer 24

• these usually take longer to digest
• allows for more time to for digestion in SI
• effect of this may be medicated by CCK

Question 25

what is the meaning of GIP

Answer 25

gastric inhibitory polypeptide

Question 26

GIP

Answer 26

1. composition: polypeptide 2. source: duodenum (small intestine) 3. stimulus: presence in SI of fats, glucose, and bile 4. target: stomach 5. action: HCl production and gastric mobility

Question 27

what do fats do

Answer 27

stimulate release of fats

Question 28

what is the main action of GIP

Answer 28

HCl production

Question 29

motilin

Answer 29

1. composition: polypeptide 2. source: duodenum and jejunum (small intestine) 3. stimulus: will vary (on other cards) 4. target: entire GIT 5. action: housekeeping during fasting (90-100 minutes) and stimulates gastric motor activity

Question 30

what are the stimulus of motilin

Answer 30

- nerve stimulus - species differences between meal stimulus (fats and proteins)

Question 31

how does motilin perform "housekeeping"

Answer 31

- pattern - sweeping/moving food through intestinal track so it doesn't just sit - cause contractions of intestine

Question 32

somatostatin

Answer 32

- master controller - secreted at end 1. composition: polypeptide 2. source: abomasal antrum, duodenum, nerve cells in GIT 3. stimulus: vagal stimulation 4. target: pancreas 5. action: turn off all other GIT hormones

Question 33

what are some of the actions of somatostatin

Answer 33

turn of all other GIT hormones by inhibiting the following: - acid production - gastrin - secretion - CCK - GIP - motilin - ion transport in intestines