Regulation of Feeding

Question 1

2 things that drive us to eat (or not)

Answer 1

1. hunger

2. appetite

Question 2

a biological drive controlled by the internal body mechanisms

Answer 2

hunger

Question 3

2 types of hunger

Answer 3

• neural

- appetite

Question 4

psychological drive affected by external food choice mechanisms

Answer 4

appetite

Question 5

if you smell something yummy, and want to eat it. is this hunger or appetite?

Answer 5

appetite

Question 6

what brain part is the “feeding center” and the “satiety center”

Answer 6

hypothalamus

Question 7

what brain part regulates food behaviour and integrates senses

Answer 7

hypothalamus

Question 8

two type of signals feeding the hypothalamus

Answer 8

• endocrine (blood) signal

- neural signal (direct form the gut to the hypothalamus)

Question 9

a process that promotes meal termination thereby limiting meal size

Answer 9

satiation

Question 10

satiation results from a coordinated series of neural and hormonal signals that emanate from the gut in response to ? and ? properties of ingested food.

Answer 10

mechanical and chemical

Question 11

when we feel full are we actually full?

why not?

Answer 11

NO. humans and animal can actually eat way more than we do.

–> satiation kicks in to prevent overconsumption during individual meals.

Question 12

what happens if satiation does not kick in and we ate tooo much

Answer 12

• consequences from incomplete digestion (cannot absorb all the nutrients so we just excrete them)
• excessive disturbances in circulating levels of glucose and other nutrients

Question 13

why is disturbances in glucose bad?

Answer 13

excessive amounts of glucose disrupts the system b/c we have limited ability to store it

Question 14

what can happen to some minerals if they are over consumed?

Answer 14

they can become toxic

Question 15

the process of breaking large food molecules down to smaller molecules

Answer 15

digestion

Question 16

2 types of digestion

Answer 16

1. mechanical digestion (the physical breakdown)

2. chemical (enzymatic reactions that break down food)

Question 17

the process of taking molecules across a cell membrane and into cells of the body.

Answer 17

absorption

Question 18

during absorption, nutrients are taken up by ? and ? for distribution of body cells for use or storage

Answer 18

• lympth (fats) system

- Circulatory (CHO & Protein) systems

Question 19

what % of each CHO, protein and fats that we consume are digested and absorbed

Answer 19

• 99% CHO
• 92% protein
• 95% fats

Question 20

mouth function

Answer 20

mechanical digestion

Question 21

salivary glands function

Answer 21

secretion of fluid and digestive enzymes

Question 22

stomach function

Answer 22

secretion of HCl and protein digesting enzymes (proteases)

Question 23

pancreas function

Answer 23

secretion of NaHCO3 and digestive enzymes

Question 24

liver function

Answer 24

secretion of bile acids

Question 25

gall bladder function

Answer 25

temporary storage and concentration of bile

Question 26

small intestine function

Answer 26

digestion of food, absorption, nutrients, and electrolytes

Question 27

large intestine function

Answer 27

absorption of electrolytes and water

Question 28

3 functions of chewing

Answer 28

1. break down food into smaller pieces 2. saliva starts a chemical process (amylase) 3. breaks down CHO

Question 29

95% of absorption is in?

Answer 29

the small intestine

Question 30

what parts related in digestion are not under the vagus nerve control? (voluntary control)

Answer 30

distal parts of large intestine

Question 31

the stomach controls the release of its contents so we can ?

Answer 31

neutralize the acid properly and not overwhelm the intestines

Question 32

what is the gastric emptying rate?

Answer 32

200-1000ml per hour | or 1 L at a time

Question 33

how many L can stomach stretch too

Answer 33

6L !

Question 34

the regulation of gastric emptying uses what mechanisms?

Answer 34

feed forward and feed back

Question 35

factors that effect emptying rate

Answer 35

everything. see slide and image

Question 36

if you have lots of fat or more than 1% of CHO being digested what will happen?

Answer 36

emptying slows (they require more enzymes from the pancreas)

Question 37

where does 90% of all absorption occur?

Answer 37

small intestine

Question 38

3 divisions of small intestine and there length

Answer 38

duodenum (30cm) jejunum (1-2m) ileum (1m)

Question 39

the ileum works to ? the rest of the divisions

Answer 39

SLOW

Question 40

how long does it take our food to get out of our system? and how long its it in the small intestine?

Answer 40

1-3 day transit time | - 3-10 hours

Question 41

peristalsis (rythmic contractions of sm int.) happens at what rate? and chyme flows at what rate?

Answer 41

0. 5-2cm/s | - 1cm/s

Question 42

what is the benefit of the fold in microvili and vili?

Answer 42

increase SA

Question 43

what % of villi actually act as an endocrine receptor

Answer 43

1% (largest functional part of the endocrine system)

Question 44

3 characteristics of Villi

Answer 44

1. highly vascularized 2. hepatic portal vein 3. lacteals

Question 45

what is the only excitatory GI peptide and where is it?

Answer 45

ghrelin in the stomach

Question 46

peptides of the stomach (3)

Answer 46

1. ghrelin 2. leptin 3. GRP, NMB

Question 47

peptides of the duodenum (1)

Answer 47

CCK

Question 48

peptides of the jejunum (1)

Answer 48

APO AIV

Question 49

Peptides of the ileum (3)

Answer 49

1. GLP1 2. Oxyntomodulin 3. PYY

Question 50

peptides of the pancreas (5)

Answer 50

1. amylin 2. enterostatin 3. glucagon 4. insulin 5. PP

Question 51

peptides of the colon (3)

Answer 51

1. GLP1 2. Oxyntomodulin 3. PYY

Question 52

how many enteric neurons in the feedback loop

Answer 52

200-600

Question 53

gastric satiation is primarily mechanical stimulus of vagus and ?

Answer 53

splanchnic nerves

Question 54

NT in gastric satiation (6)

Answer 54

1. glutamate, 2. acetylcholine, 3. nitric oxide, 4. calcitonin-­‐gene-­‐related pepdide, 5. substance P, 6. galanin

Question 55

3 functions of ghrelin

Answer 55

1. functions opposite to satiation peptides 2. powerfully increases food intake 3. marked pre-meal surges

Question 56

function of leptin

Answer 56

in response to lipids enhances CCK and GLP1

Question 57

leptin secretion will increase when you eat what?

Answer 57

fatty foods (response to lipids)

Question 58

leptin when enhance what peptides in response to leptin

Answer 58

CCK and GLP1

Question 59

what 3 things do you always want to think about when considering hormones?

Answer 59

1. what produced it 2. what is its target 3. what is its effect

Question 60

gastrin releasing peptide (GRP) and and neuromedin B (NMB) release ? and other digestive secretions in response to?

Answer 60

- gastrin | - mechanical stimulation of the stomach

Question 61

intestinal satiation is primarily ? or ?

Answer 61

chemical or nutritive

Question 62

why do most intestinal satiation signals inhibit gastric emptying

Answer 62

helps limit ingestion by enhancing gastric mechanoreceptor stimulation

Question 63

during intestinal satiation, peptides are secreted from ? cells in response to?

Answer 63

enteroendocrine cells, ingested food

Question 64

during intestinal satiation, the peptides then activate nearby nerve fibers and and/or ?

Answer 64

enter the blood stream to act as hormones

Question 65

the first neuro peptide to be released from the instestine is? and it does what?

Answer 65

CCK | - decreases activity of the distal stomach and relaxes the proximal stomach (slowing emptying) (reservoir)

Question 66

cholecystokinin (CCK) releases in response to?

Answer 66

lipids and protein

Question 67

apolopoprotein (APO AIV) releases in response to?

Answer 67

lipids

Question 68

glucagon like peptide 1 (GLP1) releases in response to?

Answer 68

lipids and CHO | it will inhibit gastric emptying and enhance CCK

Question 69

oxyntomodulin releases in response to?

Answer 69

caloric density (mainly fats)

Question 70

pancreatic polypeptide (PPY) releases in response to what ?

Answer 70

caloric density, | --> in order (fats, CHOs, protein)

Question 71

by slowing emptying we can promote?

Answer 71

more absorption

Question 72

3 examples of foods that are digested more easily

Answer 72

- fresh whole foods (fiber) - whole grain bread (fiber) - protein - -> FIBER!!!

Question 73

what happens when you overeat?

Answer 73

you decrease the emptying rate to 1-200 ml an hour