Physiology of feeding and satiety Flashcards Preview

Gastro > Physiology of feeding and satiety > Flashcards

Flashcards in Physiology of feeding and satiety Deck (50)
Loading flashcards...
1

What is energy homeostasis?

Physiological process whereby energy intake is matched to energy expenditure over time

2

How is energy primarily stored?

Promotes body fuel stability

3

What leads to obesity

Accessible, tasty calorie dense food and sedentary lifestyle. This is due to a small constant mismatch between energy intake and energy expenditure

4

What are some consequences of metabolic stress?

Metabolic syndrome
central obesity
dyslipidemia
insulin resistance
type 2 diabetes
cardiovascular disease

5

At what BMI is a someone classified as overweight and then obese and morbidly obese?

Overweight = 25-29.9
Obese is 30-39.9
Morbidly obese is more than 40

6

What has a dramatic increase in obesity caused?

A global epidemic

7

Describe obesity as a general disorder

Not a single disorder, but a heterogeneous group of conditions with multiple causes

8

What are the major influencing factors on obesity

Genetics (fatness through susceptible genes) and environment (compare food in USA to Africa)

9

What are some of the consequences of obesity?

Stroke
respiratory disease (sleep apnoea)
Heart disease (lipids, diabetes, hypertension)
Gallbladder disease
Osteoarthritis
Dementia
NAFLD (fatty liver)
Diabetes
Cancer (uterus, breast, prostate, colon)

10

Name 3 reasons of why we need fat?

Energy storage
Prevention of starvation
Energy buffer during prolonged illness

11

why is obesity described as a disease of the brain?

Difficult to lose weight once gained
Increased body fat alters the brain function
Long term obesity induces brain re-programming
Your brain biews the extra weight (fat) as normal and dieting as a threat to the body's survival

12

How does the CNS influence energy balance and body weight?

Behaviour - feeding and physical activity
ANS activity - regulates energy expenditure
Neuroendocrine system - secretion of hormones

13

Where is the site of integration

The brain

14

What is the area responsible for control of energy intake and body weight?

Hypothalamus

15

Lesioning ventromedial hypothalamus causes what?

Obesity

16

Lesioning lateral hypothalamus causes what?

Leanness

17

What 3 basic concepts underlie the control of energy intake and body weight?

Satiety signalling (sensation of fullness generated during a meal between termination of one meal and the initiation of the next)
Adiposity negative feedback signalling (state of being obese)
Food reward

18

What happens to the satiation signals during a meal

They increase to limit the meal size

19

Where is Cholecystokinin (CCK) secreted?

From enteroendocrine cells in the duodenum and jejunum

20

How is the volume of CCK regulated?

It is released in proportion to lipids and proteins in a meal

21

Where is Peptide YY (PYY3-36) secreted?

From endocrine mucosal L cells of GI tract.

22

How are the levels of PYY3-36 monitored?

They increase rapidly pst prandially

23

What is the role of PYY

To inhibit gastric motility, slow emptying and reduce food intake

24

What is glucagon-like peptide 1 (GLP-1)

Product of pro-glucagon gene.

25

Where is GLP-1 released from?

L cells in response to food ingestion

26

What does GLP-1 do?

Inhibits gastric emptying and reduces food intake

27

Where is Oxyntomodulin (OXM) released from?

Oxyntic cells of the small intestine after a meal

28

How does OXM act?

Acts to suppress appetite - although the mechanism is unnclear

29

What is OXM

A product of pro-glucagon gene

30

What is obestatin

Peptide produced from the gene that encodes ghrelin

Decks in Gastro Class (67):