Hunger & Satiety Flashcards
The hunger and satiety centre of the brain is
hypothalamus
The only organ to secrete a hormone stimulating hunger is what and what does it secrete?
stomach - ghrelin
stimulates hypothalamus
Food in the intestine stimulates which hormones to suppress appetite
cholecystokinin (CKK)
PYY
CLP-1
What does adipose tissue secrete to inhibit appetite?
leptin in response to fat intake/storage
What does the pancreas secrete to inhibit appetite?
insulin in response to carb and protein intake
What is pernicious anaemia and what do the RBCs look like?
vitamin B12 deficiency causing megoblastic RBCs (large and immature) and a drop in RBC count
Treatment for pernicious anaemia?
vitamin B12 supplements
Causes of pernicious anaemia
PPI
Gastrectomy
Symptoms of iron deficiency anaemia?
SOB, paleness, fatigue
What is iron deficiency anaemia?
iron deficiency resulting in low haemoglobin, paler looking RBCs, and reduced RBC count
Causes of iron deficiency anaemia?
Iron malabsorption or insufficiency in diet, gastrectomy, PPIs
What happens in terms of pancreatic hormones in starvation?
Glucagon increases
Insulin decreases
What 2 processes does the increase in glucagon and decrease in insulin stimulate in starvation?
gluconeogenesis
ketogenesis
Besides glycogen break down, what are the sources used by the liver to make glucose in gluconeogenesis in starvation?
amino acids from protein breakdown in muscle
amino acids > glucose
Glycerol from triglyceride breakdown in adipose tissue
glycerol > glucose
Triglycerides are broken down to fatty acids and gycerol. Which processes are each of these products used in by the liver?
glycerol > glucose
fatty acids > ketone body
What happens to villi in starvation and what are the consequences?
Decreasing calorie intake decreases the rate of cell growth > villi are rebuilt less quickly – villus atrophy
Decreased surface area for absorption results in decreased absorption of nutrients
Leads to diarrhoea (steatorrhoea) → deficiencies and ↑malnourishment
Decreased intake of fat calories > decreased absorption of fat-soluble vitamins
Compare the effect of glucose and fructose on appetite
fructose doesn’t stimulate insulin secretion so you eat more.
glucose stimulates insulin secretion which suppresses appetite
fructose stimulates lipogenesis more than glucose
BMI =
mass (KG)/height (m2)
Height dependent measure of weight
Normal BMI
18.5-25
Overweight BMI
25-30
Obese BMI
> 30
Obesity is a condition of excessive body fat accumulation to an extent that increases the risk of complicating diseases, these include…
CVD Diabetes Cancer Hypertension Joint damage GORD PCOS Stroke Hyperlipidemia Fertility probelms ETC...
What are the limitations of BMI as a measure
Does not distinguish fat from lean tissue or water
Does not identify a particular site of fat accumulation – which can have serious metabolic consequences…
What is a method of visualizing body fat which separates body mass into fat-free and fat mass regions
Dual-energy X-ray absorptiometry (DEXA) scans
How does waist-hip ratio relate to health risks
Where fat is deposited in the body governs insulin sensitivity
Visceral adiposity (apple shaped person - more weight around the waist) puts you at greater risk of type II diabetes, hyperlipidaemia, hypertension, CVD than subcutaneous adiposity (pear shaped person - more weight around the hips)
What drug can be given to decrease calorie absorption in obese people?
Orlistat (inhibits pancreatic lipase)
What drug can be given to inhibit appetite in obese people?
Sibutramine (Merida) – acts on brain, inhibit neurotransmitter, suppress appetite
Aside from drugs what treatment options are available for obese people?
calorie restricted diet - low fat and carb
bariatric surgery
non-surgical - gastric balloon (obalon)
Via which routes can a patient be given oral supplementation (nutrient fluid in conjunction with meals)
Nutrition can be enteral (directly into GIT) or parenteral (via a vein)
