Obesity and Meta Syndrome Flashcards
where are the hunger and satiety centres
hypothalamus
where from the body do you get the don’t eat signals
circulating hormones and gut signals
what is the structure and role of ghrelin
28 aa peptide from neuroendorcrone cells in the stomach
released when stomach is empty - powerful hypothalamic orexigenic agent - ie makes you hungry
what is an anorexigenic and what are some examples
suppress hunger CCK insulin GLP-1 peptide yy somatostatin oxyntomodulin
what is the role of leptin
long term alteration of food intake and energy exposure - comes from adipocytes
what pathway do anorexigens reach the brain
via the nucleus of the solitary tract in the medulla
the arcuate nucleus in the hypothalamus sends projections to…
satiety centre in the ventromedial nucleus
hunger centre in the later hypothalamic area
what two types of neurones are present in the arcuate nucleus
anorexigenic
orexigenic
what do anorexigenic neurones secrete
proopiomelanocortin (POMC) and cocaine amphetamine related trasncript (CART)
what do oreigenic neurones secrete
agouti-related peptide (AGRP) and neuropeptide Y
what does AGRP inhibit
melanocortin receptors
what physiological consequences occur do to extreme starvation
muscle wasting fatigue diminished respiratory capacity slowed heart rate loss of heat generation apathy death from respiratory or cardiac failure or infection
describe what anorexia nervosa is
body weight more than 15% below standard ie BMI less than 17.5
voluntary weight loss
distorted body image
amenorrhoea in women
what are the life treating association with anorexia nervosa
2-5% suicide risk or die of starvation
what is bulimia nervosa
without low body weight but similar to anorexia - common in american college girls
what are the classes of BMI
underweight less than 18.5
normal 18.5-24.99
overweight 25-25.99
obese more than 30
what is a high BMI more commonly associated with
type 2 diabetes
what is a very small fraction of obesity caused by
genetic defects altering leptin and ghrelin
what are some of the physiological consequences of obesity
osteoarthritis hypertension/DVT T2 diabetes cancers erectile dysfunction and female infertility sleep apnoea NAFLD stress, low self esteem etc
what must you have a combination of to have metabolic syndrome
3 out of 5 of obesity T2 DM hypertension High plasma triglycerides low HDL cholesterol
what causes the lipid overflow ectopic fat model
positive energy balance from low exercise and high fat diet
can lead to good fat ( subcutaneous) but also to visceral fat which alters FFA metabolism and release of adipokines
what is a hyperlipolytic state
high amount of visceral fat which produces more non-esterified fatty acids (NEFA)
in turn makes you less sensitive to insulin and impairs insulin release from B cells
what does high insulin resistance causes
high plasma insulin and higher plasma glucose which induce an inflammatory response and production of ROS
a combination of dyslipidaemia and ROS is thought to underly which conditions
atheroma and CVD
