Obesity Flashcards
What controls appetite regulation
peripheral hormones and neural signals that interact with the CNS appetite circuits
In what ways do messages from the periphery reach the brain
circulation: products cross the blood-brain barrier
neural circuits: vagal afferents from GI tract
What produces leptin and what is the function of leptin
Adipocytes (fat cells)
It signals to the brain about the quantity of fat stored
It indicates whether fat stores are sufficient for survival and reproduction
Where is ghrelin produced and what does it do
peptide produced in the stomach that increases food intake and stimulates GH
What parts of the CNS are important in the regulation of appetite
Nucleus of the tracts solitaires
Arcuate nucleus (base of hypothalamus)
Paraventricular nucleus
What does damage to the ventromedial hypothalamus lead to
increased food intake and obesity
What does damage to the lateral hypothalamus lead to
reduced food intake and lower body weight
What disorders is obesity linked with
insulin resistance diabetes mellitus hypertension dyslipidaemia coronary heart disease stroke sleep apnoea cancer
How is obesity defined
BMI of 30+
What BMI signals overweight
25-29.9
Describe the link between ethnicity and sex
White men are more likely to be obese than black men
Black women are more likely to be obese than white women
What are some causes of obesity
Lifestyle and social Dietary factors genetic factors drugs neuroendocrine disorders prenatal factors psychological factors
What is the most common monogenic cause of obesity in childhood
Heterozygous mutations in the gene encoding the Melanocortin-4 receptor
What gene mutation increases the risk of obesity in the general population
A variant in the FTO gene (fat mass and obesity associated) on chromosome 16
What sorts of drugs can cause weight gain
atypical antipsychotics tricyclic antidepressants anti epileptic drugs insulin sulphonylureas thiazolidinediones glucocorticoids