Flashcards in MEH - Intro To Endocrinology Deck (40)
Where is the appetite control centre located?
In the hypothalamus
What is the appetite control centre composed of?
Clusters of neurones called 'nuclei' which make up the arcuate nucleus
What are the two types of primary neurone in the arcuate nucleus?
- stimulatory neurones, which contain neuropeptide Y (NPY) and Agoouti-related peptide (AgRP) and promote hunger
- inhibitory neurones, which contain pro-opiomelanocortin (POMC) which yields several neurotransmitters, including alpha-MSH and beta-endorphin and promote satiety
What do primary neurones synapse with?
Secondary neurones in other regions of the hypothalamus, and the signals are integrated to alter feeding behaviour
What is leptin released by?
Released into blood by adipocytes
How does leptin suppress appetite?
- stimulates inhibitory (POMC) neurones
- inhibits excitatory (AgRP/NPY) neurones in the arcuate nucleus
- induces expression of uncoupling proteins in mitochondria, so energy is dissipated as heat
What is the role of insulin in appetite regulation?
It suppresses appetite by similar mechanism as leptin
Where is amylin released from?
Peptide hormone secreted by beta cells in the pancreas
What are the roles of amylin?
Role not fully understood, but definitely suppresses appetite, decreases glucagon secretion and slows gastric emptying