Lecture 8.2 Flashcards
What are types of stored absorbed nutrients within the body, are they limited or unlimited and where are they stored?
Glycogen, limited and stored within the liver and skeletal muscle
Triglycerides, stored as fat, not limited
What are some types of absorbed nutrients that are used straight away?
Glucose, Fatty acids, Ketones
Describe the locations of the PVN, Lateral hypothalamic area (LHA), Ventromedial hypothalamus and arcuate nucleus in relation to the 3rd ventricle
PVN, LHA, Ventromedial hypothalamus just under the LHA and arcuate nucleus at the bottom
What does a lesion of the lateral hypothalamus cause?
Underweight specimen
What does a lesion of the ventromedial hypothalamus cause?
Overweight specimen
What are the 2 types of neurons within the Ventromedial hypothalamus and what do they produce/stimulate?
POMC neurons-alphaMSH-PVN, ANS, LHA
NPY/AgRP neurons- PVN, LHA
What receptors bind to alpha MSH?
MC 3 and 4
What type of receptors are the MC 3 and 4 receptors
GPCR
Describe the pathways that alpha MSH effects (3 pathways)
alphaMSH acts on PVN by acting on the anterior pituitary, this increases the release of ACTH and Thyrotropin, this leads to an increase in coritsol release thus regulating metabolic rate
alphaMSH also acts on the PVN to the ANS, this activates sympathetic neurons to increase activation of brown fat, thus increasing heat and increasing the rate of energy that is released
alphaMSH also inhibits feeding behaviours in the LHA
What do all the effects of alphaMSH produce?
A decrease in body weight
Describe the pathways that NPY/AgRP neurons take and what do they effect? (2 pathways)
These neurons project to PVN and decrease the secretion of hormones controlling ACTH
Also stimulates feeding behaviour in LHA
What do the effects of NPY/AgRP neurons produce?
An increase in body weight
What is Leptin and what does it do?
It is ahormond that signals a decrease in food intake
What does Leptin do to alphaMSH and NPY neurons?
Leptin stimulates alphaMSH to decrease food intake and inhibits NPY neurons
Why if Leptin is linear with fat, why are people fat?
People get fat due to a Leptin resistance in the body thus allowing for no trigger to say, that is enough