Appetite and satiety Flashcards
What does satiety mean
Satiety
* The desire to limit further food intake after a meal
* After a meal – post-prandial or post-cibal
What does Orexigenic
Orexigenic
* Appetite increasing (hyperphagic)
What does Anorexigenic mean
Anorexigenic
* Satiating (hypophagic)
What is the definition of motivational salience
Motivational Salience
- cognitive process and a form of attention motivating an individual’s behavior towards or away from a particular object, perceived event or outcome
Explain ATP and how it is generated
- ATP is the energy currency of the cell
- ATP can’t be stored, it must be constantly generated to support all cellular processes
- ATP is generated from macronutrients
- ATP is generated by glycolysis and oxidative phosphorylation via the citric acid cycle (TCA - tricarboxylic acid cycle)
- Glucose can enter glycolysis, fats enter the TCA via β-oxidation, amino acids also enter the TCA via several pathways
- Macronutrients must also be stored
- Fats are the best store (fats store ~6x the amount of energy per weight compared with carbohydrate
How much energy can the Adult liver store
Adult liver can store ~ 120 g of glycogen = ~2,000 kJ
Explain the energy usage of the brain
Our Brain requires glucose for 50-80% of its energy needs
- Plasma concentrations of other energy sources are low
- Free fatty acids are poorly transported across the blood brain barrier
- Hypoglycemia can lead to coma and death
- Under fasting conditions (e.g. >10 hours after a meal) glucose is supplied via de-novo glucose synthesis
What is the usual blood glucose level
Blood glucose is typically controlled in a very tight range (3.9 – 5.6 mM)
What is the resting glucose consumption by all organs and tissues
Resting glucose consumption by all organs and tissues ~2-4 mg/kg/min
What nervous system is used in fasting
Sympathetic nervous system
What occurs in fasting
- Increased glucagon secretion
- Decreased secretion
- increased Lipolysis
- Increased HGP
- Decreased GIT activity
What occurs in the Fed state and what nervous system is involved
- The Parasympathetic
- Decreased gastric emptying
- Decreased glucagon secretion
- Increased insulin secretion
- Decreased HGP
- Increased GIT activity
What Hypothalamic structures are involved in metabolism, appetite and satiety
- ARC – arcuate nucleus
- DMH – dorsomedial hypothalamus
- VMH - ventromedial hypothalamus
- LH – lateral hypothalamus
- PVN – paraventricular nucleus
What Extrahypothalamic structures are involved in metabolism, appetite and satiety
- VTA – ventral tegmental area
- AMY – amygdala
- NTS – nucleus tractus solitarius
- DMV – dorsal motor nucleus of the vagus
- AP – area postrema
What is the release site and regulation of release of Insulin
The release site is Pancreatic β-cells
The regulation of release is ↑Glucose, acetylcholine, GLP-1, GIP
