hunger and thirst

what are the chemicals for hunger?

• Ghrelin

• Leptin

• OEA

• CCK

• Peptide YY 

• GLP 1

what is ghrelin?

• (growling) responsible for feeling hunger (short term signal)

what is Leptin

• deals with satiety and long term signal (telling you you're  full and can hold off)

what is OEA?

• hormone that delays the next meal (activates after you just ate something) (doesn't care about size)

what is CCK ?

•  hormone responsible for limiting portion size 

what is peptide YY

• hormone released after meal to make you feel full 

what is GLP 1?

• makes you feel less hungry 

  • Ozempic is a GLP 1 agonist (increasing GLP1) 

what are the physiological things that deal with hunger?

• Lateral Hypothalamus

• Ventromedial hypothalamus

• Paraventricular Nucleus

• Arcuate Nucleus

what is the lateral hypothalamus?

• Facilitates feeding (says “start”) , alters taste, long term brain area saying we need to eat not 

  • If damaged = starve to death

what is the ventromedial hypothalamus

• long term/ Inhibits feeding/ Looks for fat storage and says you're good

  • Activating this area = loss in weight 

  • Deactivating this area= over eating

what is the paraventricular nucleus?

• deals with satiety by decreasing activation of lateral hypothalamus 

  • Turns off area that turns on you wanting to eat 

  • Makes you feel full 

what is the arcuate nucleus

• integrates all of this information 

  • Should we actually eat something yes/no? 

what nerves deal with hunger?

• vagus nerves

• splanchnic nerves

what are vagus nerves?

•  responsible for telling you your stomach has been stretched 

  • Short term : in this moment you ate too much 

what are Splanchnic nerves?

• tell us about nutrient content

  • You have only eat M&Ms eat a real meal 

• Effects of hormones and brain areas on hunger and satiety (basically do the in-class activity)

  • if you wanted to increase weight vs decrease weight what chemicals and physiological areas would you activate/deactivate?

for weight loss:

• Increase leptin, OEA, CCK, Peptide YY, and GLP.

  • Avoid increasing Ghrelin.

• Activate the ventromedial hypothalamus and deactivate the lateral hypothalamus.

• Stimulate the vagus nerves more.

for weight gain:

• Increase Ghrelin

• Deactivate the ventromedial hypothalamus

• activate the lateral hypothalamus.

• Reduce vagus nerve activity.

what types of thirst are there?

1. osmotic

2. hypovolemic

what is osmotic thirst?

• cause by having too much salt

what is hypovolemic thirst?

•  loss of fluid (sweating/vomiting) 

  1. Low blood volume triggers set of steps to feel thirst

  2. kidneys release renin  (starts the signaling that gets transferred up to the brian)

  3. Protein Angiotensin 1 is released into the bloodstream

  4. Converted to Angiotensin 2

  5. Angiotensin 2 is what makes the blood vessels constrict telling the brain you need to drink something