Biological Rhythms Flashcards
Zeitgebers
light, food, activity
Intrinsically photosensitive
retinal ganglion
Responsible for generating circadian rhythms
suprachiasmatic nucleus
Associated with AD PER2 mutations
Advanced sleep phase disorder
Process S
Homeostatic need for sleep
Process C
circadian drive for arousal
May be caused by ATP breakdown and adenosine signaling
Sleep deprivation
Autoimmune destruction of orexin neurons
Narcolepsy
excessive daytime sleepiness, cataplexy, hypnagogig hallucinations, sleep paralysis, disturbed nocturnal sleep
Narcolepsy
Cardinal feature is reduced need for sleep
Bipolar disorder
Intrameal process that leads to termination of food intake
Satiety
Satiation
Process that controls intermeal interval
Grams of food consumed/intermeal interval
Satiety ratio
Meal phase: smell, sight, appeal, flavor, texture
Cognitive sensory
Meal phase: oral metering (sensory contact), osmotic load, gastric stretch
Pre-absorptive
Meal phase: nutrient absorption, digestive efficiency, neuroendocrine (CCK, insulin, GLPI)
Post-absorptive
Functions of meals
- Modulate nutrient intake
- Social interaction
- Set circadian rhythms
Key hypothalamic player in feeding
Arcuate nucleus
Inhibits feeding via aMSH acting on MC4R –> suppress food intake
POMC
Common mutation in obesity
MC4R
Promotes feeding via blocking MC4 receptor, blocking aMSH action
AgRP (agouti-related peptide)
Release GABA to inhibit POMC neuron activity –> promote appetite
NPY
Produced in stomach, pancreas, excitatory to NPY
Ghrelin
Produced by adipose, excitatory to POMC, inhibitory to NPY
leptin
Produced by duodenum, excitatory to POMC
Cholecystokinin
Produced by pancreatic beta-cells, excitatory to POMC
Insulin
Modafinil can treat
Narcolepsy, Shift work disorder
Lisdexamfetamine can treat
Binge eating disorder
