CNS untested

• circadian rhythm is endogenous: controlled by an internal clock rather than simply responding to environment
• what are the genes involved in circadian rhythm in humans?

  per, cry, clk, bmal1, ck1e
• in humans, per and cry bind to form a dimer
• ghrelin is a hunger hormone that stimulates feeding
• Arc-POMC promotes the sympathetic system to inhibit feeding
• hormone downstream of Arc-POMC are?


  PVH, VMH, DMH
• which hormones downstream of Arc-POMC are inhibitory?

  DMH (だめ=inhibit）
• what are the hormones downstream of Arc-NPY?

  PVN and LH
• what is the signal to end a meal?

  blood glucose levels and sensors that measure stretch in the stomach
• how do internal clocks keep in check in the SCN?

  reset by light: signal from melanopsin retinal ganglion cells
• what's the origin and role of melatonin?

  released from the pineal body

  resets the master clock towards night
• how does the PER/CRY thing work?

  per and cry genes code for the PER and CRY proteins, but the PER and CRY protein dimer inhibits transcription of the genes, which leads to decrease in the proteins themselves
• CLK/BMAL1 dimer stimulates the transcription of per and cry genes, but they are inhibited by the PER/CRY dimer
• 2 hormones related to sleep and their relationship with each other?

  orexin (day) and melatonin concentrating hormone (MCH)

  they inhibit each other
• what is the phenomenon when you touch something so hot (over 45c) and it feels cold for a moment?

  paradoxical cold
• nociceptive signaling: the fast fibers are alpha-delta, slow fibers are C fibers
• alpha-beta fibers can reduce pain signals by c fibers
• vestibular: relating to balance
• types of hearing loss and whats wrong?

  1. Conductive hearing loss: Problem with the outer or middle ear that blocks sound from reaching the inner ear 2. Sensorineural hearing loss: Damage to the inner ear and hair cells 3. Central hearing loss: Problem with the cortex and processing
• 2 types of hearing tests?

  Rinne test and Weber test
• Rinne test: comparing between ear canal and skull, for conductive hearing loss
• Weber test: louder in good ear = sennsorineural, louder in bad ear=conductive
• ATP breakdown leads to adenosine builds up during the day, ad during sleep ATP levels are restored and adenosine levels fall
• presbyopia is caused by the lens becoming more stiff as we age