Exam 4 study guide Sleep 1 What does it mean for a pattern of behavior to have an endogenous circadian rhythm What influence do zeitgebers have on these cycles Give an example of how behavior can be disrupted in their absence What brain area is necessary for the generation of endogenous cycles In what specific way does it receive input Describe the cycles of two proteins and one hormone associated with biological clock regulation Differentiate between sleep and coma Define the stages of sleep What dos the slowing of brain waves as sleep progresses indicate How is REM sleep paradoxical Behavioral Cycles a cycle Endogenous rhythms internally generated signals that prepare behaviors that occur on Circannual annually migration hibernation animals Circadian Daily sleep eating Zeitgebers stimuli that typically cycle with our rhythms light outside temperature outside etc Can be interrupted by visual impairments and lifestyle changes like overseas flying and night jobs Biological Clocks humans Genetics of Bio Clocks Superchiasmatic nucleus SCN Portion of the hypothalamus just above the optic Chiasm SCN receives info directly via optic nerve which is why light is the primary zeitgeber in Retinal ganglion cells containing photopigment melanopsin compose this portion of the optic nerve Optic nerve with melanopsin SCN Fluctuation of 2 genetically expressed proteins over the day promotes sleep wakefulness Feedback cycle between mRNA and protein production takes 24 hours Proteins also broken down due to light SCN controls the pineal gland which releases melatonin that is produced at night to promote sleepiness Characterizations of Sleep Inactivity Minimal response to stimuli Slowed brain activity Cycles back into wakefulness in a reasonable amount of time What Sleep Isnt Stages Of Sleep Vegetative State alternation of sleep and arousal but arousal and brain activity is limited Coma little brain activity coupled with barely any responsiveness to stimuli Brain Death No brain activity no response to stimuli Sleep and arousal defined by their associated patterns of brain activity Wakefulness steady relatively high frequency of alpha waves Stage 1 irregular waves with lower amplitude Stage 2 emergence of Sleep Spindles and k complexes Slow Wave stages 3 4 lower frequency waves REM Sleep Brain activity similar to stage 1 Muscles completely relaxed to point of paralysis although autonomic functioning increases Some facial twitching and eye movement in humans Often associated with vivid reaming but not necessary for REM sleep Sleep 2 List the areas of the brain involved in arousal and wakefulness and the neurotransmitters that they signal with What is the main neurotransmitter that maintains sleep How can a practitioner diagnose insomnia What is lack of sleep associated with Describe two conditions that are caused by interrupted sleep What functions might sleep play What about dreaming Brain structures implicated in sleep arousal Reticular formation projection of neurons from medulla that ascend to the forebrain or descend to spinal cord Pontomesencephalon nuclei in pons that generate spontaneous activity as well as receive info from senses these messages are distributed to the cortex to promote wakefulness Uses acetylcholine and glutamate as NTs Locus Coeruleus nuclei in pons that projects widely through cortex Signal in response to meaningful events especially those associated with emotion Increase wakefulness and strengthens storage of recent memories Uses norepinephrine as NT Hypothalamic Pathways Histaminergic active during arousal and alertness Orexigenic Hypocretinergic necessary for staying awake but not for waking up Basal Forebrain pathways Controlled by hypothalamus Acetylcholinergic increase attention and shift from non REM to REM sleep GABAergic decrease alertness through inhibition of cortex and thalamus Dorsal Raphe nuclei in pons that project widely through the cortex Transition out of REM sleep Uses serotonin as NT GABA responsible for Sleep GABA mediate inhibition doesn t stop neurons from responding to stimuli but hinders the message from moving on Sleepwalking lucid dreams and hypnogogic hallucinations are also examples Sleep Disorders 7 5 9 hours considered normal 7 6 is avg for an adult with children 8 6 for college student Insomnia inability to fall asleep or stay asleep defined on impact on daily life Sleep Apnea impaired ability to breathe during sleeping Lack of oxygen leads to neuronal death and cognitive defects sleep apne has a genetic basis but can be treated with surgery or a Continuous Positive Airway Pressure Machine Narcolepsy sudden attacks of extreme sleepiness during the day May include Cataplexy a loss of muscle tone usually in response to high arousal Has some genetic basis but seems to be directly caused by the lack of hypothalamic cells that produce Orexin Treated with stimulants like Ritalin Functions of Sleep Energy conservation decreased risk of predation Memory consolidation and synaptic pruning REM associated with motor learning nonREM associated with Verbal Learning Functions of Dreaming Activation synthesis hypothesis dreaming is your brains way of making sense of random bursts of brain activity Clinico anatomical hypothesis dreaming is your brains reaction to not having to constantly deal with input from senses Thirst 1 Describe the main components of a homeostatic system Why does fluid balance need to be so tightly controlled What causes the two types of thirst In which do you need both fluid and salt How does ADH help re regulate both situations What do angiotensin II and aldosterone each do When combined what type of behavior do they induce Homeostatic Regulation All chemical process necessary for life take place in solution making fluid regulation essential Very tightly controlled homeostatic mechanism attempt to keep a certain variable at a set point through use of neg feedback Different situation motivate thirst Osmotic thirst increased salt content of extracellular fluid Increases Osmotic pressure drawing fluids out of cells Dilute extracellular fluid by drinking water and kidneys excrete urine more concentrated with salt Hypovolemic thirst fluid loss bleeding sweating diarrhea Not enough fluid to sustain blood pressure and heart function Also need to restore lost salts to regulate osmotic pressure Brain Mechanisms implicated in Osmotic Thirst Receptors in the OVLT and SFO detect changes in Osmotic pressure across their membrane These
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