Exam 4 Flashcards
Biorhythm
Cyclical changes in behavior or bodily functions
Zeitgeber
a clock-setting cue
Entrainment
when a biorhythm is reset by a zeitgeber
Free-running rhythm
cycle that has a period of the body’s own devising
Jet lag
disruption of the body’s circadian phase
Circannual
yearly biorhythm (ex: migratory cycle of birds)
Circadian
daily biorhythm (ex: human sleep-wake cycle)
Ultradian
less than a day biorhythm (ex: human eating cycles)
Infradian
more than a day biorhythm (ex: human menstrual cycle)
Suprachiasmatic nucleus
master biological clock, mostly responsible for maintaining Circadian rhythms
Where is Suprachiasmatic nucleus located and what larger structure is it a part of?
It is located in the Hypothalmus and is part of the retinohypothalmic pathway
How do light signals (melanopsin photopigment signals) get from the retina to the SCN of the hypothalmus?
Light activates a special group of photoreceptors in the retina that send melanospin photopigment signals, via the retinal hypothalmic pathway (respond more slowly to light)
The pineal gland is an endocrine gland that produces the neurohormone melatonin at night.
In what situation mght taking a melatonin supplement be helpful?
Taking melatonin can help with insomnia. Taking it in the afternoon can phase-advance the biological clock, which can help relieve some jet lag.
What is the difference between advanced sleep phase disorder and delayed sleep phase disorder?
Advanced sleep phase disorder is when your rhythm makes you go to bed earlier while Delayed sleep phase disorder is when your rhythm you go to bed later
List interruptions of consciousness
Coma, vegetative state, minimally conscious state, and brain death
Coma
extended period of unsciousness caused by head trauma, stroke, or disease characterized by low brain activity that remains fairly steady
Vegetative state
person alternates between periods of sleep and moderate arousal but no awareness of surrounding
Minimally conscious state
one stage higher than a vegetative state marked by occassional brief periods of purposeful action and limited speech comprehension
Brain death
no sign of brain activity and no response to stimulus
Why do we sleep?
Conservation of energy, repair & restoration (release growth hormone to repair tissue), and learning & memory consolidation
Who sleeps more predator or prey?
Predatory animals sleep more than prey
When is human body temperature lowest during a 24-hour cycle?
Human termperature is lowest at 4:30 Am
What are growth hormones good for (besides growth) and when are they released during the 24-hour cycle?
Growth hormones are also good for regeneration of tissue, secreted during sleep
What tools do we use to measure that activity of the brain and body during sleep?
Polysomnograph
Electroencephalogram (EEG)
Electromyogram (EMG)
Electroculogram (EOG)