Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
10 Cards in this Set
- Front
- Back
|
circadian rythm
|
about a day
|
|
|
free-running vs. entraining the rythm
|
free running - clock shifts to the right
entraining the clock - locks back on to natural biological clock again *doesn't repsond to external cues |
|
|
terminology
|
free run - absense of external cues and the clock still goes
entrain - lock onto specific time -zeitgeber - cue that entrains -temp insensitivity - not dependent upon temperature |
|
|
how do most animals best free-run?
|
in total darkness
|
|
|
Where is the clock?
|
mammals - SCN
fish/reptiles - pineal gland insects - brain |
|
|
SCN
|
communicates via hormones, doesn't have to be connected
|
|
|
Period Genes:
|
per(+) -> wild-type(24 hr)
per(s) -> period short(9hr) per(Li) -> period long (29 hr) per(o) -> no period(random) |
|
|
Explain Jet Lag
|
SCN adjusts in one day but there's a seperate clock in lungs/liver/muscle that takes longer to adjust. one solution: start eating on destination time days in advance
|
|
|
transcriptional clock
|
genetic clock that relies on DNA transcription. Period protein shuts off period gene over a 24-hr. rythym
-doubletime breaks down per. protein -cryptochrome activated by the sun and detroys per/tim dimers |
|
|
circannual rythm
|
an annual rythym. when isolate organism, rythym drifts to the left
|
