biological Rhythms Flashcards
What does Endogenous pacemaker mean?
Internal mechanism rhythms.
What are examples of Endogenous pacemakers?
-Biological clocks inside of our body, sch as Suprachiasmatic nucleus(scn).This lies n the hypothalamus, is the master clock. It controls biological rhythms.
What is Exogenous Zeitgebers?
External environment events. They influence biological rhythms. These can be described as external environmental events that are responsible for resting the biological clock of an organism.
What research supports that the SCN controls sleep cycle?
Decoursey destroyed SCN connections of 30 chipmunks and then returned them to their natural habitat. Their sleep/wake cycle disappeared. By the study significant proportions of chipmunks were killed by predators because they were awake and vulnerable to attack when they should of been asleep.
What are the issues of Decourseys experiment?
-It is not generalised this is because they are animals.
-Ethical issues-altering there brains and unnecessary damage which led to a lot of chipmunks dying.
What researched evidence supports endogenous pacemakers?
Bred ‘ mutant’ hamsters in a 20 hour sleep cycle. SCN cells from the foetal tissue of mutant hamsters were then transplanted into brains of normal hamsters.The normal displayed the same abnormal patterns of 20 hours showing that the SCN imposed it spatters onto the recipients brain.
What are the issues of Breds experiment?
It is not generalised because they are hamsters and there is a lot of hard to the hamsters.
What research evidence contradicts the role of exogenous zeitgebers
Innuit Indians who live in the Artic circle inhabit an environment that has hardly any darkness in summer and hardly any light in winter.
If the sleep waking cycle was primarily controlled by EZ’s they would tend to sleep a huge amount in winter -hardly summer. however it wasn’t the case-Had regular sleep patterns.
What are the issues with the Innuit Indians experiment?
it was a small sample
What research evidences supports the role of exogenous and informs us that shift work may not be the best for individuals health.
Boivin et al 1996 fount
-night works who engaged in shift work experiences a period of reduced concentration around 6 am meaning mistakes an accident are more likely to happen.
-3x more likely to develop heart disease than those who do not work shifts.
What are circadian rhythms?
about 24 hours. The sleep cycle is an example f circadian rhythm, which dictate when humans and animals should be asleep and awake.
