Biological Rythms Flashcards
What are biological rythms
Cyclic variations in bodily processes/physiology over time to maintain processes
What are Circadian Rythms
Rythms that occur every 24 hours, tell our bodies when to eat, sleep, secrete hormones etc.
E.G- Sleep/wake cycle
What are endogenos pacemakers?
Internal mechanisms which reguate bodily rythms and ensure they occur at a consistent time every 24 hours
What are exogenus zietgibers?
External environmental cues that synchronise the body clock with the environment for peak performance
What is the role of EZS and EPS in the sleep wake cycle
Endogenus pacemaker for the sleep wake cycle is located in the hypothalamus and is called the superchiasmatic nucleus, it signals to the pineal gland to release melatonin to induce sleep when its dark and signals to inhibit melatonin when it detects light to regulate the sleep wake cycle. Light is the main exogenus zietgiber in the sleep wake cycle- it synchronises the EP to the environment for peak performance and ensures it occurs with the environment, light signals when the sleep cycle ends + vice versa.
Supporting evidence for the role of Extrogenus zietgibers and exogenus pacemakers
+Ralph et al found transporting the SCN (exogenus pacemaker) of abnormal hamsters with a 20 hour circadian rythm to normal hamsters resulted in the normal hamsters displaying the same abnormal patterns- suggests exogenus pacemakers (SCN) regulates sleep wake cycle
-Animal study, cant generalise
+Siffre- lived in a cave and had no acess to light, when he emerged his circadian rythm was abnormal at 27 hours suggesting exogenus zietgibers (light) help to regulate the sleep wake cycle
-Small sample, lacks generalisability
Aschoff and weber- exogenus zietgibers’
+Aschoff and Weber- studied participants in a bunker with no windows and only artificial light, participants had a longer sleep/wake cycle of 25-27 hours- suggests light is used to regulate a 24 hour sleep wake cycle.
Exogenus Zietgibers- cave and bunker study
Siffre- Cave case study
Aschoff and Weber- bunker study
What is the role of exogenus zietgibers?
(In the sleep wake cycle) they regulate the circadian rythm to 24 hours to match the environment by signaling when to inhibit the release of melatonin.
