4.2.2 - Biological Rhythms

Question 1

What are biological rhythms

Answer 1

They exert an important influence on he ways in which the body system behaves

Question 2

What are the 2 shoes of biological rhythms

Answer 2

• endogenous pacemakers: the bodies internal clock that regulates many biological rhythms
• exogenous zeitgebers: sternal queues which may affect our biological rhythms. For example, daylight affect the sleep cycle.

Question 3

What is a circadian rhythm?

Answer 3

24 hour cycles
E.g. The sleep, wake cycle and core body temperature.

Question 4

How is the sleep wake cycle affected by biological rhythms

Answer 4

• light and darkness actors in exogenous zeitgeber. The effect of daylight is seen in humans, feeling drowsy at night and alert during the day.
• sleep wake cycle, rhythm dips at points in the day strongest sleep drive is 2 to 4 am and one to 3 pm
• However, if we have sufficient sleep, the dips are less intense

Question 5

Explain the work of Siffre

Answer 5

• he locked himself in a cave without natural sunlight
  · In all of siffre’s studies his free running biological rhythms settled to 25 hours. However this did alter as he aged with the occasional 48 hour cycle recorded
• the only thing influencing siffre underground was his internal body clock
• Siffre left the care in mid-September 1962 but thought it was mid august
  -this suggests the human body clock relies an exogenous zeitgebers to help it to keep time
• without exogenous factors like light our body clock can extend, making us believe a day is longer than it is.