Biological rhythms (ultradian rhythms)

Question 1

Sleep cycle occurs how every so often?

Answer 1

Sleep cycle occurs in 90 minute periods during your sleep
There are 5 different stages which are all measured by brain wave activity using a EEG

Question 2

Describe stages 1 and 2 of the sleep cycle

Answer 2

Light sleep
Easily woken up
Brainwaves become slower and more rhythmic
Slowing more when sleep becomes deeper

Question 3

Describe stages 3 and 4 of the sleep cycle

Answer 3

Difficult to rouse a person
Deep sleep
Delta waves which are slow and have a greater amplitude

Question 4

Describe stage 5 of the sleep cycle

Answer 4

REM (rapid eye movement)
Fast, jerky eye movement
Body paralysed but brain activity speeds up