Infradian And Ultradian Rhythms

Question 1

Ultradian rhythm

Answer 1

• Takes less than 24 hours
• e.g sleep cycle

Question 2

Infradian rhythm

Answer 2

• Takes longer than 24 hours
• e.g menstrual cycle

Question 3

Menstrual cycle

Answer 3

• The female menstrual cycle is an example of an infradian rhythm
• It is governed by monthly changes in hormone levels with regulate ovulation
• The cycle refers to the time between the first day of a women’s period, when the womb lining is shed, to the day before her next period

Question 4

The 4 stages of sleep

Answer 4

Stages 1 and 2:
- A light sleep, where the person can be easily woken
- Brainwave activity begins to become slower

Stages 3 and 4:
- This is deep sleep, and it is difficult to wake someone at this stage
- Brain waves are even slower

Stage 5 (REM sleep):
- The body is paralysed yet brain activity speeds up significantly, in a manner that resembles the awake brain
- REM stands for rapid eye movement to denote fast, jerky activity of the eyes under the eyelids
- This stage is highly correlated with the experience of dreaming