Biological Approch: Circadian Rhythm

Question 1

What are the four biological approaches to sleep and dreams

Answer 1

Circadian Rhythms
Evolutionary Theory
Restoration Theory
Activation Synthesis Theory

Question 2

Circadian Rhythms

Answer 2

Is the 24 hours sleep/wake cycle which controls period of activity and inactivity and is tied to sunlight and body temperature. Individuals body temperatures are lowest at 3-5am.

Question 3

Light in relation to circadian rhythms

Answer 3

Perception of light is taken in through the retina then travels down the retinohypothalamic tract to the SCN in the hypothalamus which tells the pineal gland to produce melatonin.
When sunlight patterns are interrupted the 24 hour cycle changes to a 25 hour cycle as found by Michel Siffre because the light cues that lead to melatonin production are disrupted.

Question 4

Adenosine

Answer 4

During the day adenosine builds up which causes feelings of fatigue which induces a regular sleep-wake cycle. Adenosine then decreases during sleep.

Question 5

What part of the brain controls circadian rhythms

Answer 5

Superachiasmatic nucleus (SCN)

Question 6

Who may experience problems with their sleep wake cycle

Answer 6

Visually impaired, shift workers and people who travel frequently.

Question 7

What is homeostasis

Answer 7

Generated pressure for sleep and waking - longer you are awake stronger the desire to sleep and vice versa.

Question 8

What is the endogenous pacemaker

Answer 8

Internal clock

Question 9

What is the exogenous zeitgebers

Answer 9

External time givers that help regulate body clock (sunlight, food)