The Functions of Sleep

If you've read my last post about sleep (how much sleep do we need), then you'll have noticed that I didn't explain about the functions of sleep. So, I've decided to talk (or should I say write) about them now.

Sleep is still not fully understood, and so the understanding of its functions is also not fully known. However we do have a pretty good idea about some of the proposed functions of sleep.  

1. Restoration 

It has been shown that sleep deprivation has an (assumed) affect on the immune system and can impair its function ( study by Zager et al. in 2007).

Wound healing has also been closely associated with sleeping, and deprivation of it can be a hindrance to the healing of wounds (study conducted by Gumustekin et al 2004).

Sleep has not been directly linked to body growth, however a study has shown that 8 hours of sleep (more specifically slow-wave-sleep), did have an effect on the growth hormone levels of men. (Study by Van Cauter, Leproult, and Plat).

On the other hand a study done on 305 children over a period of 9 years (1-10), tried to establish if height and weight correlated with sleep. The results received suggested that sleep had no effect on a child's growth. (Study by Jenni et al. 2007).

2. Ontogenesis 

The activity occurring during newborn REM sleep appears to be particularly important for development (according to the hypothesis of ontogenetic REM sleep).

Sleep deprivation at an early age has been linked to behavioural problems in later life, decreased brain mass, an abnormal amount of neuronal cell depletion, and permanent sleep disruption.

From various studies on REM sleep, it appears that it is important for brain development.

3. Memory Processing 

Working memory has been shown to be affected by sleep deprivation.

Important for support of higher levels of cognitive functions such as reasoning, episodic memory, and decision making, working memory is also important for further processing information.

Studies have been done on this, and the results point to the conclusion that sleep deprivation means a reduced working memory.

It's not so easy to concentrate either when feeling sleep depraved.

Short Summary

All-in-all, I think we can all agree that sleep is important and that our bodies do need it, otherwise why have it.

I'm sure I've missed something out, if you notice that something is missing, feel free to make a comment.