00:00:00
It effects grown men, little boys and even happens to males still in utero.
00:00:04
You know, the ability to "pitch a tent" in the morning,
without any actual camping skills.
00:00:09
Now that we got the one obligatory joke out of the way, we can get to the hard facts
of nocturnal penile tumescence, otherwise known as "morning wood".
00:00:18
It turns out morning erections are part of the normal sleep cycle
and occur multiple throughout the night.
00:00:23
The mind and body go through stages of sleep, from non-REM stages, which gradually become deep sleep
finally followed by REM or "Rapid Eye Movement" sleep which is actually fairly shallow sleep.
00:00:33
This cycle occurs between 4 or 5 times a night.
00:00:36
As you enter REM sleep, not only do dreams occur, but a few physiological changes take place as well.
00:00:42
Namely, your brain begins to shut off some neurotransmitters in an effort to regulate your body,
and in some cases stop you from acting out your dreams.
00:00:49
One of these neurotranmitters, norepinephrine, happens to be involved with the control of erections.
00:00:54
Specifically it causes vasoconstriction of penis blood vessels, actively preventing an erection.
00:01:00
It is like a stop sign for blood flow. But as you enter REM sleep, norepinephrine decreases and testosterone related actions
are now able to take place.
00:01:08
This leads to vasodilation, or increased blood flow to the blood vessels, ultimately causing an erection.
00:01:14
Why is this important?
00:01:15
Well, similar to muscle and other tissue, at night this extra blood increases oxygenation,
serving as a system of repair and helping to maintain functionality.
00:01:23
But why do we often wake up to this pleasent surprise?
00:01:26
Well, we often wake up just out of REM sleep, and as a result
see the remnants of this sleep stage.
00:01:32
There is also evidence that a full bladder can contribute to morning wood.
00:01:35
The increased baldder size for the night stimulates a region of the spinal cord
which can cause a reflex erection.
00:01:41
The physiological benefit of this is to prevent you from urinating in your sleep.
00:01:45
But most men can attest to the difficulty proposed by this conundrum after waking in the morning.
00:01:52
Got a burning questions you want answered? Ask it in the comments or on facebook and twitter.
00:01:57
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