Been reading about biological rhythms for less than a minute and I’m already confused…

These are rhythms lasting ‘about one day’. The best example of a circadian rhythm is the sleep-wake cycle, associated with which are many cyclical changes with active and dormant periods, for example body temperature and urine production. These rhythms allow animals to prepare for predictable daily environmental changes, such as night and day.
Research has involved participants being deprived of possible zeitgebers (‘time-givers’) like sunrise and sunset, temperature changes during a 24 hour period and wristwatches! Participants tend to maintain a cyclical rhythm but it extends to about 25 hours (Siffre, 1975).
So, endogenous pacemakers can keep a rhythm but exogenous zeitgebers are needed to stick to a 24 hour rhythm.
Where is the brain’s internal clock?
The suprachiasmatic nucleus (SCN) in the hypothalamus is a bundle of nerves with an inbuilt circadian rhythm. This is a particularly important endogenous pacemaker. Evidence for this comes from studies in which the SCN has been cut in hamsters to result in disrupted circadian rhythms (Menaker et al., 1978).
What keeps the brain to a 24 hour rhythm?
Without light the brain’s day would be 25 hours long (a free-running clock). Light is a very important zeitgeber - flashes of light are enough to ‘reset’ the internal clocks of animals living in the dark (Aschoff, 1979). One blind man needed to take stimulant and tranquilizing drugs to maintain a 24 hour cycle!
How does light ensure mammals maintain a 24 hour rhythm?
The pineal gland in the brain converts the neurotransmitter serotonin into the hormone melatonin.
Melatonin is released into the blood stream and causes rhythmic changes around the body. Although the need for sleep is not affected by light, melatonin plays a role in the coordination of the sleep-wake cycle.
(Words are too big and confusing - I hope this doesn’t come up on a test.)

or so it seems,
One life for yourself and one for your dreams.
You drift through the years and life seems tame,
Till one dream appears and love is its name.
And love is a stranger who’ll beckon you on,
Don’t think of the danger or the stranger is gone.
This dream is for you, so pay the price.
Make one dream come true, you only live twice.
And love is a stranger who’ll beckon you on,
Don’t think of the danger or the stranger is gone.
________________________
No ones ever lived with eyes on the back of their head, but our everything we see starts somewhere deep in between. Gonna try hard to stop looking at things so much, it makes everything harder to forget.
“My cocaine soundtrack was The Cure. I loved all their music, but I listened to this one song on repeat while I did bags and bags of cocaine,” she remembers. “Whatever I do, it’s not enough. Isn’t that funny? I didn’t think there was anything wrong with me until my friends came over and said, ‘Are you doing this alone?’ ‘Um, yes. Me and my mirror’.” She credits her dad with saving her, who put it rather well when he said: “You’re f***ing up, kid.” - if i respect her for that, am i a hypocrite for thinking shes a total douchebag?
On another note, isn’t it strange how there’s a Sunday but not a Starday? Especially when the Cherubim are supposed to be the guardians of the stars. It’s not a popularity contest. We all like the stars better anyway.
I’ve decided the bands gonna be called Zoetic… or something of that nature. Amazing take on a beautiful song:
Dance you fucker, dance you fucker, dance.
Am I going home tomorrow? I have no idea if my mother’s cancer has been removed or disposed of or whatever you want to call it. I’m missing prelim exams right now and kinda stressing out… My dads being a dick for some reason and apparently the doctors were mumbling when she asked for her results. Theyre gone to the hospital now. I feel indecisive.
Crystallized prize and conceded eyes
She waits for me, reluctant but steady
Dragging in every subtle goodbye
Her lips refuse to let me go.
When you think about it, Hitler was the first real pop star.” - David Bowie