Lesson 1
Cells in a tiny pine cone
Pinealocytes (say PIN-ee-al-oh-sites) live in the pineal gland. It is a tiny gland deep in the middle of your brain.
The pineal gland got its name because it is shaped a bit like a little pine cone. It is only about as big as a grain of rice.
Pinealocytes are small, round cells with a few short arms. Lots of tiny blood tubes run between them.
Wow!Your pineal gland is tiny, but it gets a lot of blood flowing through it, so its hormone can travel around your body quickly.
Lesson 2
Telling your body it's night
Pinealocytes make a hormone called melatonin (say mel-uh-TOE-nin). They make lots of it at night, when it is dark, and very little in the daytime.
Your eyes tell your brain when it is light. That news gets passed along to the pineal gland, and the pinealocytes slow down.
Melatonin helps your body know that it is night and time to get sleepy. This helps keep your body clock on track.
Try thisScroll up to the 3D model and press Turn off the lights. At home, try keeping lights dim and screens off before bed, so your pinealocytes can do their job.