Pineal GlandRipple

Ireland

Where is it located? Between two hemispheres of brain Tucked into groove where two rounded thalamic bodies join Dorsal aspects of brain’s diencephalon region Part of both nervous system and endocrine system

What hormones does it produce? Melatonin

derived from tryptophan, regulates circadian rhythm (sleep cycle) and body temperature

What effect does the hormone have? Regulation of sleep patterns and seasonal functions (i.e.

hibernation) Influences sexual development, hibernation, and seasonal

breeding Helps protect body from cell damage caused by free radicals Jet lag

Why is this hormone important to homeostasis? Homeostatic sleep schedule thermoregulation

Feedback Mechanisms and Antagonistic Hormones Source of circadian rhythms (sleep patterns) lies in

suprachiasmatic nuclei (SCNs) Day: SCN decreases melatonin production Night: SCN increases melatonin production

What releases/inhibits melatonin production? Inhibited when retina detects light Stimulated when in darkness

What happens if the gland does not function properly?

Too much Drowsiness/insomnia Reduced core body temperature

Not enough/not at all Seasonal Affective Disorder (SAD) – depression in winter More inflammation Weakened immune system Increased risk of cancer

What can be done? Supplements are available Doses of melatonin can be used to treat depression,

insomnia, and jet lag.

Sources http://en.wikipedia.org/wiki/Pineal_gland http://www.crystalinks.com/thirdeyepineal.html