Saturday, April 20, 2013

A hormone is a chemical manufactured by glandular tissue and circulated in the blood that has a regulatory effect on tissues or organs distant from it’s source.  For example, insulin is produced in the pancreas and released into the blood to facilitate the use of glucose in the cells of the body.  It thereby causes the lowering of blood sugar and the “burning” of glucose in the cells.  Epinephrine is produced in the adrenal gland on top of the kidney and has the effect of increasing central circulation,  making the heart pound and the breathing deepen, slowing digestion, widening the pupils and contracting skeletal muscle (the “fight or flight” response).

The chicken responds to lengthening or shortening of the photoperiod by increasing or decreasing the amount of the Gonadotropin Releasing Hormone which switches on or off the response of laying eggs.  Controlling the photoperiod with artificial lights keeps the GnRH in circulation so hens will continue to lay through the winter.

In short, we have many hundreds of hormones that control our physiologic processes.  I am not a chicken so perhaps the lengthening day in Spring won’t cause the GnRH to be released, but the lengthening day has an amazing effect on my energy, wakefulness, and willingness to be productively employed.  In midwinter, though the days are shorter, artificial light and heat make my garage a tolerable place to work, but time just slips away like sand through my fingers.  Yet, as the days lengthen into March and April, I have time and energy to get  those projects I neglected  all winter done and invent new ones.  This morning I got up, finished a novel, cut and hauled firewood for several hours, shoveled snow off of our construction project at the cabin, removed the holy tarp I had covering it and replace it with new, loaded up, drove home, and here I am writing this at almost midnight.  If it were December, I would have run out of juice hours ago.  Reduction of melatonin production due to the increasing photoperiod may be why energy levels peak as the days lengthen.  That tricky pineal gland makes all that melatonin all winter to help us hibernate, I guess.  Anyone for a pinealectomy?