Posted by Cam W. on February 13, 2001, at 13:50:56
In reply to Cam what is ..., posted by willow on February 13, 2001, at 12:17:40
Willow - Thanks for the welcome back. I'm glad to be back, I think.
Sure, give me the tough questions.
The hypothalamus is a brain structure under the thalamus and is kinda like the brain's "quarterback", in many ways. It contains hormones and other neurosecretions that control many metabolic activities (eg body's water balance, sugar & fat metabolism, body temperature regulation, etc). More importantly, for our discussion it "calls signals", ie pumps out inhibiting and releasing hormones.
Some example of these hormones are corticotropin-releasing hormone (CRH), follicle-stimulating hormone-releasing hormone (FSHRH), growth hormone-releasing hormone (GH-RH), antidiuretic hormone (ADH), luteinizing hormone-releasing hormone (LH-RH), etc. The hypothalamus basically integrates the sympathetic and parasympathetic nervous system activities.
These hormones stimulate the pituitary (the body's "running back" or "halfback") to release hormones which are sent to organs and structures in the body, including sexual organs and the adrenal glands (which produces and secrets a variety of substances, including cortisol which is involved in depression via the HPA axis), causing release of still more hormones and enzymes.
The pituitary (an endocrine gland), upon hormonal signaling by the hypothalamus, releases it's own hormones which influence growth, sexual development, thyroid function, and, as mentioned above, adrenocortical function. It does this by chemically signaling other endocrine glands (testes, ovaries, part of the pancreas, adrenal cortex and medulla, thyroid) to release various substances.
I hope that the above explanation shows the interaction of the endocrine system and stress (cortisol) systems. (it's been a long time since I tried to put many of the functions of these structures together, instead of focusing on individual actions).
Basically, I guess, the hypothalamus responds to bodily conditions (eg stresses - heat, cold, fear, anger, lust, etc) and then tells the pituitary to do something about it. The pituitary signals the appropriate bodily organs and systems and tells them to return to normal (called homeostasis). Disruption of this signaling leads to disorders like depression, diabetes, aberent sexual drives, hyper- or hypothyroidism, ad nauseum).
I do hope that I am making some sense here because I am doing this more or less off of the top of my head. Someone who is closer to school age, and has taken classes in this stuff more recently than I have can probably give a better explanation than I have (but I tried).
I hope this helps somewhat, Willow. I realize that what I am trying to say is not too clear.
Can anyone out there give a clearer explanation of what I am saying and fix any mistakes that I have made. It would be appreciated.
Thanks - Cam
poster:Cam W.
thread:53864
URL: http://www.dr-bob.org/babble/20010212/msgs/53889.html