Talk:Human homeostasis

Purpose

This article may be an intro to all those Main articles that already exist on this topic. Mikael Häggström (talk) 19:32, 5 December 2007 (UTC)

Merge from Blood lipids

I started that article a long while ago, but the only function it has beyond all those that already exist is to show the dynamics of those lipids, and as such, it would fit better by expanding that section in this article (which is currently empty).Mikael Häggström (talk) 08:38, 17 August 2010 (UTC)

Actually, this article is very much an overview article and as such, it is really worthwile. Lova Falk talk 10:07, 10 October 2012 (UTC)

Merge with Homeostasis

I would like to make an urgent plea to redirect this article on “Human homeostasis” to the Homeostasis page.

There a several reasons. Firstly, most of the work on homeostasis relates to the mammalian homeostatic mechanisms, precisely because of their bearing on our own (human) physiology and disease. It is therefore almost impossible to support two separate articles, one on human homeostasis and a general article on ‘homeostasis” as the two will cover almost exactly the same physiology.

The second reason is that the mechanism whereby homeostasis comes about is finally mentioned, almost in passing, only in the very last sentence of this article. None of the rest of this article supports this final statement on the mechanisms responsible for homeostasis There is, for instance, the statement that the “the kidneys are responsible for regulating blood water levels…”. But perfectly healthy kidneys will excrete 20-30 liters of dilute urine per day, killing the person through dehydration, if the osmosensors in the hypothalamus, or their ability to communicate with the kidneys via the secretion of ADH into the blood (via the posterior pituitary gland) are compromised. Thus the kidneys have no “responsibilities” – they are passive organs that respond to signals, mostly in the form of hormones, that originate from tissues that contain sensors that detect errors in the osmolality and electrolyte concentrations in the blood plasma. It is the totality of these negative feedback systems, each component as important as the other, that regulates the internal environment, and maintains life. To single out the kidneys as “the regulators of blood water levels” is therefore highly misleading and inaccurate, making a travesty of the science of physiology.

Unfortunately all of the headings and subheadings in this article make the same mistake. Only the subsection on “Calcium” makes mention of a sensor which can detect errors – in this case, in the “blood calcium” - but without specifying that it is the plasma ionized component of the “blood calcium” concentration that is measured and is homeostatically controlled.

In short, this article is not about “Homeostasis”, and does no justice to the science of physiology or the topic of homeostasis. Cruithne9 (talk) 16:18, 19 June 2016 (UTC)

OK—no objection. Neither design is inherently wrong: either (1) two articles, homeostasis and human homeostasis, in the spirit of WP:Summary style and WP:Splitting, or (2) one article that covers all homeostasis, including the branching tree through life, plant, animal, mammalian, and human homeostasis, and continually keeping straight which level is being talked about (critical thinking). For example, we should not talk about an aspect of homeostasis as being human if it is clearly germane to all mammals. The latter reminds me of this. And Cruithne9 is quite right that the two-article design will inevitably contain a lot of overlap from animals generally to humans specifically. If you really think critically, the overlap is probably too much to truly warrant separate articles, although I don't say that as an absolute. Not saying separate articles can't be done. The question is, in the execution of either of those two designs, "Have we done it well enough yet?" Cruithne9 shows a good example of how, no, we haven't yet. The highest triage priority is getting someone knowledgeable and interested in the topic area to work on the articles and reach a better level of content/execution. If we have that, then we can leave the question of "which article design to follow" to their judgment. IMHO, I encourage Cruithne9 to work on them and see how things shape up. If it is desired to follow the one-article design from the get-go, one might run into the problem of the intermediate states being ugly and criticized by drive-by reversions. If so, one suggestion is to sandbox a new article all the way to the point of being decent and then overwrite the homeostasis article with that result and turn human homeostasis into a redirect, all at once. Quercus solaris (talk) 17:07, 19 June 2016 (UTC)

If there are no further comments or objections to the redirection of this article to the Homeostasis article, I will institute the redirect this weekend. Of course, it can always be reversed if there are major misgivings about this move. I think the Homeostasis article now contains everything that this article is expected to cover. Cruithne9 (talk) 16:46, 22 June 2016 (UTC)

There is info here that is not in Homeostasis yet. It should all be integrated there before the redirecting. In other words, I'm not against merging this one into that one, but the work of merging has to get done as part of that process. Quercus solaris (talk) 22:01, 23 June 2016 (UTC)

Hi Quercus solaris. Thank you for your comment above. I have had a look at this article (Human Homeostasis) again, and wonder what could be used in the general Homeostasis article. The headings which are present here but not in the Homeostasis article are: "Energy", "Iron", "Copper", "Zinc", "Fats", "Hemostasis" and "Sleep". What is written under each of these headings is extremely brief and hardly relevant to "homeostasis". This is because there is a general confusion between "metabolism" and "homeostasis". Metabolism is what happens to elements or compounds when they are absorbed, utilized, moved in and out of various body compartments and ultimately excreted. Homeostasis is about keeping the concentration of certain substances (or physical entities such as temperature or pressure) in a particular body compartment at a constant level. Thus, glucose "metabolism" covers the entire field from the composition of the food eaten, to how it is digested, absorbed from the gut, and then distributed around the body, and what it is turned into (i.e. the whole of intermediary metabolism), and ultimately in what form it leaves the body. "Glucose homeostasis", on the other hand, refers to the mechanisms whereby the blood glucose level is kept within very narrow bounds regardless of what is happening to "glucose metabolism" in general (i.e. whether large amounts of glucose are entering the body from the gut or not, or how fast it is being burnt in muscle during exercise etc., etc.). There is almost certainly "glucose homeostasis" inside cells, as glucose in high concentrations binds to proteins and denatures them, and, obviously, too little intracellular glucose means that cellular metabolism comes to a halt. So it certainly would make a great deal of teleological sense for there to be intracellular glucose homeostasis. But the mechanism whereby the intracellular glucose level is controlled (within very narrow concentration limits) is unknown, despite our very extensive knowledge about intracellular glucose metabolism. The same can be said about any of the other headings in this article - they merely touch on the fact that iron, copper, zinc etc., are metabolized by the body but make no mention of what aspect of their metabolism is homeostatically controlled - largely because that is not known. For instance, the first heading is on "Energy", which states that Energy intake = internal heat produced + external work + storage. This is simply a very elementary statement of "Energy Balance" or "Energy Metabolism", which does not imply "homeostasis". In fact, very few Nutritionists or Physiologists would say there is "Energy Homeostasis" in the sense that despite how much is eaten, the amount of energy that is stored is kept constant, by raising or lowering the metabolic rate in response to the size of the meal that has just been eaten or even the longer-term average intake of food. In fact, physiologists and nutritionists would emphasize the exact opposite: any food energy not used for heat production and exercise is stored as fat; and because heat production and exercise very often do not balance intake, an obesity epidemic has arisen across the globe. In any case, where are the sensors which detect excessive food storage? and where are the effectors that deal with the errors that the sensors detect? The energy balance equation in the article does not imply "homeostasis". The water level at any point along a natural river can be stated in the same general "balance formula" of water in = water out + what is stored in the that stretch of river. There is no homeostasis or water level regulation in a system such as this. Thus, simply because Energy intake = internal heat produced + external work + storage is a truism, does in no way suggest homeostasis.

I have extracted from this article what can uncontentiously be regarded as "homeostasis', and how that homeostasis comes about. To venture into all sorts of speculation about "Sleep homeostats" etc., is not encyclopedic information, but should be left to the Sleep physiologists to discuss in the relevant scientific journals. If, however, anyone would like to suggest a homeostatic topic to be included in the main Homeostasis article, I will certainly put my mind to it. Cruithne9 (talk) 08:33, 24 June 2016 (UTC)

Hi. Thanks for the effort and follow-up. Sounds like you have analyzed it well, point by point. This takes care of my concerns, other than that the history section should be moved over rather than lost. Unless you feel it is not good enough to keep. I'll accept your judgment on that. Thanks again, Quercus solaris (talk) 03:16, 27 June 2016 (UTC)

Thank you Quercus solaris. I will move the history section across later today; and will then, after a day or two redirect this article to the main Homeostasis article, which needs some finishing touches. Cruithne9 (talk) 05:49, 27 June 2016 (UTC)