Bones

[Guest CHINCHILLA]

I was watchin a documentry on discovery once about bones. (like 6 years ago) and they were talkin about repairing broken bones with cells that deploy acid mealting a layer of bone and calcium things folowing them deploying calcium. i just need to know the name of the cells....anyone know???

[greg1917]

Clarity helpful would be, possibly that repeat if could you.

 

No seriously, could you be a bit more specific? It sounds intersting.

[Guest CHINCHILLA]

Its a 1 cell organism (i think) that releases acid onto the bone. Mealting a layer of the bone. Thier acid is strong enogh to melt through sheet metal. Then behind them comes along a couple of calcium depositers the release calcium to fill in the burned spot. (bone reperduction)

[Guest CHINCHILLA]

Just to let you know im 13 so some stuff might be rong but im 99% sure its rite

[Glider]

The cells you're thinking of are Osteoclasts and Osteoblasts. When a bone is broken, the first thing that happens is the periosteum (the skin covering bone) and surrounding tissue bleeds. There is also a large, localized inflammatory response where histamine and other substances cause the capilaries to dilate, allowing more blood to the region (bone healing is an inflammatory process). Osteoclasts begin to clean up the broken edges and disolve any small fragments. White cells pervade the area dealing with any potential infection.

 

When the blood clots around the break, osteoblasts begin to lay down a calcium matrix within the clot, forming a callus (on an x-ray, it looks like a swollen lump of bone). Other cells begin to lay down collagen within the matrix to form proper bone. When the break has healed, leaving a swollen lump of bone where the break used to be, the osteoclasts come along and disolve the excess, 'shaving' the bone back to shape. In young people, after a year or so you can't tell where the break used to be. On older people, there's just a slight swelling where it used to be.

[Skye]

Just as an aside, since the imflammatory response is important in both controlling infection and aiding repair, why are anti-imflammatory drugs so frequently prescribed?

[Radical Edward]

I would suspect that the inflammatory response isn't that useful in the repair process itself, it just provides a good cushion to the region being repaired (for example a sprained ankle). while useful in the wild, the response is no longer required, as sitting around and having food bought to you is a realistic possibility these days. Similar for scarring too, where the scabbing is just there to stop infection getting in, but makes the scar look worse. I recall an experiment where if you stop the nasty scab forming (the wound was sealed using something else like surgical glue I think), then the wound is quicker and more neatly healing, but more prone to infection (which can be dealt with now)....

 

this is old second hand knowledge btw. I could be wrong.

[Glider]

The anti inflammatory drugs are prescribed generally for pain control; they help control the aspects of inflammation that results in pain such as the effects of histamine and prostoglandin release, both of which cause pain (particularly prostoglandins and substance P). However, these drugs don't have a significant impact on the inflammation itself. Whilst they might reduce it a little, and make it more bearable, they won't stop it. The inflammatory process is absolutely necessary in bone healing. Unlike muscle and skin tissue, bone cannot repair itself. It is entirely dependent on other cells transported to the area and delivered in high concentrations through the inflammatory process. Localised histamine release causes the capillaries in that area to dilate so they become 'leaky' and blood, white cells and other useful things can get to the area. The side effect of this is pain and this is mostly what anti inflammatory drugs help control. If you were to eliminate the inflammation caused by a broken bone, you would stop the healing process.

 

It's true about the use of glue though. The plastics will often use cyanoacrylate (superglue) to hold together lesions where suturing is a real problem or would result in scarring (so it's used often on children, and usually for facial injuries, particularly in fine skin like eyelids). The use of this stuff is excellent for reducing scarring, but they only use it where the wound would heal through primary intent (two edges healing together). Where the would needs to heal through secondary intent (a deep wound has to granulate up from the bottom), sealing the edges together risks forming an abscess which could not drain, which would be worse.

[Radical Edward]

what about the inflammation due to a sprained ankle, or knock then? Is it the body just inflamin just in case there is bone damage? and as for infections, is it just that leakiness providing better access for all the antibodies and so on?

 

thanks by the way

[Glider]

Any tissue damage will result in a degree of inflammation. Damaged cells release prostoglandins and cause the release of histamine, which results in inflammation. As you quite rightly surmise, the capillary leakiness caused by the inflammation does provide better access for antibodies and so-on. The thing to remember is that living tissue can repair itself. Bone however, is not living tissue and cannot heal itself. It must be healed, and this is more dependent on the inflammatory process than the healing of a sprained ankle. A subtle difference I grant you, but a difference nonetheless.

 

Inflammation serves several purposes; it hurts, telling you to keep off it, and to look after it whilst it heals. It provides infection control, and it provides the materials needed for the tissue or bone to heal. The swelling caused by a knock is more likely to be a bruise (haematoma). Whilst this does involve a degree of inflammation, the pain of a bruise is more due to the pressure the interstitial bleed exerts on surrounding tissues. Nonetheless, inflammation will occur here too, as interstitial pools of 'dead' blood are prime sites for infection (really nasty deep abscesses), so the pooled blood needs to be broken down and removed asap.

 

On the "Eeeeww" side things, bad haematoma often exert a lot of pressure on the surrounding tissue, and this can lead to localised necrosis. In these cases, leeches are often used to alleviate the swelling. Another yukky is that they are now using fly larvae (maggots) to clear up sloughy or necrotic open wounds too. These are extremely effective. They begin by applying very tiny, young maggots to the site, cover with a dressing and leave it alone. After a while (10 to 14 days), they uncover the site revealing a bunch of very large, well fed larvae (some of which will have already pupated) and a nice, clean healthily granulating wound. It's bloody marvellous to see! Significantly reduces scarring too, and the maggots keep the site aseptic as they excrete amonia. Brilliant!

 

De nada

[Radical Edward]

"nice" thank goodness I ate my breakfast a while ago. Are leeches and maggots quite regularly used now then? I had heard of sugestions of them being used a few years ago, but nothing really since then.

 

incidentally, what do you mean by granulating?

[Glider]

You probably won't see them sold over the counter is Boots, but their use is not uncommon now. Plastics use leeches, as it's the best way to reduce bad swelling on skin grafts without scarring. Leeches release anticoagulants too, which helps to keep the blood flowing through new grafts.

 

Granulation is the process by which deep wounds (i.e. deeper than skin) heal. In deep, open wounds, connective tissue stroma (from which connective and scar tissue is generated by the rapid division of fibroblasts) and perenchymal cells (which form the differentiated cells of an organ, again by division) are involved in repair. Fibroblasts divide rapidly and the manufacture of collagen helps provide strength and support to the area. At the same time, small blood vessels increase in number through increased cell division, and together, these processes create an actively growing, connective tissue mass which is called granulation tissue. This forms a framework across the wound, or in very deep wounds, begins at the bottom and works its way up (known as healing by secondary intention), across which epithelial cells migrate to form new skin, closing the surface wound (known as healing by primary intention).

 

If you look into a deep lesion or a healing ulcer, you'll see that the bottom of it looks like bright pink, homogeneous, wet, healthy looking skin. That's granulation tissue (any other colour e.g. livid red, green, yellow or black is less good, and you should probably tell somebody). A smart thing about granulation tissue, is that it secretes its own antibiotic fluid too.

[Skye]

I did a weeks work experience for school when I was 16 at a local vet clinic. A dog that had been fixed up after being hit by a car (it had had a leg lacerated and broken) was getting a check up when the vet said "Oooh look he has some friends", and out dropped about a dozen maggots.

 

Can stitching up a wound cause similar problems to gluing it, especially without internal stitches to prevent a fluid filled space forming?

[Glider]

Hehehe...as long as they're the right kind of maggot. The good kind will only touch sloughy or necrotic material. Others will eat you alive, like the kind that infest fly-struck sheep.

 

Yes. Stitching a deep wound can lead to an abscess. Any time the skin is allowed to heal over a cavity (and skin heals faster than underlying tissue), there will be a risk. It is done, but it is a judgement call depending on the depth and state of the wound. Where it is done, the cavity will have been well irrigated and cleaned out and topical intibiotics applied. The patient will also be on a short-course (5-7 days) of broad spectrum antibiotics, but there's always a risk. Minor infection can drain through sutures though, at least until the skin heals, but it can't where the skin is glued. I have seen cases where sutures had to be removed and the wound re-opened to remove necrotic material (a process called debriding) and then re-stitched.

 

Where the risk of abscessing is considered too great (e.g. the wound forms a deep cavity or a sinus under the tissue) or (more often) where there is nothing to stitch due to tissue loss, it won't be stitched, it will be packed to keep it open and a dressing applied on top. There are a variety of things which are made for this purpose, some of which (for really deep cavities) are liquids that are mixed with catalyst and poured into the cavity. The liquid then expands and sets to form a kind of foam-rubber plug. At weekly intervals the packing is removed, the wound is checked for infection, and re-packed. This allows the wound to granulate up from the bottom. When the wound is shallow enough, the packing is removed and the wound is dressed with a surface dressing only and allowed to heal over.

 

I think vets are underrated personally. What did you think of the vetinary work experience? Is vetinary work something you'd like to do?

[Skye]

I think vets are underrated personally. What did you think of the vetinary work experience? Is vetinary work something you'd like to do?

The vet thought he was underrated too when he performed a facelift on a Cocker Spaniel (their eyelids often fold over their eyes as they age and cause eye infections) for a tenth of the price a plastic surgeon would charge. Vets have to have a broad range of skills, even in a small clinic they perform all manner of procedures, on a variety of different animals. That being said from the little I've seen it's mainly desexing and terminating.

 

I wanted to be a vet at that stage, though that wasn't a great introduction, and probably turned me off it. Not that it was too gross; just mind numbingly repetitive...desex/put down/desex/put down... I have been out of school though a few years now, having loved and lost a few career paths. Being a little over a year through a BSc, I am thinking of a research career in some area of biology.

 

I don't like being stitched up, it always seems to hurt more than the actual injury. I had a cut once on the underside of my heel, perhaps 8mm deep by 30mm long, that healed fine without stitches, actually without any medical attention at all. For fairly minor cuts to epithelial or muscle tissue are stitches all that usefull?

 

Thinking about wounds, leech and maggot treatments, and vet science, made me remember how little treatment the cattle dogs would get (which involved being sprayed with whatever poisons the cows were). They would often get some decent cuts from the barbed wire, I saw them up to 6 inches long. Despite the rest of the dog being covered in mud their wounds were always perfectly clean and a nice healthy pink. Maybe we should just go home and lick our wounds, or at least have them licked for us.

[Glider]

Originally posted by Skye

The vet thought he was underrated too when he performed a facelift on a Cocker Spaniel (their eyelids often fold over their eyes as they age and cause eye infections) for a tenth of the price a plastic surgeon would charge. Vets have to have a broad range of skills, even in a small clinic they perform all manner of procedures, on a variety of different animals. That being said from the little I've seen it's mainly desexing and terminating.

Well...it goes to show the power of human vanity I guess. On the other hand, with hair covered skin, I suppose the vet is less pressured to avoid scarring. Nonetheless, they do some amazing procedures. I knew one who performed a rhinoplasty on a bulldog with breathing problems (stupid to breed a dog that can't breathe in the first place). I do know that student vets have to have a greater level of qualification to enter vet school than medical students do to enter med. school. Not surprising really. They deal with so many different species, most of which have different physiologies and none of which can tell you where it hurts. I guess it could get a bit repetitive in a small animal practice though (same as anything really), although I bet there must be hugequeues for positions as zoo vets.

 

I wanted to be a vet at that stage, though that wasn't a great introduction, and probably turned me off it. Not that it was too gross; just mind numbingly repetitive...desex/put down/desex/put down... I have been out of school though a few years now, having loved and lost a few career paths. Being a little over a year through a BSc, I am thinking of a research career in some area of biology.

I know what you mean there. I wandered around through a number of different jobs (the number was 6 if I remember rightly) and came to higher education later (some would say 'slow starter'...I prefer 'late bloomer'). Biology has always been one of my interests though. What particular area are you doing your BSc in?

 

I don't like being stitched up, it always seems to hurt more than the actual injury. I had a cut once on the underside of my heel, perhaps 8mm deep by 30mm long, that healed fine without stitches, actually without any medical attention at all. For fairly minor cuts to epithelial or muscle tissue are stitches all that usefull?

Not really. For minor cuts, if anything, stitches just increase the risk of infection. Stitches are only really used where the wound won't heal properly without them, i.e. if the edges are layed open and need tension to hold them together. If cuts like that are allowed to heal by secondary intention, they can leave large scars which most people don't like, especially in visible places (i.e. face, arms, legs etc.) and these can be avoided or at least reduced by suturing. Often you can get away using steristrips (thin strips of very sticky, tough material that can be laid over the cut holding the edges together). If there is a lot of tension (e.g. like a nephrectomy site on a 'big boned' person) they'll often use steel staples to hold it together. You're right about the stitches hurting more. This is true, but strange. If you think about it, the wound being stitched comprises a greater degree of trauma than the stitches do. Moreover, they'll usually administer lignocaine into the edges of the wound before stitching. Nonetheless, it still hurts. I think it's due to the expectancies of the patient. e.g. when you cut your heel, you didn't expect it...it just happened, so you had shock and surprise, and obviously some pain, but you didn't know it was going to happen. On the other hand, sitting in an A&E cubicle watching someone come at you with a needle, knowing they're about to stick it into you several times... That, I suspect, is what makes the difference.

 

Thinking about wounds, leech and maggot treatments, and vet science, made me remember how little treatment the cattle dogs would get (which involved being sprayed with whatever poisons the cows were). They would often get some decent cuts from the barbed wire, I saw them up to 6 inches long. Despite the rest of the dog being covered in mud their wounds were always perfectly clean and a nice healthy pink. Maybe we should just go home and lick our wounds, or at least have them licked for us.

Licking our own wounds might not be a bad idea. You really wouldn't want to have anyone else do it for you though...human mouths are really disgusting. Ask any A&E medic which is the worst to treat; an animal bite or a human bite. Human are almost guaranteed to fester...they are really horrible to treat. So you wouldn't want anyone else's saliva in your wound (dang!...and I was just gonna have breakfast too...)

 

Animals heal really well. My cat got hit by a car 9 weeks ago (multiple pelvic fractures) probably due to his apparent inability to tell the difference between a mouse and a mondeo. At the site of impact and the side where he hit the ground, there was bad bruising which you couldn't see. After a week however, all the hair fell out of those areas reavealing discoloured regions of skin. These then broke down into large open ulcers (really large relative to a cat). Nonetheless, with his constant licking, they always stayed pink and healthy (they're a lot smaller now, and should heal completely in about another 2 weeks I'd say). Humans, on the other hand, heal less well from injuries of the same severity (we are such a bunch of wimps in comparison).

[Skye]

I do know that student vets have to have a greater level of qualification to enter vet school than medical students do to enter med. school. Not surprising really. They deal with so many different species, most of which have different physiologies and none of which can tell you where it hurts. I guess it could get a bit repetitive in a small animal practice though (same as anything really), although I bet there must be hugequeues for positions as zoo vets.

It's kind of a shame we don't have any vet science students on this forum, they'd love this. They are probably all studying feverishly in the hope of becoming a zoo vet.

What particular area are you doing your BSc in?

Biochemistry. I've taken a very wide variety of subjects though so far (I can use surveying equipment for example) and I change my mind about every second week as to an area of specialisation. I was thinking biochemistry/neuroscience double major a little while ago. Then I emailed a researcher about group behaviour and he mentioned complex systems, which really are interesting. So I think I'll just have to see what happens, get some work in the labs and find out where the serious money is

I think it's due to the expectancies of the patient. e.g. when you cut your heel, you didn't expect it...it just happened, so you had shock and surprise, and obviously some pain, but you didn't know it was going to happen. On the other hand, sitting in an A&E cubicle watching someone come at you with a needle, knowing they're about to stick it into you several times... That, I suspect, is what makes the difference.

That's very true. In the case where I cut my foot I didn't realise untill I had walked back to the campsite (it was in a large cave under a waterfall, very nice) and saw a little trail of blood behind me.

Licking our own wounds might not be a bad idea. You really wouldn't want to have anyone else do it for you though...human mouths are really disgusting. Ask any A&E medic which is the worst to treat; an animal bite or a human bite. Human are almost guaranteed to fester...they are really horrible to treat. So you wouldn't want anyone else's saliva in your wound (dang!...and I was just gonna have breakfast too...)

I didn't so much mean other people as other animals. Though I can't see it as a treatment that would take off, perhaps because dogs aren't as clean as maggots or leeches. Not a great thought.

Animals heal really well. My cat got hit by a car 9 weeks ago (multiple pelvic fractures) probably due to his apparent inability to tell the difference between a mouse and a mondeo. At the site of impact and the side where he hit the ground, there was bad bruising which you couldn't see. After a week however, all the hair fell out of those areas reavealing discoloured regions of skin. These then broke down into large open ulcers (really large relative to a cat). Nonetheless, with his constant licking, they always stayed pink and healthy (they're a lot smaller now, and should heal completely in about another 2 weeks I'd say). Humans, on the other hand, heal less well from injuries of the same severity (we are such a bunch of wimps in comparison).

How much of this is purely psychological? Are we simply wimps or are there physiological reasons for it?

 

There are definately psychological reasons for it though, how can we better help people feel well (given that nurses skirts can only be so short)?

[Glider]

Originally posted by Skye

It's kind of a shame we don't have any vet science students on this forum, they'd love this. They are probably all studying feverishly in the hope of becoming a zoo vet.

If they have any sense, yes...but then, they are students . I see no reason to expect them to be any different from the rest of us, just 'cause they're smarter....er...:uhh:.

 

Biochemistry. I've taken a very wide variety of subjects though so far (I can use surveying equipment for example) and I change my mind about every second week as to an area of specialisation. I was thinking biochemistry/neuroscience double major a little while ago. Then I emailed a researcher about group behaviour and he mentioned complex systems, which really are interesting. So I think I'll just have to see what happens, get some work in the labs and find out where the serious money is

Hmmm...I only took one module in biochemistry (it was a prerequisite for neurosciences modules)...tricky subject! I can't remember there being much by the way of surveying equipment involved though. I might have been asleep of course. Neuroscience is a fascinating area though...I enjoyed that. What are these complex systems? They sound...er..complex. Is it anything like group dynamics?...not that I know much about that either mind you.

 

I didn't so much mean other people as other animals. Though I can't see it as a treatment that would take off, perhaps because dogs aren't as clean as maggots or leeches. Not a great thought.

Yeah...I can see a PR problem there too...though they did manage to sell the idea of maggots and leeches....weird.

 

How much of this is purely psychological? Are we simply wimps or are there physiological reasons for it?

There are definitely psychological factors involved, both behavioural and psychophysiological. One of the principle factors is our ability to see into the future (i.e. predict the probable outcomes of our behaviours). For example, one of the quickest ways to alleviate the pain of a hip replacement is to mobilise...just get up and walk around. The swelling goes down and the pain goes away really quickly. But many people won't. This is mainly through fear of pain...their hip hurts, and they think walking will hurt more, so they avoid it. Animals don't look ahead. My cat (for example) doesn't attempt to predict which behaviours will lead to pain. He gets up and walks. If it hurts him, he slows down or adopts an antalgic gait to compensate. But in getting up and walking, he's actually dealing with the cause of the pain...he's regaining the tone in his muscles, which will help support his pelvis, he's working the tendons which will ease the stiffness in his tendon sheaths and also reduce the inflammation. Animals allow actual pain to dictate the degree to which they behave. Humans allow the fear of pain to prevent them from behaving. As a result, things take longer to heal, e.g. bones mend faster if there is a little movement at the break, and grow stronger if they are made to bear a little weight whilst healing. Muscle and other soft tissue also heals faster if it is worked (within reasonable bounds). People who completely immobilise after an injury take significantly longer to heal than those who get up and about...and their prognoses are also less favourable, i.e. they are significantly less likely to regain full function of whatever was injured.

 

There are definately psychological reasons for it though, how can we better help people feel well (given that nurses skirts can only be so short)?

I think we could begin by reinstating a sense of personal control in the patient. The first thing that happens to people when they are admitted to hospital, is that all control is removed from them. People who, up until admission, were independant individuals are now told when to eat, bathe, go to bed, wake up and what is going to happen to them (which is also outside of their control). Even the language used by clinical staff facilitates this. An adult who might be something like an airline pilot, responsible for hundred of lives is told to "...just pop into bed and lift your shirt so we can look at your tummy". Once people lose their sense of personal control, they adopt a sumissive, passive role, sometimes know as 'the patient role'. They adopt attitudes and behaviours consonant with their perception of 'a patient'. Concommitant to the role of a patient is pain and suffering, and so the patient often begins to adopt 'illness behaviours', or 'pain behaviours'. These are reinforced in so many ways, by the patient, the staff and the relatives that I won't bore you with them here. Suffice to say, much of what a patient goes through is simply down to this loss of control and the resultant helplessness/anxiety associated with the 'patient role'. However, this is not to say that any pain or suffering involved is not real. It is. To be admitted in the first place, they must be ill/injured, but like when you cut your foot, you were'nt thinking about it and it didn't really hurt you that much (or at least, that's the impression I got), as you were in control, and there were other things going on (e.g. a really nice campsite under a waterfall...although in front or behind it would have seemed a wiser choice). But if you were in a position where you felt no personal control, you were forced into a patient role and its associated state of helplessness and anxiety, and people were paying attention to you and/or doing things to you because of the cut on your foot and so-on and so-on, then that injury would have taken a predominant role in your life. In effect, it would have become one of the most significant things in your life at that time, and so would any pain or suffering resulting from it.

 

The shortness of the nurses dresses do have an effect, but only in slightly under 50% of the patient population...and not usually the effect wished for...and certainly not by the nurses.

 

I just spent the last 5 years working alongside nurses (until 2001)...mad as badgers, the lot of them. But I have to say, in my opinion, of all the sterotypically 'heroic' professionals, soldiers, firefighters, surgeons etc., nurses are true heroes.:worship: :worship: :worship:

[Skye]

What are these complex systems? They sound...er..complex. Is it anything like group dynamics?...not that I know much about that either mind you.

It's a system of relatively simple things that interact to form a complex pattern. Weather, traffic flow, the CNS and ecosystems are examples. One of the principle ideas is that organisation can emerge from chaos simply by random and unorganised interactions. Another is that the sum of a system is, in a way, greater than the whole. Group dynamics are definately included, I'm reading a book on social insects. They are surprisingly complicated little critters. I covered a hole with soil and watched for a while, the ants returning to the nest just ran around like idiots on speed. I emailed a researcher from my school who said:

 

"if you kept watching you would have found that after awhile a number of ants would have started to dig into the soil. Some holes would be more attractive than others, through chance alone, so the ants would begin to concentrate their work efforts on only a subset of the original number of wholes. These successful holes would continue to attract more ants via a

process of positive feedback and amplification. Once the hole was completed it would not longer attract new ants and the number of digging ants would decrease over time. So order arrises from disorder via positive feedback and decay."

Yeah...I can see a PR problem there too...though they did manage to sell the idea of maggots and leeches....weird.

Sell eh? Let's keep this hush-hush, we might be sitting on a gold mine.

But if you were in a position where you felt no personal control, you were forced into a patient role and its associated state of helplessness and anxiety, and people were paying attention to you and/or doing things to you because of the cut on your foot and so-on and so-on, then that injury would have taken a predominant role in your life. In effect, it would have become one of the most significant things in your life at that time, and so would any pain or suffering resulting from it.

That's very true. Hospitals are such large, sterile, unfeeling places too. Perhaps it would be easier if we had more on smaller hospitals, though would certainly be bucking the trend.

I just spent the last 5 years working alongside nurses (until 2001)...mad as badgers, the lot of them. But I have to say, in my opinion, of all the sterotypically 'heroic' professionals, soldiers, firefighters, surgeons etc., nurses are true heroes.

I agree, teachers too. They are both so important yet they get treated badly by pretty much everyone. Unless they get better working conditions and pay we are just going to get a lower standard of people entering these positions, I personally want the person giving me injections to be of the highest standard possible.

[Glider]

Originally posted by Skye

It's a system of relatively simple things that interact to form a complex pattern. Weather, traffic flow, the CNS and ecosystems are examples. One of the principle ideas is that organisation can emerge from chaos simply by random and unorganised interactions. Another is that the sum of a system is, in a way, greater than the whole. Group dynamics are definately included, I'm reading a book on social insects. They are surprisingly complicated little critters.

Oh yes...I understand now. I've heard such things discussed in the context of cognitive neuroscience, particularly synergy. There is one theory which argues that conscious awareness itself is a synergistic epiphenomenon arising from the complex arrangement of neurones in the cortex. Where each neuron is a relatively simple thing, many together produce effects much greater than the sum of the parts. I can certainly see how that could be applied to social insects, particularly ants and termites. I seem to remember reading somewhere that ant and termite colonies are considered single organisms (or at least an argument that they could be). As a kid, my scientific investigations of these were limited to poking sticks into ant hills and termite mounds.

 

Sell eh? Let's keep this hush-hush, we might be sitting on a gold mine.

Oooh yeah!...I'd love to one day own a medical maggot ranch....y'know, just a li'l spread all my own. Out on the range all day, a wranglin' and a brandin'..."head 'em up!...Cut 'em out!" Yeehar!.

 

That's very true. Hospitals are such large, sterile, unfeeling places too. Perhaps it would be easier if we had more on smaller hospitals, though would certainly be bucking the trend.

I think that's an excellent idea. In the UK they're aiming for 'centres of excellence' which simply means huge 'super hospitals'. They're starting to look like factories. One of the major benefits of a smaller system is that there's no better way to spread 'super bugs' than to hold hundreds of sick people in an enclosed building with enclosed air conditioning. Smaller places, or at least large places spread out in many smaller buildings would provide natural barriers (e.g. MRSA blows off clothes in the outside environment). They'd also be much less imposing to the patient.

 

I agree, teachers too. They are both so important yet they get treated badly by pretty much everyone. Unless they get better working conditions and pay we are just going to get a lower standard of people entering these positions, I personally want the person giving me injections to be of the highest standard possible.

Bloody right too! In order to combat the chronic shortage of nurses here, they started employing hundred of nurses from abroad (particularly the Phillipines). I'm not for one minute suggesting that these are lesser nurses, but for pete's sake! It shouldn't be necessary to do that. All they have to do is to treat our own nurses properly. It says a lot about a government when, rather than aknowledging the work of our own nurses, they resort to 'importing' nurses who will do the same work for a lot less. Here's a couple of interesting statistics. In the last ten years 20% of all hospital beds have been closed due to dangerously low numbers of nurses. In the same period, 30% more managers were hired. There are now 1.7 managers to every open bed in the NHS. These managers have been employed to 'help' hospitals achieve the 'targets' laid down by the government so they can be seen to be keeping their campaign promises. Managers can't treat patients, they can only shuffle numbers and paper. It seems to me just a cynical political ploy in which it's more important to get the numbers right than to treat the sick. It's the same with teachers and the school league tables they have over here. It's more important to cram students through exams to achieve the 'right' pass numbers than it is to ensure the students understand anything. It really pisses me off sometimes. At University, there is a scheme of 'widening access'. The government wants a lot more people to go into higher education. To facilitate this, the traditional entry requirements are being dropped and a number of alternatives employed. In principle, this is a good thing. I think everybody has a right to education. The point that's being missed however, is that whilst everybody has the right to education, not everybody has the ability to achieve a degree (what would the value of a degree be if it was no harder than a certificate of secondary education? Not every school kid manages to get those either). However, the government (who's idea this is), will not fund Universities for the numbers of students who enrol, only for the numbers who pass. Can you see the clear conflict of interest there? As a consequence, lecturers are now teaching undergraduates who are barely literate! How can you teach somebody to degree level when they can't even string a sentence together or have trouble reading the recommended texts, much less understanding them? There simply isn't the time in 3 years to teach people a basic command of their own language (which they should have learned in school) and get them to degree standards of critical analysis and argument! What's worse is that many of these students seem to think they have an automatic right to a degree, simply by virtue of enrolling at Uni! Dagnabbit all!

 

Hmm...seemed to be getting a bit carried away there. Sorry about that, it's just I feel quite strongly about it....perhaps you could tell.:rant:

[Skye]

You need to settle down on a nice quiet maggot ranch out west (Wales perhaps?)

 

Social insects nest, such as termite mounds, have one reproducing organism (the queen), millions of her non-reproductive offspring and some males. In this situation it's pretty easy to conceptualise it as a super organism, with individuals being analogous to organs. In some species it is less clear cut, all worker honeybees (who are the queens daughters) are capable producing male eggs. Other workers will usually eat eggs they don't recognise as the queens, because they are more closely related to the queens sons (their brothers) than their sisters sons (their nephews).

 

The impetus for social insects forming colonies is thought to be haplodiploidy, in which females diploid while males are haploid, they result from unfertilised eggs (which are what worker bees produce). This means that fathers have no sons and sons get all their genes from their mothers. For the females it means that a she is more closely related to her sisters than her daughters, she shares 50% of their genes with her mother and 100% of her genes with her father. On average then, females share (50% + 100%)/2= 75% of their genes with their sisters. This only hold true if the queen mates with one male. If the queen mates with a unrelated male then the workers don't share 100% of their genes with him, so the percentage relatedness drop. Despite that, it seems that the first colonies formed because individual females spread their genes better by caring for their sisters rather than their daughters. The queen makes up for her disadvantage in only passing on 50% of her genes to her daughters by having sons who have 100% of her genes.

[YoungStrife]

Back to bones.

 

Are there nervs and blood vessles actually inside the bone? Because I heard that the bone melters are fallowed by those that repair nerve endings, THEN the bone builders....correct any mistakes I made, and elaborate..hehe

[Skye]

The main structure of one is a matrix of interwoven collagen fibres that contain crystals of calcium salts. This forms a sponge-like structure inside the bone. Blood vessels and nerves are able to enter the bones at various points and travel through channels in the spongy structure.

[Glider]

The impetus for social insects forming colonies is thought to be haplodiploidy....

Dang! I had to read it a couple of times, but I think I got it. It all seems very incestuous, in a Richard Dawkins kind of way. I suppose the 'hive drive' would provide a particular advantage in propagating a particular set of genes though. The measure of its success I guess, would be the millions of years such colonies have existed.

[Skye]

I recall reading that social systems are thought to have evolved around a dozen seperate times in insects, so there would have to be a good reason to do so. While social insects do seem to be more productive than individuals, which gives the system as a whole an advantage, it's probably more due the fact females are so much better off looking after their sisters. A female worker is actually being 'selfish' (in Dawkins' terminology) in looking after her sisters rather than her own daughters. She is helping to pass on more of her genes this way.

 

This is counter-intuitive to us, and a little tricky to get your mind around. I'll try to flesh out my explanation so it makes a little more sense. If a particular man and woman have a child the offspring, on average, share 50% of their genes with each other. This is because, as diploids, we have two sets of genes, one on each chromosome. These genes are fairly randomly divided up during the production of gametes, which combine to form offspring. So you and a sibling have a 50% chance of sharing any one gene, and thus share an average of 50% of your genes overall.

 

Female Hymenoptera (ants, wasps, bees, termites) are diploid like us, they have two sets of chromosomes. They get an equal amount of genes from each parent, in exactly the same way as we do. Males, however, only have one set of chromosomes, which they get from their mother. They result from a single unfertilised egg, which contains a random half of the females genes. When a male mates they pass on all their genetic information onto their daughter, and each daughter gets exactly the same genes as her sisters. This leads to the interesting part. If a male and female mate, all the female offspring are receiving the exact same genes from the father. This means that each female is assured that 50% of her genes are the exact same as her sisters. She also shares an average of 50% of the remaining 50% (i.e. 25%) of her total genes. This adds to give a total of 75% of genes are shared.

 

So a female is actually caring for more of her genes when she cares for her sister than her daughter. Presumably females that have done this have had an advantage in the past, spreading heir genes more effectively. Interestingly many species of Hymenoptera are solitary and don't form colony but can be induced to if they are put into an inclosure with only one nesting space. In some species colony structure varies, it may be a swarm of several queens and many workers, it may be a single queen giving rise to a colony of her offspring. In honeybees the queen alone can mate, workers can only produce males, and in ants (except poonerine ants) the workers cannot produce eggs at all. In these situation the queen will mate will several males, which reduces the relatedness of workers significantly, and also between daughters and their brothers. They are stuck with it, and their sisters sons (if they can produce eggs) are even less related to them so they tend to eat their sisters eggs, which reinforces the social structure. Honeybees sometimes break out into anarchy where all the workers start reproducing males, though this usually destroys the hive since no one is working. Anarchy aside though, most advanced social structures in insects function as a cohesive single entity.

 

Obviously this has an appeal for studying human social systems. One of the main ant researchers over the past 50 years, Edward O. Wilson, introduced the concept sociobiology, applying evolutionary principles to social science, which died with Social Darwinism. It also has alot of use is designing interacting robots. As decentralised information processor it can serve as a model for the brain. I find this very interesting because there are many areas where you get unexpected results.

 

When an ant finds a large amount of food it returns to the nest an gathers a group to retrieve it. The original ant is crucial to the retrieval (even if it barely retrieves any food) and if removed the retrieval of the food usually fails, even if the retrieval group has actually reached the food. I think these kinds of behaviour, which aren't heirachical but provide a structure to ant groups, are interesting in themselves but also show ways in which the brain could have an information processing structure that divides roles up due to chance events and provides an added level of complexity from uniform componants.

 

K I'm starting to ramble....