Human anatomy, at first glance, often seems wrongly-engineered. After you've worked inside dozens of people, you begin to realize that everybody is unique — and nobody is "textbook" anatomy. Who knows what all this goop even does?!

If you ever get the chance, I highly recommend this humbling human experience. My hope is that my own cadaver is ripped apart by somebody as crazy/appreciative as me =D

“Nobody is textbook anatomy”

I know you’re exaggerating for poetic effect but this might actually be true in some parts of the human anatomy.

For example the description of the anatomy of vessels and anastomoses around the knee…I have had a professor tell me that the standard anatomical descriptions for this might all essentially be fiction. Basically the variation in some of these vessels over there is so high that the standard anatomical textbook description might be wrong.

That being said maybe the professor was wrong. I don’t know. But it was an interesting thing to think about.

I had an ingrown toenail fixed. There is a nerve that comes in and branches in two in the bug toe. In my toe it branches into three!

Another example is that of sciatia, which is much more prevalent when your sciatic nerve takes one particular path to get through the glutes. Other routed methods and sciatia is much less likely to be debilitating.

So that's the reason behind the dick pics. I thought it was just to show off, but it's for identification. Makes total sense now.

A form of biometric authentication, perhaps? Assume one has a spare CT scanner or some such thing, and doesn't mind discriminating against roughly half of the population.

  > Even identical males twins don't have the same penis structure/routing. Thanks for sharing your own personal example (I am the twin, in mine).

For the axillary approach to brachial plexus blocks, we tried to elicit paresthesias from actual needle impaction on nerves and then pulled back a tad and injected a bolus of anesthetic.

We did that repeatedly, aiming to deposit anesthetic near each branch of the plexus.

Failing that, hitting the brachial artery with the needle and then continuing to advance the needle until no blood could be aspirated, injecting half the intended volume of anesthetic (2% lidocaine with epinephrine 1:1000) behind the vessel, then withdrawing the needle until no blood could be aspirated and then depositing the remainder of the anesthetic on the front side of the artery was the technique of choice.

Diff'rent strokes.

What this thread is talking about is things like extra fingers, missing or extra nerves and muscles, and varying structural differences.

I recently started learning a lot about the muscular and nervous system in the hip area. Even on Wikipedia you routinely read things like „this muscles is missing in x% of population”. It blew my mind that there is so much difference to our internal structure.

One of the most incredible exhibits I've seen are the anatomical tables on display in the Royal College of Physicians museum in London. When I walked into the room there were these 3-4 "doors" with what looked like shadows of people on them. The more I looked, and the more I understood what I was looking at, the more amazed I became.

The museum, and building I think, was closed for a few years but understand it's back open again.

https://history.rcplondon.ac.uk/collections/art-and-objects/...

The tables are visually spectacular. They show the recognisable form of the human body laid out flat, as if illustrating a book. The nerves, veins and arteries on display were dissected at the University of Padua’s famous anatomy theatre in the 17th century, and skilfully arranged on varnished wooden panels.

And I think with "most of the cells in your body are not you" and gut biomes and more...

I think everyone is their own ecosystem too.

It and several of the nerves preceding it, which originally innervated the branchial arches, remain different in nature from the following nerves (spinal nerves + cranial nerves XI and XII), whose original main purpose was to innervate the somatic muscles. This difference is more important than whether the nerves happen to exit the central nervous systems between adjacent vertebrae or by holes through the cranium (which are the result of the first vertebrae becoming fused to the occipital bone).

The nervus vagus and its associated ganglia of the vertebrates has a correspondent in the nervous system of most animals, including the arthropods, as a vegetative nervous system of the gastro-intestinal tract, which is connected to the central nervous system from the head, e.g. with the tritocerebrum of the arthropods.

As for "chance of being hacked apart," anybody can donate their cadaver to science — most facilities require prior enrollment and will recover the corpse, nationwide.

You might end up sold into scientific experimentation... if you're morbidly obese (e.g.) you won't be used for student anatomy (if you care).

Not my cup of tea, personally, but my ultimate point is you might get used in something you disagree with. Look into the history of cell lines used in medicine for some of the controversy and perpetual pain for surviving family members, as an example.

Models of circulatory systems with plastesizers and then all other flesh removed — incredible and complex and unique-to-each-human.

2008/9 I did anatomy prosections and had an absolute blast, but ultimately did not become licensed.

Don’t know what to do with the information I have discovered in the end but a good reminder to pause and reflect occasionally with the hope that we may not enable whatever the next “great idea, damn the costs” is.

Arousal is especially interesting because you can compress a nerve in the right way and experience something you don’t actually feel or want to feel. Feelings, however, are not the “mind”, i.e. the self-directed, persistent and conscious entity.

I think it’s important to say this because people often fall into the trap of thinking physiological responses are indicative of consciousness.

Another cool thing about the vagus nerve is what happens when people get vagotomy (from Wikipedia)

> Researchers from Aarhus University and Aarhus University Hospital have demonstrated that vagotomy prevents (halves the risk of) the development of Parkinson's disease, suggesting that Parkinson's disease begins in the gastrointestinal tract and spreads via the vagus nerve to the brain.[24] Or giving further evidence to the theory that dysregulated environmental stimuli, such as that received by the vagus nerve from the gut, may have a negative effect on the dopamine reward system of the substantia nigra, thereby causing Parkinson's disease

Almost kissing cousin to ADHD....

if it does, then the vagus nerve orchestrates the brain-body connection.

the mind-body problem, or if you prefer the mind-brain problem, remains unsolved. and apparently, mind-brain confusion persists as well.

I had the exact same reaction: "mind" as in "mind-body" for me refers to things such as reasoning, qualia, intentionality, the fact that neural patterns somehow receive "real meaning".

The mind may or may not be immaterial. This age-old question has not been resolved in any way, not even close.

you are presenting an untestable-and-only-descriptive-hypothesis as a theory.

if we assume that what we know about it today is all there is, then yes, it must be your way. But why assume that what we know is all there is, that assumption has always turned out wrong for thousands of years? Better to say "we don't know what the nature of the mind is or where it comes from beyond the clear evidence that it's tied to the brain."

It seems very possible the mind is just a superstitious artifact but this idea persist in various forms because to let go of it truly means the lights go out at death. We seem incredibly good at telling ourselves stories to deny that reality.

I had built a "vagus nerve stimulation app" a while back which used vibration to enhance calm. I did some measurements comparing this vibrating stimulation to neurofeedback with a Muse device, and the results seemed positive, but because we couldn't say specifically which mechanism was being triggered, and that it wasn't more than just "listening to calm music", we didn't pursue it.

> However, some people have taken the vagus nerve’s expansive bodily influence as an invitation to engage in pseudoscience. In some corners of the internet, so-called polyvagal therapy — physical or breathing exercises that some claim reset the vagus nerve — is proposed to address(opens a new tab) just about any disorder of the mind or body. There’s little to no evidence that these popular remedies are anything but placebos.

Apollo Neuro claims to have lab data proving efficacy: https://apolloneuro.com/pages/science

Even if it's more of a placebo effect, I still enjoy the benefits of devices like this.

What explanations might helps us understand why evolution went in that direction?

What is our most distant ancestor that does not have the split?

Well, this understanding, if true, could help explain why the severe-debilitating pain level I've had would very easily cause me to get completely lost in the pain - where I couldn't get my mind going, couldn't focus past the pain, would be lost and fully distracted by the pain if I didn't 1) keep my activity level as low as possible (even slight movement of my neck would strongly worsen the symptoms of Eagle's syndrome, particular to the right - a commonly described symptom that one side is much worse), and 2) if I had had any inflammatory foods during the prior 2-3 days or 5 days if dairy.

Now my struggle is, now that my nervous system isn't so interfered with with my vagus nerves' signaling no longer being interfered with - my nervous system is working far stronger now, so I feel the remaining few areas of pain far more strongly - and along with that emotionally the experience is far harder as well, far more aggravating; and I arguably no longer get as easily lost in the pain anymore, but now that I am more often connected to my mind, the remaining more strongly experienced pain is more constantly disruptive - whereby the disconnect otherwise was arguably a sort of coping mechanism; being lost in pain is not fun, but at least then routine could act as a functonal crutch.

The biggest problem now though is it is even more difficult to get my mind focused on a specific task that I need to get done, having had severe executive dysfunction that had slowly been improving over the years as I played whack-a-mole to knock out the next strongest sources of pain - but now trying to organize and get together what's needed to book next diagnostics for next likely needed treatments to get last 2-3 major-excruciating remaining pain sources has been so difficult now, the uphill battle has turned into a steep cliff; the biggest problem is I am in Canada, Ontario specifically, and the knowledge and competency-critical thinking here is absolutely abysmal - where I've had to spend likely now over $800,000 for medical treatments in the US over the last ~8 years, and now struggling to find competent dentists - made worse by a dentist 1+ year ago - lastly being bounced around I think to 5 different dentists now the past 3 months.

My story is more complex than this however. My issues with pain only started after "successful" LASIK eye surgery ~12 years ago caused my nervous system to get overwhelmed - causing central sensitization - was the tipping point or the "final straw that broke the camel's back." Prior to LASIK my mind could handle suppressing whatever underlying pain the injuries and nerve compressions I had; so there is definitely a factor of compounding and arguably amplification (along with hyperalgesia, a hyperesensitivity to pain) between different the eyes and the rest of the body-brain.

I'm at my wit's end, and as pain has localized, unmasking the remaining pain sources more strongly, it appears there's a possibility while LASIK may have been the impetus - it may have been the teeth damage-specific teeth pain but overall bite occlusion causing severe sensitization via disruption of my reflexes-autonomous nervous system, essentially TMJ-TMD but only problems runaway guarding-muscle spasming that's compressing nerves - and then perhaps TMJ-TMD guarding compounding with the Eagle's syndromes; and then perhaps also with the corneal damage that happens in 100% of LASIK surgeries, of which there is nothing more I can try to reduce that as a source of pain.

I ended up getting corrective soles and a mouth guard, and with the mouth guard specifically, I immediately went from 100% to 30% pain, and still recovering.

The nervous system and the interconnectedness of our bodies is impeccable. Throughout my recovery I learned so much about my own bodily systems. I recommend everybody, especially desk-jobbers, to see a qualified orthodontist for their chronic neck/shoulder/back pains. You will be surprised what you find out about the damage, and how fast recovery might come.

Mouth guard helps prevent too much pressure being applied to the neck, which gives pain relief all over.

As for soles, I had one foot that was facing outward while walking, which was identified by a physio to be due to hamstring tightness. But why is the hamstring tight? Automatic posture correction by my body! Since getting mouth guards, I've also been enjoying shoes with wide toeboxes and no rise too, which helped me correct my gait and reduce the impact on my hip.

I've had an aweful lot of procedures and meds over 30 years, over 200, including 12 spinal procedures in 12 weeks when an attempt to deliver steroids to the C7 dorsal horn tore my dura mater. Very unpleasant.

It's really hard, as you say, to find good medical practitioners when you've got chronic nerve pain. They have to understand the relationship between hyperalgesia, allodynia (things that should not hurt hurting like crazy), movement (and lack of same) and meds, physio and psychs. Other injuries get involved once your brain is programmed to hurt you, and post surgical care involves more hard drugs to avoid sensitisation, leading to more complex drug tapering to get off the damn opioids (which only make chronic nerve pain worse paradoxically).

You say "I'm at my wit's end", and I've been there, past it and back again. You need to see a pain psychologist, a specialist psych. They can teach you "Jedi mind tricks" that may work for you. Things like how to focus your conciousnes into a bit that's NOT hurting. How to use disassociation to help getting day-to-day tasks done when you just want to curl up in a ball and cry.

I also strongly suggest you get in touch with other chronic pain patients. It's incredibly helpful to know you're not a weak freak who is a wimp and a weakling. To hear that other people have the same struggles. And to hear strategies for doing things that don't hurt as much.

Here in Brisbane people used to meet once a year in King George Square, for "Colour the World Orange" day. Three of these people are now friends who know what I mean by "it's not a good day". I found actually meeting other sufferers in the flesh to reinforce knowing that I'm not alone with this curse, other people struggle too.

And one from that group is in remission. We're all living vicariously through her, as this gives hope. Hope is what we all need.

On top of chronic pain, I had (and still have but is greatly reduced) muscle clenching on the left side of my body - for some reason my body on the left side is clenching up, with this constant pulling on my head, pulling down and to the left. I also have severe TMJ, again on the left, and constant headache, light sensitivity, difficulty focusing and fatigue. It was truly horrible - imagine going through life with an extremely strong pull on your head and body. Your posture is messed up so physically, you look like a wreck, and sitting is painful as is standing. Also, you are just fighting this pull every second of the day. It never ends and you constantly have to think about it and ways to reduce the pull and the pain.

I worked with physical therapists and orthopedists for decades to try to figure out what was going on, but nothing worked. So about 8 years ago (I'm 50 now, so it was around my 42 birthday), I finally realized that I needed to look beyond the obvious causes of these types of problems, and explore almost everything, really ramping up the number and types of doctors I was seeing. Saw many types of docs: pain specialists, TMJ docs, gastroenterologists, ENT's (I have throat tightening and stomach issues too), neurologists...

Eventually, like you, found that many of my issues were from compressed nerves. And yeah, it's a struggle for you and the docs to find the right ones, but once you do, it makes a big difference. I'm not 100%, but I'd say I'm 60% there, and it's definitely changed my life, and is visible both physically and socially.

Of course, every person's body and causes of health-problems is different, so what helped for me may not help for you, but seems like you're on the right path. Keep searching, and would suggest being scientific about the process (this really helped me). I may write about my experience one day, so if you have any questions, let me know. And best of luck

Exercise definitely helps but it doesn’t actually seem to turn the nerves off, just desensitize them.

Sitting is very painful as I get pain in my sit bone and shooting numbness down my leg and all the way into my foot.

I have almost given up and accepted that I will be a cripple for the rest of my life. I live in British Columbia where the medical system is OK, but not near world class and all of the ambitious doctors have went to the USA.

I have a very bad bite which makes me suspect that my whole posture is messed up from the top down.

Actually yeah, have been basically eat a low-ish inflammatory diet for ~25 years. Ever since in my twenties, realized that I had some major health problem, took my general health very seriously, and have been eating healthy since then (eating a lot of fruits and vegetables, whole grains, and only eating meat/fish once per day). In addition, have been exercising regularly too. This definitely all helps, because I would have felt completely miserable if my general health was also bad.

But seems like when it's a damaged nerve, then diet, exercise, and massage/accupressure can only do so much. The nerve is always firing and basically an electric circuit that is always on. The method that was worked in my case is to find a way to shut off that circuit.

And glad you found a low inflammatory diet helped you:)

I just wonder if there is a drug which can reduce nerve sensitivity, although I guess this is a well explored topic for you.

I have not continued the carbamazepine. In both cases, I used it for about a couple of weeks, and then stopped using to test if there would be a flare-up (and there was none).

I have an enzyme deficiency called Partial PNP Deficiency which slows the speed I can metabolized these low level purines. When I eat these food I have full body pain as well as mood issues.

They add these to nearly every processed food in forms as innocuously sounding as "malted barely extract".

I used to need drugs, now I just need to watch what I eat (and watch other things in my environment like stress).

[1] https://en.wikipedia.org/wiki/Guanosine_monophosphate [2] https://en.wikipedia.org/wiki/Disodium_inosinate

@computerdork do you have a tongue tie/lingual frenulum or narrow airways/diaphragmatic dysfunction? These things can cause extreme issues with the fascia that lead to things presenting in such a manner.

If you’ve made it to teens/adulthood, it’s typically missed by fucking everybody in the medical profession.

Neck strain and tmj can be related as well from the overuse of muscles.

I'll look more into both these, Thanks!

But, this is how tinnitus is handled. You have to relax and not be hypersensitive to it, because there is a feedback loop, and you don’t want to contribute to it.

Best wishes. Pain is a difficult thing to have to deal with.

"Relaxing" will either slow glutamate release or increase GABA release. Processed foods often contain glutamate as a flavor enhancer.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8113735/

Fellow ear ringer here. My issue is with high GTP.

Re: Tinnitus -

Interesting thought to put forward, thanks.

If you still have issues with tinnitus or hypersensitive hearing, look into Berard AIT (Auditory Integration Train) - and where there's a book called "Hearing Equals Behavior: Updated and expanded" that details it, and a sound treatment that can help with all that you said.

Anyone have success with these for anxiety/depression

Ultimately if you think it’s working then it’s working.

A lower risk way is probably breathing techniques and meditation apps.

> However, some people have taken the vagus nerve’s expansive bodily influence as an invitation to engage in pseudoscience. In some corners of the internet, so-called polyvagal therapy — physical or breathing exercises that some claim reset the vagus nerve — is proposed to address(opens a new tab) just about any disorder of the mind or body. There’s little to no evidence that these popular remedies are anything but placebos.

It happened to me once, ten years ago (probably due to a severe kidney stones incident but we never found out) and I passed out, on the ground, in front of my girlfriend.

My layman understanding is this: pain is too strong, the mind-body decides to simply turn the mind off.

Weirdly enough about one minute late I began to "think" again: laying on the floor and... Pain was gone.

That was a decade ago so... Whatever!

Working 7 days a week makes your vagus nerve sensitive and under stress can shut you down as a defence mechanism.

Never knew this, have always advised friends to be very careful when under stress for long periods of time.

I'm surprised to see it affects 20+% of the population because I've never met anyone who knew what I was talking about when I said "sorry, light makes me sneeze"

Lights don't trigger a full sneeze if I don't need to but it always helped.

My personal feeling on over-medication of our society is that it encourages more offspring from less-successful brains. (however one might determine that).

But that's just my ¢¢

"It is possible to stimulate the nerve fibers with a mild electrical pulse by surgically inserting electrodes into the chest or, more simply, clipping them to an earlobe."

The electric pulse stimulates the release of catecholamines and purines which initiate and heighten nerve signals along the pathway,

The "simple" way they describe the vagus nerve leads to an inhibition of creative thinking in the field of psychiatry and health.

[1] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10843545/ [2] https://link.springer.com/chapter/10.1007/978-3-540-79090-7_...

Slowly move your eyes to any fixed direction (say, to the right) and keep your eyes open, staring to the right.

This will initiate a yawn or deep sigh in most people, stimulating vagus nerve.