4 ms·
Blood Pumping Mechanism of the Hoof (2020)
- changoplatanero 5mo agoWhat about when the horse is sleeping?
- koziserek 5mo agothen you dont need that much circulation.
- cuechan 5mo agoI guess when the horse lays down the pumping force from the heart is enough to pump the blood back. Much less gravity to work against
- raffael_de 5mo agohorses sleep in a standing position. (https://www.petmd.com/horse/do-horses-sleep-standing https://www.petmd.com/horse/do-horses-sleep-standing)
- rramadass 5mo agoSee https://news.ycombinator.com/item?id=48247471 https://news.ycombinator.com/item?id=48247471
- cromulent 5mo agoThe calf muscle pump performs the same task in humans.
- rramadass 5mo agoRight; The Soleus Muscle Pump aka Soleal Pump aka Peripheral Heart aka Sural Pump. From https://en.wikipedia.org/wiki/Soleus_muscle https://en.wikipedia.org/wiki/Soleus_muscle ; Also, in upright posture, the soleus is responsible for pumping venous blood back into the heart from the periphery each time it contracts and is hence often called the skeletal muscle pump, peripheral heart or the sural (tricipital) pump. Soleus Pushup - https://stories.uh.edu/2022-soleus-pushup/index.html https://stories.uh.edu/2022-soleus-pushup/index.html and https://www.physio-pedia.com/Soleus_Push_Up https://www.physio-pedia.com/Soleus_Push_Up This is the science behind the Baithak aka Hindu Squat.
- signalbright 5mo agoPosts like this one are the reason we read Hacker News
- Paracompact 5mo agoI've been pondering for a while a question that is exceedingly unlikely to ever be answered within my lifetime, because as a prerequisite it assumes a framework strong enough to answer several very hard questions in philosophy, neuroscience, and information theory. And that question is: Is it possible even in principle for a conscious entity to have an instinctual understanding and awareness of every low-level detail comprising its design? > An extensive network of veins called a venous plexus are located on both sides of each of the lateral cartilages and in the sensitive structures of the hoof. The compression of these veins by the plantar cushion against the lateral cartilages or the coffin bone against the hoof acts as a “pump” to force the blood up the leg and back to the heart. A horse is an extremely sophisticated biological machine, but it has no idea what makes itself tick. It has some limited mental model of the world around it and that's about it. Humans fare little better, but at least can make inch-by-inch progress through scientific study. Such a creature that knew and felt itself perfectly, could at any point inquire the status of its own glycogen stores in its liver, could diagnose and micromanage its immune responses, could introspect accurately and with infinite recursion upon its own thoughts, seems hard to imagine, because if one were to set out to design such a creature, naturally its complexity would have to scale with the complexity it is attempting to self-model. Perhaps there is some sort of upper limit to the consciousness:complexity ratio that makes closing this gap impossible. (Or perhaps there isn't, and that would be just as fascinating.) If nothing else, I would like to read a Borges story on the subject. Such a creature might inevitably be doomed to the same fate as Funes the Memorious.
- Animats 5mo ago> Is it possible even in principle for a conscious entity to have an instinctual understanding and awareness of every low-level detail comprising its design? Access is possible, complexity limits what you can do with it. It's like having a JTAG port on a chip with a lot of test access. You can read the state of most of the gates, but now you're overwhelmed with data. Processing that data takes more resources than the system being monitored. At a larger scale, though, this starts to work. Modern industrial plants and cars have sensors all over the place, more than are really needed to operate the system. They're there to diagnose it.
- rramadass 5mo agoFar more interesting but relevant fact; Giraffes are at the very edge of physical adaption. In the fantastic Channel-4 TV series Inside Nature's Giants (https://en.wikipedia.org/wiki/Inside_Nature%27s_Giants https://en.wikipedia.org/wiki/Inside_Nature%27s_Giants) they dissect a giraffe and show how their anatomy/physiology is adapted to handle extreme blood pressure (because their heart needs to pump blood to the brain through the long neck against gravity). But that same pressure when sent down to the legs will burst their blood vessels. So how does cardiovascular adaptation work in this case? Read these to find out; 1) How giraffes deal with sky-high blood pressure - https://www.bbc.com/future/article/20210803-how-giraffes-deal-with-sky-high-blood-pressure https://www.bbc.com/future/article/20210803-how-giraffes-dea... 2) The Remarkable Cardiovascular System of Giraffes - https://www.annualreviews.org/content/journals/10.1146/annurev-physiol-031620-094629 https://www.annualreviews.org/content/journals/10.1146/annur... 3) How long limbs reduce the energetic burden on the heart of the giraffe - https://journals.biologists.com/jeb/article/228/20/jeb251092/369564/How-long-limbs-reduce-the-energetic-burden-on-the https://journals.biologists.com/jeb/article/228/20/jeb251092... 4) Giraffe dissection episode (must watch!) - https://www.youtube.com/watch?v=pkhztOqKYIc https://www.youtube.com/watch?v=pkhztOqKYIc PS: Inside Nature's Giants is one of the best scientific series which everybody should watch, particularly students. This is how evolution should be taught; all episodes on Youtube - https://www.youtube.com/results?search_query=inside+nature%27s+giants https://www.youtube.com/results?search_query=inside+nature%2...
- rramadass 5mo agoInside Nature's Giants: Racehorse dissection episode - https://www.youtube.com/watch?v=feAj2aspkIE https://www.youtube.com/watch?v=feAj2aspkIE
- beefandcheese 5mo agoAnd then we nail metal shoes on them.
- adiabatichottub 5mo agoA good friend of mine is a ferrier, or as he likes to say, "equine podiatrist". There's actually quite a lot to it. They are responsible for shaping the hoof and shoe in a way that corrects problems with the horse's gait. Each shoe is custom made and fitted to the horse, fashioned from a plain bar of steel. It takes years to become truly proficient at the craft.