Posts tagged bones

Does milk leech calcium from bones? — Asked by Anonymous

Okay, third time I’ve gotten this question.

As a dairy science humaoid: NO, IT DOES NOT.

Unless you have been drinking only milk your entire life, and then suddenly drink only water, there is no plausible way I can think of that milk would leach calcium from your bones. And even THEN, you’d only leach it from your bones for a few days/weeks at most, if you had other calcium sources. Even if those sources are harder for the digestive system to access than milk, they probably have more calcium to make up for it, and are just fine in the long run.

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In the end you need plenty of calcium AND VITAMIN D for both your bones and guts, and milk is an alright source for those.

But honestly, rich leafy greens like kale, cheese (especially parmasean and its ilk), sardines, and tofu are all excellent sources of calcium, and don’t have the same sugar content as milk.

Yes, most of them are much higher in fat content, but that means that they remind your brain “SHIT SON THAT’S GOOD WE HAVE ENERGY FOR THE NEXT 8 HOURS!” and not “OH NO! NEED LONG-SUSTAINING FUD, ONLY HAVE SUGARS AVAILABLE!”

Regardless, in the quantities that most people consume it, milk does not leach from the bones, it is NOT the best source of calcium, it is not necessarily bad, and not always the best.

I love cows, I love dairy science, LOVE cheese, and I love my home state. I am also an eternal skeptic and believer in science, and do not appreciate the Dairy Council taking my money and turning it into what amounts to propaganda in some campaigns.

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Seek the truth for yourself. Learn how science and critical thinking work, and read the studies people claim “support” their viewpoint. Figure out if they’re correct or not, but don’t assume you know how to do so until you actually understand how science and critical thinking work.

You’re you’re own best advocate.

image

tl;dr: No, it doesn’t. But don’t believe that it’s the miracle drink it’s marketed as, either - especially if you’re past adolescence.

biomedicalephemera:

Reginald Southey with human and monkey skeleton
Albumen photograph by Charles Lutwidge Dodgson (nom de plume Lewis Caroll, author of Alice in Wonderland), 1857.
Reginald Southey was an English physician who invented a specialized cannula (tube) for draining the excess fluid from limbs suffering from edema (dropsy). He also apparently served on England’s “Lunacy Commission” so…there’s that. Southey was lifelong friends with Charles Lutwidge Dodgson and was the one who encouraged him to take up photography.
The pensive expression on Southey’s face betrays the fact that he’s standing with his arm around a skeleton rather than a live human. The composition of the photograph and the portrayal of the abnormal as mundane strikes me as incredibly reminiscent of the worlds Dodgson created in his writings.

biomedicalephemera:

Reginald Southey with human and monkey skeleton

Albumen photograph by Charles Lutwidge Dodgson (nom de plume Lewis Caroll, author of Alice in Wonderland), 1857.

Reginald Southey was an English physician who invented a specialized cannula (tube) for draining the excess fluid from limbs suffering from edema (dropsy). He also apparently served on England’s “Lunacy Commission” so…there’s that. Southey was lifelong friends with Charles Lutwidge Dodgson and was the one who encouraged him to take up photography.

The pensive expression on Southey’s face betrays the fact that he’s standing with his arm around a skeleton rather than a live human. The composition of the photograph and the portrayal of the abnormal as mundane strikes me as incredibly reminiscent of the worlds Dodgson created in his writings.

biomedicalephemera:

One of these things is not like the other…

First row: Walrus (Odobenus rosmarus) skeleton
Second row: Hooded seal (Cystopkora cristata) skeleton
Third row: Dugong (Dugong dugon) skeleton, Brazilian sea lion (Otaria flavescens) skeleton.

*Skulls depicted are of species in the same genus as the skeleton.

Sirenia (manatees, dugongs, and sea cows) and Pinnipedia (the seals, walruses, and sea lions) are often seen as very similar, but they came from very different lineages.

While both came from land mammals (just like all sea mammals), the pinnipeds evolved from a bear-like ancestor, who returned to the sea around 28 MYA. They’re Caniformidae, or dog-like Carnivora.

The sirens evolved from the same ancestor as the hyraxes and elephants, and returned to the sea around 50 MYA. They’re only distantly related to Cetaceans and Pinnipeds.

Vergleicheende Osteologie. Edward D’alton, 1821.

Bone types

Top: Metacarpals (long bones) and carpals (short bones)
Second row, left:Left ulna (long bone)
Second row, right:Scapula and sternum (flat bones)
Third row, left: Sagittal section of the knee joint, including the patella (sesamoid bone)
Third row, right:Thoracic vertebrae (irregular bones)
Bottom: Complete Skeleton

Bones are classified into five groups, organized by shape.

Long bones are longer than they are wide, and are subjected to most of the load-bearing responsibilities in everyday life. These include the humerus, radius, and ulna (arms); fibula, femur, and tibia (legs), as well as the phalanges (fingers and toes), metacarpals (hands) and metatarsals (feet).

They grow from the epiphysis (growth plate) at either end of the bone, and failure of these bones to grow causes the majority of dwarfism cases.

Short bones are as wide as they are long, and provide support, but do not bear heavy loads or move much. These include the tarsals (feet) and carpals (hands/wrists).

Flat bones are broad bones that provide protection to organs, and large areas for muscle attachment. These include the bones in the skull, the ilium,scapula, sternum, and ribs. The flat bones consist of two layers of compact bone, surrounding a layer of cancellous bone, where the majority of red bone marrow exists. In adults, most red blood cells are produced in the flat bones.

Sesamoid bones are bones within tendons, which pass over a joint. The most familiar sesamoid bone is the patella, or knee-bone. These bones provide protection to delicate joints.

Irregular bones don’t fit into any of the above categories. The mandible and vertebrae are irregular bones.

Images:

Atlas and Text-book of Human Anatomy. Dr. Johannes Sobotta, 1914.
Anatomy: Descriptive and Applied. Henry Gray, 1918.
A Series of Engravings, representing the Bones of the Human Skeleton. William Cheselden, 1819.

Illustrations of the branchial (pharyngeal) arches in the human

Top: Adult female with fully-formed structures superimposed to show the adaptations present in humans

Bottom: 28-day embryos, external and internal

When vertebrates develop, the pharyngeal arches are pairs of outpouchings in the embryo. In fish, they go on to form gills, and in other vertebrates they take many different forms. The different development paths of the pharyngial arches can tell us a lot about the evolution of vertebrates.

All vertebrates start with basically the same form, and all have six pairs of mesodermal tissue lumps coming out of their crudely-developed tadpole-ish bodies. In humans, the pharyngeal arches appear in week 4 after fertilization. They then proceed to develop at different speeds, but their end forms are many of our neck and head structures.

Every pharyngial arch has a cartilage stick, muscle component that differentiates from the cartilage, an artery, and a cranial nerve.

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The first arch is closest to the embryo head, and the numbering goes down the body from there.

The first (hyomandibular) arch forms the maxilla, mandibular form (but not the mandible bone), incus and malleus (two of the three ossicles in the ear), auditory tube, muscles of mastication (chewing), trigeminal nerve, and external carotid and maxillary arteries.

The second (hyoid) arch forms the muscles of facial expression, buccinator muscle, stapes (the third ossicle), stapedius (the smallest skeletal muscle, which stabilizes the stapes), part of the hyoid cartilage,  facial nerve (VII), and hyoid and stapedial arteries.

The third arch forms the rest of the hyoid, the thymus, inferior parathyroids, glossopharyngeal nerve (IX), and the common and interior carotid arteries.

The fourth arch forms the cricothyroid muscle, the muscles of the soft palate, thyroid and epiglottic cartilage, superior parathyroids, vagus (X) and superior laryngeal nerve, subclavian artery and aortic arch (the 4th left and right aortic arches).

The fifth arch does not form any significant structures in the human - it joins with the fourth arch and forms the part of the thyroid that creates C-cells.

The sixth arch forms all intrinsic muscles of the larynx aside from the cricothyroid, the cricoid and arytenoid cartilage, vagus nerve (X) [with fourth arch] and recurrent laryngeal nerve, pulmonary artery and ductus arteriosus (the 6th right and left aortic arches.)

By the beginning of the second month of pregnancy, the arches no longer look like every other vertebrate out there, and the embryo is now called a fetus. Though it will still be several more months before the fetus looks distinctly human and a layperson could tell the difference between it and a great ape fetus, the pharyngeal arches have set off to form the structures that allow us to survive as a species.

Images:

Die Wunder Um Uns. Artur Furst, 1911.
American Textbook of Obstetrics. Edited by Richard C. Norris, 1895.

currentsinbiology:

Ancient Human Oral Microbiome Found in Dental Calculus
An analysis of ancient oral microbiome ecology and function, led by the University of Zürich, the University of Copenhagen, and the University of York has discovered a microbiome preserved on the teeth of skeletons around 1,000 years old. The dental calculus preserves bacteria and microscopic particles of food on the surfaces of teeth, effectively creating a mineral tomb for microbiomes.
The research published in Nature Genetics reveals that unlike bone which rapidly loses much of its molecular information when buried, calculus grows slowly in the mouth and enters the soil in a much more stable state helping it to preserve biomolecules. This enabled the researchers, led by Dr Christina Warinner, to analyse ancient DNA that was not compromised by the burial environment.

currentsinbiology:

Ancient Human Oral Microbiome Found in Dental Calculus

An analysis of ancient oral microbiome ecology and function, led by the University of Zürich, the University of Copenhagen, and the University of York has discovered a microbiome preserved on the teeth of skeletons around 1,000 years old. The dental calculus preserves bacteria and microscopic particles of food on the surfaces of teeth, effectively creating a mineral tomb for microbiomes.

The research published in Nature Genetics reveals that unlike bone which rapidly loses much of its molecular information when buried, calculus grows slowly in the mouth and enters the soil in a much more stable state helping it to preserve biomolecules. This enabled the researchers, led by Dr Christina Warinner, to analyse ancient DNA that was not compromised by the burial environment.

Hey, I´ve got a question for you regarding bone marrow :3 I´m suffering from a genetic condition called Thalassaemia, which affects and athrophies the bone marrow. I´m suffering from a mild form, but I don´t know much about my disease since it´s really really rare in Germany. My question: I often suffer from searing bone pain, and my dodtor didn´t know if the Thalassaemia caused it. I didn´t find any info on the web, and was wondering if you happened to know anything about Thalassaemia :3 — Asked by Anonymous

I’m surprised your doctor doesn’t know more about thalassemia! It’s most common in the Mediterranean region, which isn’t that far from you guys.

In fact, the name comes from the Greek “Thalassa” and “haemia”, meaning “sea” and “blood”, respectively.

If the thalassemia that you have (there are tons of versions, so it’s hard to tell you exactly) is affecting your bone marrow, of course it makes sense that you would experience bone pain - the nociceptors in bone marrow and endostium comprise both myelinated and unmyelinated sensory neurons, so it’s not uncommon to experience both sharp, shooting, instant pain, as well as prolonged, dull (but often serious) somatic pain, when the marrow is affected.

If you have a bit of medical knowledge, Medscape has some good information on both beta thalassemia and alpha thalassemia, and the Thalassemia Foundation has some good information covering all of the known variants.

Top: Three-toed sloth (Bradypus tridactylus) skeleton and depiction
Bottom: Two-toed sloth (Choleopus hoffmanni) skeleton and depiction

Despite their superficially similar appearances, and their overlapping ranges, the two-toed and three-toed (well, two-fingered and three-fingered, as they all have three toes) sloths had very different evolutionary paths, and only came out so similarly due to convergent evolution, thanks to their rainforest habitat. They are not very related at all, it turns out. Their last common ancestor (LCA) existed around 39 million years ago (mya) - to put that in perspective, the LCA of ALL current mammals (humans, bats, whales, sloths, all of us) was probably around 65-60 mya, and the LCA of humans and chimpanzees was only 9 mya! Seriously, they are NOT very related. They’re both about as related as they are to the other members of their order - the South American Anteaters.

The two-toed sloths evolved from the ancient Megalonychidae, which includes the Megalonyx and other skeletal giant sloths, whose ancestors lived in South America between ~7 mya and 5000 years BCE. Though obviously not helped by the new immigrants, the giant sloths had already suffered significant declines to their population due to environmental changes by the time that humans arrived. We may have eaten a few here and there, but we did not cause their extinction, unlike many of the giant Pleistocene mammals of North America. These days, there are two species of two-toed sloth - Hoffman’s and Linnaeus’.

Three-toed sloths, however, we’re not quite sure about. Either they evolved in ways we don’t have complete links to, or they evolved from specimens that didn’t leave fossils that we’ve found yet. Like two-toed sloths, we do think that they dwelt on the ground until the Holocene (~12,000 years BCE), but we don’t know for sure. However, around that time, the savannahs and woodland/prairie environments of a lot of Central and South America became replaced by rainforest, which would have caused evolutionary pressure for them to move to the trees. Currently, there are four species of three-toed sloth - the pygmy (critically endangered), pale-throated, brown-throated, and maned.

Both creatures are slow, arboreal (tree-dwelling), and have many insects, fungi, and blue-green algaes (which aren’t actually algae at all…) growing from their fur. The two-toed sloths are slightly quicker than the three-toed sloths (approximately 1650 and 800 ft/hour, respectively - at least on land! Three-toed sloths are actually quicker swimmers than they are on the ground, and two-toed sloths are not so good at the swimming). They generally (but not always) eat different tree species, and often overlap ranges.

operatory5:

Left femur of a confederate soldier, white male, exhibiting attempts atrepair of a gunshot fracture of the upper third. Private E.W. A, CompanyG, 5th Regiment, Florida. Physician unknown. Civil War, Gettysburg,Pennsylvania. Pathological specimen 1938.

From one of the otisarchives (National Museum of Medical History). Not sure which one.

operatory5:

Left femur of a confederate soldier, white male, exhibiting attempts at
repair of a gunshot fracture of the upper third. Private E.W. A, Company
G, 5th Regiment, Florida. Physician unknown. Civil War, Gettysburg,
Pennsylvania. Pathological specimen 1938.

From one of the otisarchives (National Museum of Medical History). Not sure which one.

Comparative anatomy of the Bactrian and Dromedary Camels, and the human.

Humans domesticated Bactrian camels (Camelus ferus) over 4500 years ago, and Dromedary camels (Camelus dromedarius) even earlier - around 4000 BCE, or 6000 years ago. Domesticated Dromedary camels are so ancient that even the first dynasties of Egypt were thought to use them, from archaeological remains.

While Dromedary camels have survived relatively unchanged in the wild, Bactrian camels have been significantly altered by domestication. They’re shorter, far more amenable to human interaction, and have been bred to have longer fur and greater milk output. There is over a 3% difference in the genetic code between domestic and wild Bactrian camels - more than exists between humans and chimpanzees.

Comparative anatomy as applied to the purposes of the artist. Benjamin Waterhouse Hawkins, 1883.

centuriespast:

Bell, William H. (attributed to)American (1830-1910)Specimen No. 2749. Right Humerus and Elbow, Necrosis of the Entire Humerus Following Gunshot Fracture of the Epiphysisca. 1863Photograph
Amherst College

centuriespast:

Bell, William H. (attributed to)
American (1830-1910)
Specimen No. 2749. Right Humerus and Elbow, Necrosis of the Entire Humerus Following Gunshot Fracture of the Epiphysis
ca. 1863
Photograph

Amherst College

biomedicalephemera:

Fig 1: Front side of Os Femoris (the femur bone)Fig 2: Back side of Os FemorisFig 3: Underside of Patella, where it moves against the Os Femoris
The femur is, by most measures, the strongest bone in the tetrapod body. Its articulation with the acetebelum of the pelvis forms the freely-moving synovial hip joint, and its articulation with the tibia and patella at its distal end forms the knee joint. These joints accommodate walking, running, and jumping, which are critical activities for the survival of most tetrapods.
At the bottom of the front-facing femur (Fig 1), you can see an articular depression between the two condyles, called the patellar surface. This is where the patella rests. The deeper notch in the back of the femur (Fig 2) provides an articular surface for the many ligaments of the knee joint.
The patella's primary purpose is to provide protection to the crucial structures in the knee. The synovial joint is strong, but if it got damaged when we were still living off the land, it could mean death from an inability to farm or hunt.
Cheselden’s Plates of the Human Bones. William Cheselden, 1814 reprint.

biomedicalephemera:

Fig 1: Front side of Os Femoris (the femur bone)
Fig 2: Back side of Os Femoris
Fig 3: Underside of Patella, where it moves against the Os Femoris

The femur is, by most measures, the strongest bone in the tetrapod body. Its articulation with the acetebelum of the pelvis forms the freely-moving synovial hip joint, and its articulation with the tibia and patella at its distal end forms the knee joint. These joints accommodate walking, running, and jumping, which are critical activities for the survival of most tetrapods.

At the bottom of the front-facing femur (Fig 1), you can see an articular depression between the two condyles, called the patellar surface. This is where the patella rests. The deeper notch in the back of the femur (Fig 2) provides an articular surface for the many ligaments of the knee joint.

The patella's primary purpose is to provide protection to the crucial structures in the knee. The synovial joint is strong, but if it got damaged when we were still living off the land, it could mean death from an inability to farm or hunt.

Cheselden’s Plates of the Human Bones. William Cheselden, 1814 reprint.

HOKAY NO MORE HEIGHT QUESTIONS

<3 I’ve gotten about 15 anons (and, thankfully, several non-anons) in the past 2 hours, and while I’d love to help you all, I really really cant.

Trust me, you’re cool even if you’re below average or way above average or two feet tall! Don’t worry about it, and if you want to know the reasons why, your doctor knows way more than me ^_^

I want to put my two cents in. I'm 17 as well.. almost 18, female and I'm 5'1 .. I exercise but I don't eat well is there a chance I'll grow at least a bit? — Asked by Anonymous

I mean, there’s always a chance if you’re not above the age where your epiphyseal plates fuse, you’re probably at your adult height, or close to it.

…just in case your bones have got some growth left in them, get some sun and eat some fruits and veggies, yes? Even the winter sun has lots of vitamin D in it, and you REALLY need proper vitamins and minerals to grow to your complete potential.

While there’s a good deal of genetic variation in the field, the fact that vitamins and minerals are so intrinsic to your height that it’s used as a measurement of standard-of-living.

Visiting the Mutter Museum's website says that all the skulls have been adopted through 2014. Yay for the skulls, but boo for anyone who still had their heart set on adopting. — Asked by tevokkia

I see that :( From a few correspondences that my friend had with the organizer of this fundraiser, I gather that they have a very limited number of highly-skilled restorationists, so while the overall cost of all of the repairs/reinforcements of all of the skulls in this collection is probably going to take 3-5x the amount they raised this year, and that’s before the ongoing maintenance costs to make sure they don’t fall apart in the future, their staff can only put in so many hours.

But! That means that this is going to be a multi-year program, and it looks like next year might have some tiered benefits. But nothing’s set in stone yet…all I know is that this is for sure going on at least through 2015, and they’re probably going to kick off the fundraiser on Halloween next year, so mark your calendars :D