Posts tagged spine

View of a Skull III.
There’s so much space in there. Use it.
Leonardo da Vinci, 1489.

View of a Skull III.

There’s so much space in there. Use it.

Leonardo da Vinci, 1489.

Exencephaly, Pseudocephaly, and Anencephaly

In exencephaly, the brain is formed without the brain casing - the cranium. It is generally missing the forebrain (the prefrontal lobe), but is otherwise mostly formed. Despite this, the spinal cord is rarely formed with the brain, as there is a disconnect between the telencephalon and the hindbrain during very early development, and only the midbrain is formed.

In pseudoencephaly (a term rarely used in medicine nowadays), the midbrain and spinal cord are formed, but the forebrain is not.

In anencephaly, the most common of the three conditions, the brain and spinal cord are only tiny specs of what they should be. Curiously, despite them being a literal extension of the brain, the eyeballs sometimes fully form, though with no receptors to process the information they receive, even if the fetus were to survive, they would not see anything.

Human Monstrosities, Part IV. Barton Cooke Hirst and George A. Piersol, 1893.

Someone with more knowledge in terms of neuroscience should correct me but I think a foot fetish would have more to do with classical conditioning (i.e. nurture) rather than synapses for the feet/genitals (nature), and I don't think it's possible for them to physically overlap. If anything, they can fire at the same time in response to sexual arousal/stimuli but only after the two are initially experience together at some point. But this is just me speculating too. — Asked by systema-naturae

*shrug* Can’t say I know, myself. I do know that the two regions are right next to each other, given that the roots of the L5 and S2 vertebrae are heavily involved in spreading the thighs (as well as the mechanoreceptors of that area) as well as all actions of the feet. The L4 roots are implicated in many similar actions, as well.

The thing is, we don’t have a concrete answer to what nerves go *exactly* where in the brain, but we do know that it varies between individuals, and that the two regions can, technically, overlap. While nurture may have more of an influence over fetishes in general, erogenous zones seem to be more influenced by nature…though, of course, we don’t know how the people who were tested in adulthood actually appeared as children. Nurture may well have played a role in the way their adult brain became wired to receive signals.

Regardless, there are multiple types of foot fetishists - some being visual (they want to see feet), some being manually tactile (they want to feel feet while seeing them), and some being pedally tactile (they want their own feet touched). Most are a combination of the three, and the reasons for the development of said fetish surely vary wildly from person to person.

Ankylosing spondylitis in the wrists, forearms, and spinal column

Note the fused wrist bones in the arms, and the abnormal protuberances, fusions, and cavities in the spine.

Ankylosing spondylitis (also known as Bechterew’s disease) is an inflammatory spondyloarthropathy (arthritis affecting the spinal column), and its name comes from the Greek “ankylos-”, meaning “crooked”. Spondylitis can be broken down into “spondyl-” and “-itis”, which mean “spine” and “inflammation”, respectively.

Simply put, it’s a fusion of the joints in the axial skeleton (the spinal column, ribcage, and cervical collar), but there’s little else that’s simple about this condition. While it’s known to have a strong genetic predisposition and heritability, the exact triggers that begin the process of syndesmophytosis (literally "the process of abnormal binding together") which fuse bones together is not known.

While many of the genetic and immune factors in AS similar to those in rheumatoid arthritis, ankylosing spondylopathy has been differentiated from other RA conditions as early as the second century CE, by Galen. Because of its effect on the spinal column, AS has long been known as "bamboo spine".

Unfortunately, despite many treatments and therapies being available to counteract the effects of this autoimmune condition on the bones and organs, there is no cure.

Observations on the hip joint: to which are added … other similar complaints. Edward Ford, 1810.

Brown-throated sloth - Bradypus variegatus
The brown-throated sloth is one of the three-toed sloths, and lives in the neotropical regions of South America. Though the species as a whole eats a wide variety of leaves, each individual sloth tends to specialize in one to three species, and preferentially eats from those particular trees. 
As sloth babies begin to eat leaf particles from their mother’s fur as early as the fourth day of life, they tend to develop the same leaf preferences as her.
That said, sloths aren’t so picky that they won’t eat any other leaves. You may like pizza a whole lot, but would you really JUST eat pizza your whole life? Sloths tend to slow their eating habits significantly when they’re allowed to eat only the species they appeared to be most preferential of initially. 
Brehm’s Tierleben: Allgemeine Kunde des Tierreichs. Prof. Otto zur Strassen, 1912.

Brown-throated sloth - Bradypus variegatus

The brown-throated sloth is one of the three-toed sloths, and lives in the neotropical regions of South America. Though the species as a whole eats a wide variety of leaves, each individual sloth tends to specialize in one to three species, and preferentially eats from those particular trees. 

As sloth babies begin to eat leaf particles from their mother’s fur as early as the fourth day of life, they tend to develop the same leaf preferences as her.

That said, sloths aren’t so picky that they won’t eat any other leaves. You may like pizza a whole lot, but would you really JUST eat pizza your whole life? Sloths tend to slow their eating habits significantly when they’re allowed to eat only the species they appeared to be most preferential of initially.

Brehm’s Tierleben: Allgemeine Kunde des Tierreichs. Prof. Otto zur Strassen, 1912.

Plaster model of executed Chinese pirate

The neck stump of this executed Yangzee River pirate is surprisingly accurate for what was probably a sideshow prop. The cervical spine, blood vessels, muscles, trachea, and esophagus are all visible.

The muscular nature of the esophagus is highly visible here. You can also see the hardness of the trachea.

The donation of this model to the Science Museum London came with little accompanying information, but it is known that it was produced in England, between 1910 and 1922. The braid is real human hair, and the plaster and finish is of a high quality. Given its “blood-splattered” carrying case, it was most likely a prop in a traveling sideshow.

Images via Science Museum London.

Extreme case of kyphotic lordosis.
Kyphosis: Greek kyphos, ”a hump” - the over-curvature of the thoracic vertebrae in the upper back.
Lordosis: Greek lordos, ”bent backwards” - the inward curvature of a portion of the lumbar and cervical vertebral column. All spines should be lordotic to an extent, but an excessive inward curvature (often caused by anterior pelvic tilt) can cause many orthopedic problems.
Orthopadische Chirurgie. Dr. August Schreiber, 1888.

Extreme case of kyphotic lordosis.

Kyphosis: Greek kyphos, ”a hump” - the over-curvature of the thoracic vertebrae in the upper back.

Lordosis: Greek lordos, ”bent backwards” - the inward curvature of a portion of the lumbar and cervical vertebral column. All spines should be lordotic to an extent, but an excessive inward curvature (often caused by anterior pelvic tilt) can cause many orthopedic problems.

Orthopadische Chirurgie. Dr. August Schreiber, 1888.

Position of the spinal cord in the vertebral canal
The spinal cord proper does not extend the entire length of the vertebral canal. It ends between the first and second lumbar vertebra (two vertebra below the last set of ribs - just below the middle of the back), and a bundle of nerves that extend from it, called the cauda equina (“horse’s tail”), extends the rest of the way down the back, and into the sacrum.
In adults, the spinal cord is usually between 17-18 inches long (43-45 cm).Atlas of Applied (Topographical) Anatomy for Students and Practitioners. Dr. Karl von Bardeleben and Dr. Heinrich Haeckel, 1906.

Position of the spinal cord in the vertebral canal

The spinal cord proper does not extend the entire length of the vertebral canal. It ends between the first and second lumbar vertebra (two vertebra below the last set of ribs - just below the middle of the back), and a bundle of nerves that extend from it, called the cauda equina (“horse’s tail”), extends the rest of the way down the back, and into the sacrum.

In adults, the spinal cord is usually between 17-18 inches long (43-45 cm).

Atlas of Applied (Topographical) Anatomy for Students and Practitioners. Dr. Karl von Bardeleben and Dr. Heinrich Haeckel, 1906.

Corrective orthopedic apparatuses for antero-posterior curvature of the spine (Pott’s disease)

From the Charles Lentz & Sons Illustrated Catalog of Surgical Instruments. 1915.

Tuberculous spondylitis - Historically known as “Pott’s Disease”

Pott (or Pott’s) disease was named after Percivall Pott, who wrote several lectures on the nature and treatment of this condition.

The name “tuberculous spondylitis" comes from the disease tuberculosis, and the Greek "spondylos”, meaning spine, and “-itis”, meaning swelling. This is actually a form of chronic osteomyelitis, generally found in the lower thoracic or upper lumbar spine of adults. It’s also one of the oldest chronic conditions for which we have archaeological evidence.

Before tuberculosis had effective treatment modalities, this was one of the most common bone afflictions in adults. There were often internal abscesses that the infection drained into, which, while generally not the primary concern, could rupture and cause peritonitis or generalized infection of the thoracic cavity.

As the condition advanced, the degeneration of the bone often caused spinal cord compression and so-called “Pott’s paralysis" - a form of paraplegia that was actually reversible if the pressure was taken off the spinal cord soon after it started. This was usually done by stiff metal or (later) plastic braces or medical corsets. Once the infection advanced to the point that paralysis was caused, it often caused a complete collapse of the affected vertebrae, and could result in thoracic kyphosis, or “hunchback”.

The images above show a mummified priest of Ammon, from the XXIst dynasty (1000 BCE) of Egypt, with the characteristic lateral protrusion of the spine (left image) that hasn’t yet advanced to a collapse of the spinal discs. There is also a large sac in the abdomen (right image) that was soft when mummification occurred, and which would have been the abscess where the infection drained. There was evidence that the priest lived for over a decade with this condition, and it was probably not what killed him in the end.

Studies in the Paleopathology of Egypt. Sir Marc Armand Ruffer, 1921.

Hero or Armored Shrew (Scutisorex somireni)
This curious creature is very cool, and not nearly well-known enough! Its unique characteristics make it almost as fascinating as the tuatara, but I have seen so very few articles or papers published regarding the species - though the fact that it only lives in central Africa in the deep jungle, in a land of rebel fighters and landmines, probably doesn’t make it very conducive to making researchers desire to go out there and find out more about them.
From what we already know, the armored shrew is unique among mammals, as it has an incredibly strong interlocking spinal column. Early vertebrates had a spine that was interlocking, and today the trait is carried on in many reptiles, amphibians, and the gar fish. However, mammals lost the interlocking spine when they no longer had to carry a disproportionate amount of weight in their thorax and abdomen, and the armored shrew is a callback to the days when we were first differentiating from lizards. From what we know about mole and shrew evolution, it’s presumed that the interlocking spine re-emerged in this species, after millenia of having “normal”, non-interlocking bones for the spinal column.
Thanks to their incredibly strong spine, they are able to withstand incredible weights compared to other similarly-sized mammals. A paper written in 1917 regarding the strength of the interlocking spine noted that "the column can withstand the weight of a 160 lb human without harm". I really have to wonder about how they found that out - a 160 lb human is different than 160 lbs of pressure, due to weight distribution. I have to assume there was, at least at some point, a researcher literally standing on top of their shrew.
The Congo Expedition of the American Museum of Natural History. Published Aug 1, 1919.
[p.s. Thanks to octoberwaffle for bringing this slice of awesome to my attention - it’s been a long time since I was completely clueless about the existence of such a cool creature!]

Hero or Armored Shrew (Scutisorex somireni)

This curious creature is very cool, and not nearly well-known enough! Its unique characteristics make it almost as fascinating as the tuatara, but I have seen so very few articles or papers published regarding the species - though the fact that it only lives in central Africa in the deep jungle, in a land of rebel fighters and landmines, probably doesn’t make it very conducive to making researchers desire to go out there and find out more about them.

From what we already know, the armored shrew is unique among mammals, as it has an incredibly strong interlocking spinal column. Early vertebrates had a spine that was interlocking, and today the trait is carried on in many reptiles, amphibians, and the gar fish. However, mammals lost the interlocking spine when they no longer had to carry a disproportionate amount of weight in their thorax and abdomen, and the armored shrew is a callback to the days when we were first differentiating from lizards. From what we know about mole and shrew evolution, it’s presumed that the interlocking spine re-emerged in this species, after millenia of having “normal”, non-interlocking bones for the spinal column.

Thanks to their incredibly strong spine, they are able to withstand incredible weights compared to other similarly-sized mammals. A paper written in 1917 regarding the strength of the interlocking spine noted that "the column can withstand the weight of a 160 lb human without harm". I really have to wonder about how they found that out - a 160 lb human is different than 160 lbs of pressure, due to weight distribution. I have to assume there was, at least at some point, a researcher literally standing on top of their shrew.

The Congo Expedition of the American Museum of Natural History. Published Aug 1, 1919.

[p.s. Thanks to octoberwaffle for bringing this slice of awesome to my attention - it’s been a long time since I was completely clueless about the existence of such a cool creature!]

Thorax and shoulder girdle
The shoulder girdle is also known as the pectoral girdle. It consists of the clavicle and scapula, and connects the upper limbs of the body to the axial skeleton (the parts that aren’t in the chest or abdomen).
Unlike the pelvic girdle, the pectoral girdle in humans is almost completely non-weight-bearing, and fairly fragile - anyone who has landed hard on their arms (which have very strong bones), but broken their clavicle (with its weak structure), can tell you this in graphic detail.
Gray’s Anatomy. Henry Gray et al, 1911.

Thorax and shoulder girdle

The shoulder girdle is also known as the pectoral girdle. It consists of the clavicle and scapula, and connects the upper limbs of the body to the axial skeleton (the parts that aren’t in the chest or abdomen).

Unlike the pelvic girdle, the pectoral girdle in humans is almost completely non-weight-bearing, and fairly fragile - anyone who has landed hard on their arms (which have very strong bones), but broken their clavicle (with its weak structure), can tell you this in graphic detail.

Gray’s Anatomy. Henry Gray et al, 1911.

Internal View of Lumbar Region
Thanks to the thick, protective mesentery and sheer mass of the intestines (not to mention the consequences if they’re damaged), many surgeries of the pelvic and lumbar organs are performed by opening the back, instead of the abdomen.
You can clearly see both the ascending and descending colon and the kidneys in this dissection.
Anatomy, Descriptive and Surgical. Henry Gray, 1911.

Internal View of Lumbar Region

Thanks to the thick, protective mesentery and sheer mass of the intestines (not to mention the consequences if they’re damaged), many surgeries of the pelvic and lumbar organs are performed by opening the back, instead of the abdomen.

You can clearly see both the ascending and descending colon and the kidneys in this dissection.

Anatomy, Descriptive and Surgical. Henry Gray, 1911.

Anatomy of the coccyx and sacrum
In reference to this question, here is the anatomy of the coccyx and sacrum. As can be seen, the sacral portion of the spinal column is still significantly important, in terms of both structural importance and nervous integration/protection. However, the coccygeal spine does little more than anchor two pelvic muscle pairs, and a few ligaments.
In terms of “having a tail”, the closest humans tend to come to that is being born with a tiny, flesh-covered tail (when the coccyx is malformed), which is almost always removed straight after birth, or being born with spina bifida occulta, which can often present with a birthmark over the site of the malformed vertebrae, which has a tendency to grow hair. This hair has occasionally grown long enough to warrant a person inclusion in a "freak show" as a "tailed man/woman" in the recent past.

Anatomy of the coccyx and sacrum

In reference to this question, here is the anatomy of the coccyx and sacrum. As can be seen, the sacral portion of the spinal column is still significantly important, in terms of both structural importance and nervous integration/protection. However, the coccygeal spine does little more than anchor two pelvic muscle pairs, and a few ligaments.

In terms of “having a tail”, the closest humans tend to come to that is being born with a tiny, flesh-covered tail (when the coccyx is malformed), which is almost always removed straight after birth, or being born with spina bifida occulta, which can often present with a birthmark over the site of the malformed vertebrae, which has a tendency to grow hair. This hair has occasionally grown long enough to warrant a person inclusion in a "freak show" as a "tailed man/woman" in the recent past.

mythologyofblue:


Lewis Sayre and his suspension device for the treatment of scoliosis (1877)

(gravellyrun)

mythologyofblue:

Lewis Sayre and his suspension device for the treatment of scoliosis (1877)

(gravellyrun)