Maria Popova of the always neat Brain Pickings has a great review of The Art of Medicine: Over 2,000 Years of Images and Imagination by medical historian Julie Anderson and science writers Emm Barnes and Emma Shackleton.

The iconic image above is the classic 1926 illustration by Fritz Kahn titled Der Mensch als Industriepalast / Man as Industrial Palace

Dan Beckemeyer added needle felted muscles and blood vessels to anatomical diagrams. It’s like the drawings are coming to life.

Link -via Colossal

Fireflies and jellyfish glow, but humans? Believe it. The phenomenon is a natural byproduct of the metabolic process, and scientists have long been aware of the presence of bioluminescence in most living creatures. But it wasn’t until 2009, when a team of Japanese researchers developed a camera 1000 times more sensitive than the human eye, that human bioluminescence was captured on film. The light show apparently works on a 24-hour cycle — brightest in the late afternoon and on the cheeks, forehead and neck. Next time someone tells you “you’re glowing,” you can take it literally.

That’s just one of 11 insane features that you probably haven’t thought about in the human body. Bone up on all of them at mental_floss. Link

(Unrelated image credit: Flickr user Scorpions and Centaurs)

It may not be anatomically correct, but you have to admit it’s perfectly descriptive! This illustration is from UK artist Jim Lockey. Link -via Nag on the Lake

If you have a baby and want to know how successful he will be in certain sports or how popular he will be with the ladies, it turns out, you can actually gauge these pretty well even before he starts learning how to throw a baseball. Learn how and read more about weird physical indicators over on Cracked.

Link

Figure 1. Battle between Lapiths and Centaurs (Centauromachy) at the wedding of Perithoos with Hippodameia (Vase 5th century b. Chr.)

by Univ.-Prof. Dr. Dr. H.C. Reinhard V. Putz
Institute of Anatomy, Ludwig Maximilian University Munich/Germany

This study concerns itself with the systematics of Centaurean anatomical conditions. These are bound to be highly peculiar, combining, as they do, an animal trunk (the equine component) with a human trunk sans legs (the human component). (See Figure 8.)

A staple of Greek mythology, Centaurs have made many appearances throughout the centuries and even in our own time. They are represented by numerous sculptures and images in museums. True, when speaking of Centaurs, we have to rely on two- and three-dimensional models—here as many other instances in biology—because there has not yet been a sighting of a live specimen. However, the majority of extant graphic documents show a degree of verisimilitude and accuracy that makes them appear quite trustworthy, at least as regards the outward appearance of those beings.

Figure 2. Hypothetical skeleton of Centaurs.

Historical Background
As we know from the ancient Greeks, the Centaurs are the offspring of the ill-fated relationship of Ixion, the king of the Thessalian Lapithes, and a cloud with the features of Hera, the wife of Zeus. At the wedding of Perithoos, king of the Lapithes, the drunken Centaurs sought to ravish the Lapithes’ wives. In the ensuing battle (the Centauromachy), they were driven from Thessalia to the Peloponnese. Quite understandably, Centaurs and Lapithes became mortal enemies on that day.

Materials
Since neither fossils nor living specimens of Centaurs have hitherto been discovered, the present study must be founded upon artistic renderings of its subject matter. These are abundant; collectively, they offer us a wealth of data. The most ancient depictions of Centaurs may be found on Grecian vases (see Figure 1). Greece and Rome have provided us with impressive sculptures. Medieval sources, on the other hand, are primarily scriptorial. Artistic renderings of Centaurs soared at the onset of the Modern period. Judging by the number of sculptures extant, Centaurs must have enjoyed remarkable popularity in the Renaissance. They have also inspired sculptors of more recent times.

Methods
This is a foundational survey of the Centaurean body and its organs. We present no statistical analyses. The sizes of sets of specimens are widely heterogeneous and can by no means be considered evenly distributed as regards their characteristics.

Nomenclature
The classic Centaur consists of two body parts, which meet at a right angle. The vertical or anterior part shows all the characteristics of the species Homo. For simplicity’s sake, however, we will simply refer to it as Anterior (A). The horizontal part is the posterior one. In classic Centaurs, this quite obviously belongs to the species Equus. We will simply call it Posterior (P). For the purpose of the present study’s phylogenetic considerations, and in order to improve legibility, species-related epithets will be attached to these terms. When describing and discussing classic Centaurs, therefore, the anterior part of the body will be referred to as Human Anterior (HA); the posterior part, as Equine Posterior (EP).

(Image credit: Flickr user Terence Faircloth)

Two Parts
The anterior (HA) of the classic Centaur consists of a human element constituted by a head, a neck, a thorax with upper extremities, and an abdomen. The presence of a pelvis cannot be established with certainty. At any rate, the outward appearance indubitably and undeniably shows that HA—down to the umbilical region—possesses that human plasticity that is described in any modern anatomical atlas (e.g. Putz and Pabst, 2005). In contrast, EP consists of a near-complete horse’s trunk with a tail and four extremities. Again, the plasticity of the trunk allows us to accept as standard the equine anatomy that is exhaustively documented in the relevant literature (e.g. König and Liebich, 1999).

Two Sexes
Owing to the far larger number of samples of male Centaurs, the present study will not be concerned with the anatomy of females, with the exception of a brief discussion of the external genital organs. The intensive analysis of female centaurs is a task we leave for future researchers.

Two Structural Principles
We take into account two different structural principles in the hypothetical anatomy of classic Centaurs. On the one hand, the Centaurean body contains simple systems, such as the locomotor and the nervous systems; on the other hand, there exist duplex systems, such as the digestive, respiratory, circulatory, and urogenital apparatuses (see Table 1).

Simple Systems: The Skeletal Locomotor Apparatus
The most problematic region, and the main focus of attention, is the junction of the two body components. It appears that EP provides a fully developed thorax complete with thoracic spine as the basis from which HA emerges. However, there is no way of ascertaining whether there also exists an equine cervical vertebra. As regards the scapula, we may safely assume that it serves a double purpose. Firstly, its functional orientation is toward the anterior extremity of EP. This suggests that the scapula may be suspended in a complex web of muscular loops and that it has to possess a certain dynamic mobility. Second, the scapula’s spatial proximity to the pelvic region of HA assigns to it the task of supporting the weight of HA, which demands a relatively a higher stability.

Concerning the caudal end of HA, the humanoid systematic of the pelvic skeleton suggests a somewhat stronger connection of the pelvis with the spine. This peculiarity may be explained by the specific structure of the syndesmotic junction, which is a characteristic e.g. of the locomotor segments of the lumbar column and which is present in the interosseous talocalcanear ligament. There is also the possibility of an ilioscapular joint. However, a comparison of various Centaurs in various positions suggests—at least in the case of classic Centaurs—the presence of synosteosis and, therefore, of an ilioscapular bone (see Figure 2).

(Image credit: Flickr user Ed Schipul)

If we assume such a junctional bone, we have to conclude that the vertebral column of HA contains an indeterminable number of sacral segments above the fifth lumbar vertebra. This has to be the case because usually, in primates, os coxae is immediately connected segmentally with os sacrum. The connecting equine vertebra—depending on the length of the human portion of the sacral section—is either one of the lower cervical vertebrae or the uppermost thoracic vertebra. Apart from the very peculiar structure of this humano-sacro-equo-thoracic transition, the skeletal elements of both components seem to show the correct features appropriate to the respective species.

Simple Systems: The Muscular Locomotor Apparatus
The Centaurean corporal plasticity not only allows us to comprehend the structure of the skeletal elements; it also gives us an understanding of the muscular relief. Again, it seems certain that both HA and EP present themselves in a manner appropriate to the respective species as described in the relevant textbooks. Of course, certain problems arise in the transitional area. The caudal ventral muscles of HA emerge from both rectus muscles as well as from the lateral ventral muscles. The rectus muscles in particular are often visible in the shape of two pronouncedly modeled bulges beneath the skin. On the part of EP, the anterior termination of the musculature of the trunk is a large, symmetrical muscle shield, which is quite evidently constituted by the two major pectoral muscles. It cannot be ascertained whether there is a sternal muscle located between these muscles, as is commonly the case in the species Equus. At any rate, the Centaurean body seems to have formed a pectoral-abdominal muscle shield that is characterized by a fascinating interplay of differently oriented fibers. Specific developments of this kind are by no means uncommon, as is proven memorably by the rich array of variants in mammals (Romer and Parsons, 1978).

Figure 6. Hypothetical central nervous system of Centaurs.

Simple Systems: The Central Nervous System

The arrangement of the central nervous system in classic Centaurs is comparably easy to interpret. Obviously, the head contains a cerebrum, connected to the medulla, which in turn is located in the vertebral canal. Certain intumescences of the medulla at the sites where nerve tracts link to the extremities are common in mammals. In Centaurs, this accounts for the presence of a humano-cervical intumescence as well as of an equo-lumbal intumescence. Since the anterior extremity (forehand) of EP presents itself as properly equine yet fulfilling increased static and dynamic demands owing to the larger mass of HA, which rests upon it, a somewhat extended lumbobrachial intumescence has to be assumed. The course and topography of the segmental nerves seem to be appropriate to the respective species. This rigid metamerism is not interrupted in the transitional area.

Surprisingly, the relative size of the Centaurean cranium is in fact disproportionate. In spite of its significantly increased peripheral distribution area, the brain volume is no larger than human average, or so the shape of the skull seems to suggest. Another question that must remain open is that of the allometric functioning of the cerebellum, which has to coordinate six instead of four extremities. It must be assumed that the proportions of the brain segments strongly diverge from the common human type.

Figure 3. Hypothetical digestive apparatus of Centaurs.

Duplex Systems: The Digestive Tract and the Common Rectum
Since there is no evidence of HA’s digressing from the forms of fully developed Homo sapiens, it has to be assumed that also the Centaurean digestive tract, at least up to the sigmoid colon, is developed in the same manner as in the human body proper. Besides, the iliac crest allows conclusion to the position of the vermiform appendix.

The transportation of food to the equine stomach poses another problem. At this point, we must forego the question of where the connection to the equine stomach branches off from the common esophagus. Owing to a certain lack of space in the area of the posterior mediastinum, we can assume that this embranchment occurs after the common esophagus has passed the human diaphragm, and slightly above the cardia, that is, away from the abdominal portion of HA. This branch of the esophagus passes the equine thorax in a generous arch that stretches to the equine stomach. The further formation of the specifically equine digestive tract appears to follow the textbook pattern. It ends in a common rectum. This is the term employed here for that section of the intestine that is joined by an elongated colon linking from HA.

It must be made quite clear, of course, that the gaster of EP, here called “equine stomach” for convenience’s sake, can by no means be a regular horse’s stomach. It is merely localized in the position of the equine gaster; however, its function  has to be that of a regular human stomach, since the upper gastrointestinal tract, which supplies it with food, is clearly human. There is no hint in the relevant literature that Centaurs subsist on other than human food. The sources indicate, however, that Centaurs were rather fond of Greek wine. Precisely this uncontrolled predilection for alcohol was to play a fateful role in their conflict with the Lapithes (that is, the Centauromachy). Therefore, it is clear that the small intestine of EP follows the functional principle of its human counterpart and thus has to be significantly shorter than the equine small bowel, which is usually as long as 25 meters (80 feet). Likewise, the length of the cecum has to correspond to the usual length of the human cecum, which measures approximately 10 centimeters (4 inches).

Figure 4. Hypothetical respiratory apparatus of Centaurs.

Duplex Systems: The Respiratory Apparatus
As can be deduced from the external appearance, the respiratory apparatus is constructed in a manner similar to the gastrointestinal tract. There seems to exist a common trachea, with a bifurcation occurring at the height of the third or fourth thoracic vertebra of HA. The anterior pipe—”short trachea” for our purposes—corresponds to the human windpipe and ramifies into the various pulmonary bronchi. The primary pulmo (that of HA) is situated correctly in the two pleural cavities. The long trachea penetrates the human diaphragm, presumably in front of the esophagus yet behind the heart, and enters the equine thorax in an elegant curve. It ramifies into the secondary pulmo according to the well-known structural principle of the equine lung.

Further interesting issues are the extension of the pleural cavities, which are indispensable for the mechanics of breathing, and the synchronization of the two diaphragms. The interaction of the two tightly linked respiratory systems indubitably poses a tremendous challenge to the central nervous system.

Duplex Systems: The Circulatory System

Figure 5. Hypothetical cariovascular apparatus of Centaurs.

The structure of the circulatory system is particularly interesting. We could assume the existence of two hearts that sustain circulation in their function as pressure and suction pumps. It would not be entirely illogical, however, to suggest two separate circulatory systems, since the respective blood pressures of Equus and Homo, the original species, are considerably different. However, the two systems may have aligned in the course of phylogenesis.

Yet for simplicity’s sake, let us assume a primary and a secondary heart. The cranial aorta emerges from the primary heart. Since HA does not need common iliac arteries, it has to be taken that the cranial aorta immediately joins the caudal aorta. This happens in the area of the aortic arch that emerges from the secondary heart. The further structuring of the caudal aorta follows the principle explained in the standard texts on veterinary anatomy (e.g. König and Liebich, 1999).

The question for the systematics of the transitional vessels remains entirely open. The subclavian artery presumably follows standard patterns; however, the position and function of the common carotid artery are highly problematic. For the present study, we prefer to assume that no equine carotids have been developed. The question of the existence of an equine vertebral artery is particularly stimulating.

The large body veins present no fundamental systematic problem, since they are generally known to be highly variable in form and position. It would be foundationally important, however, to establish the boundaries between the catchment areas of the human inferior vena cava and the equine superior vena cava, respectively.

Figure 7. Hypothetical urogenital apparatus of Centaurs.

Duplex Systems: The Urogenital Apparatus
The structure of this part of the metabolic system appears unproblematic. Obviously we have to assume two (caudal) kidneys in HA. The long ureters connect these with the common urinary bladder through the retroperitoneum and the posterior mediastinum (or the retroperitoneum) of the equine thorax/abdominal cavity. The caudal kidneys of EP doubtlessly possess ureters, which we will call short ureters. These are linked to the posterior of the urinary bladder at the lateral posterior wall of the minor pelvis. Quite understandably, only a single urethra leads from the urinary bladder to the anterior abdominal wall. The penis is likewise developed according to equine anatomical standards. Somewhat surprisingly, if one considers possible reproductive techniques, even a painstaking scrutiny of the Centaurean body yields evidence of only one pair of reproductive glands.

The Cretan Variety
There seems to exist in Crete a very rare variety of Centaurs that are equipped with one pair of human legs instead of the equine forehand. This species, quite dissimilar to the regular Centaurean form, also possesses a full human genital apparatus, at least in male specimens. (Due to a scarcity of depictions, there may hardly be any statement made regarding the external genitals of female Centaurs, or Centauresses.) Relevant material is exceedingly scarce and sketchy.

Outlook
By way of summary, we may state that Centaurs and related life forms present a fascinating model for the study of foundational aspects of mammalian morphology and phylogenesis. With particular regard to the big number of questions left open by this study, it seems in order to demand—corresponding to the “Decade of the Brain,” or to the “Decade of Degenerative Diseases” recently postulated by WHO—a new direction of research that paves the way to what might be described as the “Century of the Centaur.”

Acknowledgement
The author is very grateful to Mr. Erich Kaiser, M.D., for his historical contribution, as well as to Mr. Horst Ruß for performing the elegant drawings.

References
The Vertebrate Body, A.S. Romer and T. Parsons, W.B. Saunders, Philadelphia, 1978.
Atlas of Human Anatomy, 14th ed., R. Putz and R. Pabst, Elsevier, Munich, 2005.
Anatomie der Haussäugetiere, H.E. König and H.-G. Liebich, Schattauer, Stuttgart and New York, 1999.

Figure 8. Idealised recent Centaur (in parts a portrait of the author).

_____________________

This article is republished with permission from the September-October 2006 issue of the Annals of Improbable Research. You can download or purchase back issues of the magazine, or subscribe to receive future issues. Or get a subscription for someone as a gift!

Visit their website for more research that makes people LAUGH and then THINK.

Link (in Japanese) – Via Who Killed Bambi

Heart (Anatomy) Keychain – $4.95

Are you afraid of giving someone your whole heart this Valentine’s Day?  Give them the Heart – Anatomy Keychain from the NeatoShop instead.  It’s like giving your whole heart, but in miniature and in plastic.  Plus, if they manage to some how break this heart it won’t hurt that much.

Be sure to check out the NeatoShop for more heartfelt gifts.

Pretty creepy, huh? These unidentifiable biological specimens were created with polymer clay and sealed in glass jars by artist Carim Nahaboo. Link -via Boing Boing

It sounds like something the dog says when he’s trying to recall where he buried it! No, it’s today’s Lunchtime Quiz at mental_floss. How much do you remember about the bones of the human body? In this quiz, you’ll be given the names of nine bones, and you match them to the part of the body they are from. I scored 100%! Link

Animals that live underwater as so different they never fail to astound us. Marine invertebrates may flop like jelly when we see them on land, but in their own environment they can be as rigid as they need to be, thanks to the fluid skeletons they formed by compressing water within their organs. Read about how they work and see some gorgeous underwater pictures at Environmental Graffiti. Link -via the Presurfer

(Image credit: Flickr user Neil Barman)

Walyou has the large pic of Mads’ artwork: iPhone 4 Anatomy and Gaming Controllers and Toaster Anatomy

Rene Descartes’ health may have been troubled, but his genius was completely intact. His survival led to an amazing perspective about why we are here, and the truth behind that notion.

Thus the whole of philosophy is like a tree. The roots are metaphysics, the trunk is physics, and the branches emerging from the trunk are all the other sciences, which may be reduced to three principal ones, namely medicine, mechanics and morals. By “morals” I understand the highest and most perfect moral system, which presupposes a complete knowledge of the other sciences and is the ultimate level of wisdom.

Link

From the Upcoming ueue, submitted by lannaxe96.

Tribbles {wiki} appeared in a 1967 episode of Star Trek: TOS and returned in the spin-off series and movies. Romulan Whore posted this diagram of the inside of a tribble, and attributed it to the Star Fleet Reference Manual. Since there are quite a few such manuals, I don’t know who the artist is. Link -via Buzzfeed

Sam Loman created a map of the human body’s systems using the style of a subway map. The different systems are color-coded as both anatomy books and trains maps are. Link -via Laughing Squid

An object or scene in the visual world is projected as a two-dimensional image on the retina of each eye, so what we see can also be treated as flat sheet: the visual field. Every point on this sheet can be pin-pointed by two coordinates, just like a point on a map, or a point on the flat model of V1. The alternating regions of light and dark that make up a geometric hallucination are caused by alternating regions of high and low neural activity in V1 — regions where the neurons are firing very rapidly and regions where they are not firing rapidly.

A closer look at the types of specialized neurons in the V1 field and how they interact with each other explains the geometric patterns.

Bressloff and his colleagues used a generalised version of the equations from the original model to let the system evolve. The result was a model that is not only more accurate in terms of the anatomy of V1, but can also generate geometric patterns in the visual field that the original model was unable to produce. These include lattice tunnels, honeycombs and cobwebs that are better characterised in terms of the orientation of contours within them, than in terms of contrasting regions of light and dark.

That’s about as simple as I can make it in a short blurb; the entire article explains it better. Yes, there is math involved. Link -via Metafilter

Ever think about which veggies look like our insides? This clever ad can help…not that you need to think about food anymore after your Thanksgiving feast.

Link Via Craftzine Image Via International Vegetarian Union

Thread tiny cameras through the singers’ noses and focus on the larynx. Then have them sing sweetly and see what it looks like deep inside. The singers are Juleiaah Boehm, Emma Deans, Alexi Kaye, and Sally Stevens. -via b3ta

If you’ve ever wondered what’s inside Hello Kitty, we now know there’s a Valentine-shaped heart with a little bow as well as lungs that look at you and cute little intestines. Of course. Designer Dr. Romanelli made these for MediCom Toy Incorporated. Link -via Buzzfeed

Scans of the human brain show how neurons fire in different patterns when we are asleep, drugged, experiencing seizures or headaches, and when the brain is damaged. The image on the left is the brain of someone who is asleep. The right shows the brain of a person in a drug-induced sleep. Link -via the Presurfer

See inside Godzilla, Gamera, and a couple of other movie monsters in poster form. If I could only read Japanese to find out where their weak spots are, then I, too, could save the world! Link -via Digg

Upodate: These are from the book An Anatomical Guide to Monsters by Shoji Otomo with illustrations by Shogo Endo, from 1967. More information can be found at Pink Tentacle, including partial translations. -Thanks, algomeysa!

Mammoth 3D Anatomy Model
Hercules Beetle 3D Anatomy Model	Pig 3D Anatomy Model	Cow 3D Anatomy Model

Forget jigsaw puzzles, over at the Neatorama Shop, we've got some really cool (funducational?) 3D Anatomy Models/Puzzles with removable organs. My favorite is of the Woolly Mammoth and the Snail: Link

The shell itself is made from broadened and flattened ribs, fused to parts of the turtle’s backbone (so that unlike in cartoons, you couldn’t pull a turtle out of its shell). The shoulder blades sit underneath this bony case, effectively lying within the turtle’s ribcage. In all other back-boned animals, whose shoulder blades sit outside their ribs (think of your own back for a start). The turtle’s torso muscles are even more bizarrely arranged.

Ed Yong looks at turtle anatomy and how this weird configuration evolved from the basic vertebrate plan. Link

Ever wonder what the internal workings of a gingerbread man would look like? Artist Jason Freeny has you covered, detailing the full anatomy of one of our gingerbread man friends.

Link

No, not a tattoo though undoubtedly it would make an excellent anatomically-minded example that would rival this famous skull face tattoo we had before on Neatorama. The gruesome painting is actually printed paper by Paris-based photographer Laurent Champoussin.

Vanessa Ruiz of Street Anatomy asked Laurent what inspired his art series titled Cardiovascular Paper:

I’ve always been interested by the écorché model. I was inspired by the classical representations of Andréas Vesalius, Charles Estienne or Adrian Van Den Spieghel. My idea was to play with the partial, the uncovered (open/discover) of an essential part of ourselves. I also wanted to work on the propagation, the invasion. My will was to design the model, to file down it like a texture and I hope, somewhere like a poetry.

More at Street Anatomy Blog: Link | Laurent’s website and blog – via Cakehead Loves Evil

This anatomical duvet cover (or is it blanket?) is titled The Hypochondriac (2004) and is the work of Taiyo Onorato and Nico Krebs of TONK. The duo are great photographers, but their website has atrocious navigation – via Who Killed Bambi?