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.

Angeiographie

Vascularization of the organs and muscles. The viscera requires an amazing amount of oxygenated blood to do its job properly, which is one of the many reasons you don’t want to get shot in the gut.

Note the inclusion of the veins that go from the intestines to the liver in the top right quadrant of this plate (the image with the blue vessels) - the hepatic portal vein is not a “true” vein, in that it does not take deoxygenated blood back to the heart and lungs, but it takes nutrient-rich blood from the GI tract into the capillary beds of the liver for processing. 

Anatomie Methodique, ou, Organographie Humaine. Jean-Baptiste Sarlandière, 1829.

Sagittal Cross-Section of Lower Male Trunk

If you look up near the top of the illustration, you can see the left common iliac vein. The common iliac vein consists of both the internal and external iliac veins, which consist of the small veins and capillaries that connect to the intestines. This is the blood in your body that supplies you with nutrients - the acids and enzymes in the human digestive tract break down food into molecules small enough to pass through the wall of the intestine. When blood flows down to the lower abdomen, it drops off oxygen where it’s needed, and picks up the broken-down nutrients, before flowing to the organs where the nutrients will be processed, through the inferior vena cava. [De-oxygenated blood returns to the heart via the superior vena cava, not inferior.]

Applied Surgical Anatomy, Regionally Presented, for the use of students and practitioners. George Woolsey, 1902.

1950s photograph of ascaris worms. Also known as “giant intestinal roundworms”. Infestation causes ascariasis. 

Photograph taken at School of Aviation Medicine by Signal Corps. Retrieved from Library of Congress Digitized Archives.

Roundworms in intestine sample.

U.S. National Agricultural Research Center, 1935.

Though one of the most important steps in an autopsy or necropsy, removal and emptying of the gastrointestinal tract is also one of the most unpleasant steps.

I’ve done this for calves who had only been fed milk, which is smelly but tolerable, and for full-grown cows, which is far less stinky and gag-inducing than a human or carnivore. Full-grown cows are actually better than doing calf intestines, so long as they don’t have much protein in their diet that bypasses the rumen. Both cows and calves are better than people, as plant matter is much more tolerable to the nose (and eyes) than the digestive products that come from flesh foods and from the breakdown process in the human tract.

TMI for someone who doesn’t want to do that for a living? Probably. But it’s something that has to get done in the world. It’s a dirty job. Not a bad one, though.

Postmortem Examinations: Methods and Technique. John Caven, 1900.

scientificillustration:

From: ‘Orang-outang, sive homo sylvestris: or, The anatomy of a pygmie compared with that of a monkey, an ape, and a man’ To which is added, A philological essay concerning the pygmies, the cynocephali, the satyrs, and sphinges of the ancients. Wherein it will appear that they are all either apes or monkeys, and not men, as formerly pretended. By Edward Tyson Published 1699

For more images see: BibliOdyssey