Star Trek: 10 Crazy Facts About Klingons
9. They Have Redundant Internal Organs
The physiology of a Klingon is shockingly unique, and that doesn't just mean the ridges on their heads.
Excluding their foreheads, Klingons look like most bipedal species on Star Trek. They generally have two eyes, two ears and one mouth, all mounted on their face. They have body with, in most cases, with two arms and two legs. From that perspective, and excluding superficial features, they appear to be quite similar to Humans, Romulans and Cardassians.
It's a much different story on the inside, where Klingons have a unique array of internal organs. To be precise, they have essentially the same organs, just more of them. Klingons reputedly have two livers, three lungs and multiple stomachs. They have a heart but it has eight chambers. It's a lot of extra organs shoved into their torsos.
The presumptive reason for all this redundancy is their warrior ways. It all makes them more difficult to kills as their bodies can keep functioning after sustaining major damage. That's a good thing since there are few Klingon doctors, and the ones they do have are pretty terrible.