Can a severed limb that has run away from home be found again?

Friends who have watched "Douluo Dalu" may know this scene:

In order to return the sect's inherited soul bones, Tang San's father Tang Hao cut off his left leg and right arm, and used a high-level ultimate skill called "regeneration of broken limbs" to regenerate gray-white "hands and feet" that were exactly the same as the original ones, with red and white things lingering around them.

Image source: Douluo Continent

Of course, this is a scene that appears in anime. So, in real life, can people and animals regenerate after losing limbs?

A few animals can regenerate limbs after losing a limb, which is called limb regeneration.

However, for humans, regeneration of severed limbs is currently impossible and the only option is to transplant them back, which is called limb replantation.

Which animals can regenerate their limbs so miraculously? Here we introduce to you a small animal that can be said to be quite amazing - the sea slug.

After the head is cut off, the body can grow back

There are some magical creatures in nature that have amazing regenerative abilities, such as geckos breaking off their tails to survive, earthworms breaking off segments, and salamanders breaking off limbs. In addition, Japanese scholars have also discovered a small animal with extremely strong regenerative abilities, which is the sea slug.

Image source: baijiahao.baidu.com

The sea slug has two rabbit-ear-like tentacles on its head, so it is also called sea hare. It belongs to the phylum Mollusca, class Gastropoda, subclass Opisthobranchia, order Opisthobranchia, suborder Nudibranchia, family Aplydae, genus Aplysia.

Japanese researcher Sayako Mito discovered a very strange phenomenon while studying sea slugs: the head of a sea slug was separated from its body, and the separated head could actually swim around without organs such as a heart, and could eat normally just like when the body existed (it seemed that the separation of the head and the body was just an illusion)!

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Normally, the head of an animal will die soon after being separated from its body, but the miraculous thing is that the head of the sea slug is not only alive and well, but after a period of time it also grows a new body and returns to its original appearance. It's simply incredible!

Image source see watermark

Further research on this phenomenon revealed that there is a part on the sea slug's neck that is similar to a fracture plane. The existence of this fracture plane provides conditions for the sea slug to decapitate itself.

But not all sea slugs will decapitate themselves. In this scholar's study, 5 out of 15 sea slugs suffered decapitation!

Why is this?

Mito Hayaka believes that the sea slugs may have self-decapitated because their bodies were parasitized by parasites, and they used the heroic method of cutting off their arms to get rid of their original bodies. However, the results of the study found that there were no parasites in the discarded parts, so the reason why they regenerate after decapitation remains to be explored.

A few hours after being decapitated and discarded, the heads of most sea slugs will begin to eat, and the wounds on the head will heal within a day. After about 7 days, a heart will grow under the head, and after about three weeks, the body will be fully recovered and it will become a complete sea slug again.

The strong regeneration ability of sea slugs is not unique, and is common in some other invertebrates such as starfish, but this phenomenon has disappeared in higher mammals. Higher mammals such as humans cannot regenerate broken limbs. Once a limb is broken, it can only be replanted within an effective time.

Replantation of human limbs

Many people suffer limb separation, such as fingers, forearms, feet or calves, due to various accidents at work or in life.
While patients endure tremendous pain, the biggest problem that needs to be solved is how to rely on doctors to reconnect the severed limbs and restore their original functions in the shortest possible time.

The earliest limb replantation in my country was in 1963. Dr. Chen Zhongwei used the technology of anastomosis of blood vessels and reconstruction of blood circulation to help a patient with completely severed distal forearm to successfully replant the arm, and the patient's function was restored well.

With the advancement of medical technology, limb replantation in my country has reached a relatively high level. Reported cases include replantation of intact limbs remaining from damaged limbs (if there is an intact or partially usable distal end remaining after a limb is damaged, it can be used for in situ or transposed replantation to restore part or most of the function of the damaged limb), replantation of multiple limbs severed at the same time, replantation after limb amputation due to malignant tumors, replantation of avulsed limbs, replantation of high-positioned limbs, and replantation of pediatric limbs.

In short, if the misfortune really happens, please rush to the hospital immediately.

So what steps are generally involved in replantation of a severed limb?

After the patient is anesthetized, the wound is cleaned first, then the bones and joints are fixed, and then the tendons, blood vessels, and nerves are sutured. Finally, the skin is sutured and covered (it sounds simple, but whether it is simple or not, I believe everyone understands).

If an accident unfortunately occurs, is everything fine after completing the limb replantation surgery?

No! There are many things to pay attention to after the limb replantation surgery. If you are not careful, it may cause the limb to necrotize again after the surgery. There are many things to pay attention to after the limb replantation surgery, including ensuring that the patient has enough rest, about 7-10 days of absolute bed rest, and reducing activities as much as possible. This is the basic guarantee.

In addition to normal life care, patients also need to maintain a happy mood and avoid negative emotions such as excessive tension and worry about postoperative effects, which may cause vascular spasms and affect blood supply to the limbs (a good mood is very important).

When a limb is severed due to trauma or surgery, the artery must be anastomosed to ensure normal blood circulation of the severed part, and careful care must be taken after the operation. Therefore, when doing dangerous work, you must respect the rules, respect life, and be careful!

Whether it is the regeneration of severed limbs or the replantation of severed limbs, it is all evolution or development for the purpose of enabling organisms to survive better in nature.

Maybe one day, with the development of technology, humans will be able to regenerate limbs on their own after accidentally losing a limb, just like anime characters. Let’s look forward to it together!

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#Review expert Qu Bo, deputy chief physician of the Department of Neurology, Airport Branch, Peking University Third Hospital. Tadpole stave original work/Reprinted with source editor/Heart and Paper