7. Fixation instead of toast


Dissection of a cadaver takes few hours for a forensic doctor, but it takes months for a med student. At the end of each dissection class, cadavers are covered with cloth. They are uncovered in the next class to continue dissection. This is done repeatedly for months so that we do not miss even the smallest structures of a cadaver. Cadavers have to stay in good condition for months so they are treated with preservatives in preparation for an anatomy lab.

Anatomical terminology for treatment with preservatives is fixation. It means to fix the lively appearance. The preservative that is injected into the cadaver is called the fixative. The main component of fixatives is formalin. Formalin is toxic to humans, so it is diluted before use. It has been in use for hundreds of years and has not caused much problem. If there were any problem, anatomy instructors who come in contact with the fixed cadaver frequently should die earlier than others, but that is not the case.




When old people meet each other, they often say You look young. Sometimes they mean it, but sometimes they say it just to make the other person feel better. When someone tells me that I look young, I say "That is because I am always in touch with fixatives. That is why my body doesn't decay, and that is how I keep the youth in me". If the person laughs, I throw the final joke. When an anatomy instructor dies, the dead instructor should be cremated because the body wouldn't decay after it is buried.

The way to fix a cadaver differs from school to school. My school uses the following method. First, expose the femoral artery in the anterior part of thigh. Pulse can be felt through femoral artery in a living human, which means it is nearby the skin. Therefore, femoral artery can be exposed without dissecting much.

Then, place a needle into the femoral artery and inject the fixative. Arteries and veins are located throughout the entire cadaver and are connected through heart. Thus, fixative that is injected into femoral artery spreads all over the cadaver. While doing so, cut open the femoral vein and withdraw blood from arteries and veins. This allows the fixative to replace blood.

If the fixative doesn't spread out very well, parts of cadaver will decay. All of the cadavers are from donations and it is very unfortunate to see cadavers be improperly dissected. Sometimes, midway through dissection, students find parts of their cadaver rotten. Students can ask for a new cadaver. However, they would have to start again from skinning, so there is a controversy among them. Some say "let's get a new one although it would take some time," some say "let's just go on with the same cadaver, and study based on other groups' cadavers."

One of the reasons why fixative fails to spread out well is because of the poor condition of the vessels of the cadaver. A typical example is atherosclerosis caused by consumption of greasy food and lack of exercise. If atherosclerosis gets worse, an artery can be plucked and ruptured, causing bleeding. If the condition of the vessels is poor, there is trouble in blood circulation when alive and there is trouble in circulating fixative as a cadaver. Eating less greasy food and exercising is not only for me but also for the good of other people.

Another reason behind failure of thorough fixative distribution is due to failure of proper fixation. Just like there are radiological technologist, lab technologist, and physical therapist in hospitals, there is an anatomy technician in a medical school. The technician is in charge of fixation and works hard to maintain related techniques. Whenever a cadaver comes in, the technician puts in enormous effort to fix it, but sometimes it just does not turn out that well.




In the past, alcohol was used as a fixative instead of formalin. This is the same reason why alcohol was injected into insects collected as summer vacation homework. Many anatomy professors enjoy using ethyl alcohol (liquor). They yell out fixation instead of cheers in bars. Their theory is that fixation is the start of anatomy, and anatomy professors themselves should be fixed first. Is this a matter of sacrifice? Nope, it is just a silly excuse to get drunk. Anatomy professors are likely to die early from ethyl alcohol than from formalin. Fixation is the start of anatomy, and a very important process.