In contrast with the first Mishna in the perek on daf 42a, the Mishna on today’s daf lists situations where an animal suffers an injury that does not render it a tereifa, i.e. it is not a terminal condition that will lead to the animal’s imminent death. For example, if the animal’s spine was broken or if its liver was entirely removed, the earlier Mishna teaches that the animal is rendered a tereifa; according to the Mishna on today’s daf, if the animal’s spinal column was broken but the spinal cord remained intact, or if its liver was partially removed but an olive’s size remained, the animal remains kosher.
The Mishna on today’s daf offers a list of cases where internal organs are removed entirely, yet the animal remains kosher. This list includes:
- The spleen
- The kidneys
- The lower jaw
- The womb
All of which are not considered essential to the animal’s continued existence.
The spleen is an organ that is connected with the circulatory system of the blood, as it creates white blood cells and breaks off dead or injured red blood cells. It also creates anti-bodies and plays a role in the immune system. In animals, the spleen is located near the front of the animal near its stomach, and it is tongue-shaped, thick on one end and tapering off on the other. As we know from modern-day medicine, a spleen is not essential for survival, yet disease or complications from an injury to the spleen can be life-threatening, which is why in such cases it is often removed by means of surgery.
Regarding the lower jaw, it is clear that we must be dealing with a case where the trachea and esophagus remain intact. The Rambam argues that although the animal is not a tereifa and can survive if it is missing its lower jaw, if the upper jaw were to be removed the animal would not be able to survive and the animal would be rendered a tereifa.