4. The tonsils (glands)
The tonsils are an accumulation of adenoid tissue located in the epipharynx. They protect us from bacteria and viruses that we breathe in on a daily basis in large quantities. Sometimes, if the tonsils remain inflamed for a long time, they can themselves become a source of infection rather than continue to protect the body. It is on these occasions that doctors usually recommend removing them. The full immunological role of the tonsils remains, however, not entirely understood.
5. Nipples on men
The appearance of nipples is connected with the fact that, right after conception, the Y-chromosome is inactive, and so all embryos begin their development in the same way. It is only during the second month of development that the genes are “turned on.” At this point, the first sex glands in males turn into testes and begin to produce male sex hormones. A significant amount of restructuring consequently takes place. However, the nipples remain in place.
6. The spleen
The spleen was once dubbed “a complete mystery.“ Its functions are still not completely understood. Nevertheless, we do know the following: It produces lymphocytes and antibodies; It gets rid of old red blood cells, the remains of which are sent to the liver; It serves as a ”depot” for blood, which is released when the body copes with large physical loads.