The spleen is involved in the production red blood cells to replace the daily, and natural loss of red blood cells. A typical RBC lives 120 days, and with billions in the body, large numbers die daily and are replaced by the spleen. The spleen is also a part of immune system.
For a character to say that it isn't known what the spleen does; is a failure in the whatever research was done.
Ira states that Moses had no children. Moses in fact was married to Zipporah who gave birth to Moses' two sons; Gershom and Eliezer (Exodus 18:2-4).