One issue is to which President or Congress a particular year's deficit should be attributed. U.S. Congressional terms start on Jan. 1, Presidential terms later in January, and the fiscal year on Oct. 1, so none of them exactly match up.
These nephridia, which are called protonephridia, are branched tubules of ectodermal origin. They are closed at the internal ends by terminal cells, or solenocytes, and open to the exterior by means of excretory pores, or nephridiopores.
The nephron or uriniferous tubule is the functional unit of the kidney. A nephron consists of a twisted tubule closed at one end, open at the other with a network of associated blood vessels.