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.
A nephron (from Greek Î½ÎµÏÏÏÏ (nephros) meaning kidney) is the basic structural and functional unit of the kidney. Its chief function is to regulate the concentration of water and soluble substances like sodium salts by filtering the blood, reabsorbing what is needed and excreting the rest as urine.