Write one specific function each of the following organs in relation

Write one specific function each of the following organs in relation with excretion in human beings :

1. Renal Artery
2. Urethra
3. Glomerulus
4. Tubular part of nephron 

Answer

1. Brings the blood containing nitrogenous waste into the kidney
2. Removal of urine / passing out of urine
3. Filtration of blood
4. Selective reabsorption of useful materials