You have presented the anatomy of hematopoietic organs very well. We should know these things. If I had seen your post before I submitted my post, I would have tried to present the functions and anatomy of hematopoietic organs like you. You have mentioned here a point of need for an ideal blood donor selection which is hemoglobin. A blood donor should have his hemoglobin level checked. As far as I know the normal hemoglobin level of a healthy person is 12-15g/dl for women and 13-17g/dl for men. Best wishes to you.