Blood cells and the spleen.
D001773:Blood Cells / Q000502:physiology*; D004912:Erythrocytes / Q000502:physiology; D006098:Granulocytes / Q000502:physiology; D006410:Hematopoiesis; D013154:Spleen / Q000033:anatomy & histology / Q000166:cytology / Q000502:physiology*; D013156:Splenectomy; D013163:Splenomegaly / Q000097:blood