Acid-fast rods present in sputum typically indicates a mycobacterial infection. Mycobacteria is a type of germ, and it can manifest in different diseases, the most common is Tuberculosis. Acid-fast is namely due to the bacteria's stain retention to the staining procedure after an acid wash.
Blood flows from the right atrium into the right ventricle through the open tricuspid valve, and from the left atrium into the left ventricle through the open mitral valve.
