Pulmonary vein
Aorta
Pulmonary artery
Vena cava
It is sub-classified as a rough, or granular ER, and a smooth or agranular ER. The rough Endoplasmic reticulum is lined with ribosomes and modifies and packages proteins that have been produced by the ribosome. In skeletal and cardiac muscle it is known as the sarcoplasmic reticulum.
To find the density of an object, divide the mass by the volume. To find the density of the object in your problem, use a calculator to divide 60.0 by 400.0
