When you apply the brakes, brake fluid is forced under pressure into the wheel cylinder, which in turn pushes the brake shoes into contact with the machined surface on the inside of the drum. When the pressure is released, return springs pull the shoes back to their rest position.
Normally, protein is not removed when the kidneys filter waste from the blood. However, when the kidneys are damaged, protein leaks through the damaged filters and is removed from the body in the urine, along with the waste products.
1 When the arteries become damaged, the nephrons do not receive the essential oxygen and nutrients. Also, the kidneys lose their ability to filter blood and regulate the fluid, hormones, acids and salts in the body.  Damaged kidneys fail to regulate blood pressure.