MEDICAL ENCYCLOPEDIA. 1  Back pain - returning to work. 2  Back pain and sports. 3  Compression fractures of the back. 4  Lifting and bending the right way. 5  Lumbosacral spine x-ray. 6  Returning to sports after a back injury. 7  Spinal fusion. 8  Spinal fusion - slideshow. 9  Vertebroplasty - slideshow.
The mucociliary escalator is one of the major defense mechanisms, which protect the lung, and if the mucociliary escalator fails, it increases the risk that the normal and potentially pathogenic, inhabitants of the nose, throat and the back of the mouth, will descend into the lung, resulting in a potentially life-threatening pneumonia ( Anatomy and Physiology, 2013, p. 139).
Quick Answer. The purpose of the precipillary sphincter is to adjust the flow of blood into the capillaries. These smooth muscles contract and act as a valve to redirect blood to the area where the body needs it most. They encircle each capillary branch at its exit from the arteriole, according to Reference.com.