Final answer:
The bicuspid valve, located in the heart, is supported by papillary muscles connected to it by chordae tendineae, which ensure unidirectional blood flow and prevent the backflow of blood.
Step-by-step explanation:
The bicuspid valve, also known as the mitral valve, is a one-way opening between the atrium and the ventricle on the left side of the heart. Its function is to allow blood to flow from the left atrium to the left ventricle while preventing it from flowing backward. The bicuspid valve is supported by papillary muscles that connect to the valve via chordae tendineae. When the ventricle contracts, the increased pressure closes the bicuspid valve, and the chordae tendineae keep the valve from inverting. The contractions of the papillary muscles also play a role in valve function by tightening the chordae tendineae and preventing valve prolapse.