<unk>  is a term used to describe a<unk>  that is<unk>  in the body.  It is used to differentiate<unk> s from<unk> s which are close to the surface, also known as superficial<unk> s.<unk> s are almost always beside an artery with the same name (e.g. the femoral<unk>  is beside the femoral artery).  Collectively, they carry the vast majority of the blood.  Occlusion of a<unk>  can be life threatening and is most often caused by thrombosis.  Occlusion of a<unk>  by thrombosis is called<unk>  thrombosis.
Deep vein
Peripheral vein
Artery
Arteriole
Lymph vessel
Cardiac veins
Bleb 
Femoral vein