Choking occurs when breathing is impeded by a constricted or obstructed throat or windpipe. Coronary bypass surgery involves bypassing constricted arteries with venous grafts. They are elongated with transversely constricted bodies. Additionally the neural spine base is transversely constricted. This further constricted the already tight housing market for black migrants, exacerbating the housing crisis. Injury or death is plausible if the arteries remain constricted for more than 20 seconds. In addition, the vocal tract may often be constricted in the region of the epiglottis. Milk ducts are often constricted, and breast feeding is difficult, but not necessarily impossible. Pinniped skulls have large eye orbits, short snouts and a constricted interorbital region. In practice, when bearing surfaces are pressed together, the fluid outflow is constricted. In addition, CB1 facilitates ghrelin release, normally happening when the stomach is constricted. Place of articulation refers to where the airstream in the mouth is constricted. The riptides become the strongest where the flow is constricted. They tend to be guarded and suspicious and have quite constricted emotional lives. Critics contend that corsets constricted women's bodies and women's lives.