blood vessel-a vessel in which blood circulates. vein, vena, venous blood vessel-a blood vessel that carries blood from the capillaries toward the heart; all veins except the pulmonary vein carry unaerated blood. venous blood system, venation - (zoology) the system of venous blood vessels in an animal. lymph gland, lymph node, node-the source of lymph and lymphocytes. vascular system-the vessels and tissue that carry or circulate fluids such as blood or lymph or sap through the body of an animal or plant. fetal circulation, foetal circulation-the system of blood vessels and structures through which blood moves in a fetus.
Squirrels are dangerous, not necessarily to humans but to their property. Squirrels will chew through and damage the structure of homes and personal property, including electrical wiring, which is a fire hazard.
Lead is particularly dangerous to children because their growing bodies absorb more lead than adults do and their brains and nervous systems are more sensitive to the damaging effects of lead. Babies and young children can also be more highly exposed to lead because they often put their hands and other objects that can have lead from dust or soil on them into their mouths.