hematopoiesis is the development of new blood cells. it occurs within the bone marrow

artery vein blood vessel circulatory system body disease human pain heart organ biology vessels cardiovascular lung vascular smooth muscle aorta vasculature embolism arteriole systemic circulation venule pulmonary capillary venous valve flow wall squamous epithelium connective tissue pressure anatomythrombosis deep thrombosis clot symptoms thrombus embolus occlusion coagulation disorder lack exercise adverse reaction chest death lifestyle