What hormone dilates systemic arteries increases cardiac output and increases blood flow to the kidneys causing urinary output?

The hormone you are referring to is atrial natriuretic peptide (ANP). ANP is released by the heart's atria in response to increased blood volume and pressure. It causes dilation of systemic arteries, increases cardiac output, and promotes natriuresis, leading to increased urine production and reduced blood volume. This helps to regulate blood pressure and fluid balance in the body.