Where is the blood going to when it leaves the right side of the heart?

The pathway of a red blood cell from the right atrium and back.

(1) right atrium ->

(2) right AV valve ->

(3) right ventricle ->

(4) pulmonary valve ->

(5) pulmonary trunk ->

(6) pulmonary arteries ->

(7) lungs, for exchange of gases (not shown) ->

(8) pulmonary veins ->

(9) left atrium ->

(10) left AV valve ->

(11) left ventricle ->

(12) aortic valve ->

(13) aorta ->

(14) other systemic vessels ->

(15) inferior and superior venae cavae ->

(16) back to the right atrium

The pathway from 5 to 8 is the pulmonary circuit.

The pathway from 13 to 15 is the systemic circuit.