'When the heart's atria contract, blood flows from the right atrium into the right this'
ventricle
THE CIRCULATORY SYSTEM: When the hearts atria contract, blood flows from the right atrium into the right this
When the heart's atria contract, blood flows from the right atrium into the right this
When the heart's atria contract, blood flows from the right atrium into the right this
THE CIRCULATORY SYSTEM
ventricle
THE CIRCULATORY SYSTEM