I think it might be hormones not sure.
Feel less pain at the moment but not in the future
right side:
Blood enters the heart through two large veins, the inferior and superior vena cava emptying oxygen-poor blood from the body to the right atrium.
atrium contracts, blood flows from your right atrium into your <em>right ventricle</em> through the open tricuspid valve.
ventricle contracts, blood leaves the heart through the pulmonic valve, into the <em>pulmonary artery</em> and to the lungs where it is oxygenated.
left side:
<em>pulmonary vein</em> empties oxygen-rich blood from the lungs into the <em>left atrium</em>.
contracts, blood flows from your left atrium into your <em>left ventricle </em>
ventricle contracts, blood leaves the heart through the aortic valve, into the<em> aorta </em>and to the body.
veins carry blood to the heart ( deoygenated blood)
Arteries carry blood from heart ( oxygen rich blood)
Capillaries connects them.
