The alveoli of the lungs are surrounded by capillaries. As the blood travels through the capillaries, the red blood cells become oxygenated and give up their load of CO2
through your pulmonary artery and pulmonary vein.
By relaxing the blood vessels, antiangina drugs reduce the heart's work load and increase the amount of oxygenrich blood that reaches the heart.
throught the Superior and Inferior Vena Cave and into the Right Atrium
When blood leaves the lungs through the pulmonary veins, it returns to the heart and enters the left ventricle.
Oxygenated blood enters the left side of the heart (atria) via the pulmonary veins
Oxygen-poor blood enters the heart through the right atrium
De-oxygenated blood is dark red. Oxygenated blood is bright red. Both enter the heart- the former enters the right heart; the latter enters the left heart.
Right atrium
When blood that is rich in oxygen re enters the heart, the blood enters through the pulmonary valve. The pulmonary valve brings the oxygen rich blood to the pulmonary trunk of the pulmonary artery.
Blood returning from the body systemic circulation first enters which chamber of the heart?
The blood enters throught the heart throught the right and left atria. As the heart contracts, blood flows into the ventricles and then out from the ventricles.
Blood returning from systemic circulation enters the heart at the right atrium. Blood from the pulmonary circulation enters the left atrium.