How do the respiratory and circulatory depend on each other for gas exchange?

Haemoglobin in the red blood cells which is one of the components of the circulatory medium, the blood, has a great affinity for oxygen hence transports it around the body during circulation. It is the circulatory system that carries both oxygenated and deoxygenated blood around the body, between the lungs and the heart. The circulatory system takes blood with carbon dioxide to the lungs where oxygen that entered into the body through the nostrils will be exchanged with carbon dioxide in the alveoli. Consequently carbon dioxide will go out of the body through the nostrils via the trachea and haemoglobin in the red blood cells in the blood (blood capillaries) will

carry oxygen which is transported around the body.