Answer: Blood to kidney excretory tubes,
- Air tubes to blood
- Blood to air tubes.
The body contains several internal exchange systems. In the kidney, metabolic wastes move from BLOOD to KIDNEY EXCRETORY TUBES. In the lung, oxygen moves from AIR TUBES to BLOOD, while carbon dioxide moves from BLOOD to AIR TUBES.
Explanation: In the kidney, metabolic wastes move from the blood to the kidney excretory tubes via the affarent arteriole into the glomerulus of the bowman's capsule from where there will be ultrafiltration of the wastes from the blood will take place followed by selective reabsorption and tubular secretion inorder for urine to be formed.
In the lungs,oxygen moves from the air tubes which are the bronchial tubes then to the alveoli where gaseous exchange takes place then the oxygen moves to the blood. While carbondioxide moves from the blood to the air tubes from where there is exchange of gases then the carbondioxide is exhaled/expired from the lungs.