How does blood carry nutrients and oxygen (from the small intestine and lungs) to all the parts of our body ?

Blood vessels help in the transportation of nutrients to all parts of the body. After the absorption of the digested food (nutrients) through the wall of intestines, the veins carry digested food and nutrients like glucose from the small intestines via liver to the heart. From heart, the nutrients are distributed to all parts of the body through arteries.

The blood carries oxygen from lungs to all parts of the body by the help of red blood cells (RBCs). They contain a red pigment called haemoglobin, which transports oxygen to all cells of the body by combining with oxygen from lungs to form a compound called oxyhaemoglobin. The mature erythrocytes do not have a nucleus.