Is Magma considered the Earths blood?

No, this is not a good analogy. Blood has a purpose for existence. It carries oxygen and nutrients from one part of a body to another. Magma has no purpose, it is just melted rock that exists in particularly hot places in Earth's mantle. read more

Blood takes up about 5% of a body, magma takes up a vanishingly small percentage of the Earth. Blood distributes oxygen, hormones and transports waste, magma is not involved in any metabolism. Blood is produced by a body for a specific purpose, magma comes into existence by purposeless partial melting of heated rocks. read more

Magma is a kneaded mixture of various minerals in liquid form under the earths crust. Till the time it remains under the earth's crust it is known as magma and when it errup on the surface of earth then it is known as Lava . read more

Magma is primarily a very hot liquid, which is called a 'melt.' It is formed from the melting of rocks in the earth's lithosphere, which is the outermost shell of the earth made of the earth's crust and upper part of the mantle, and the asthenosphere, which is the layer below the lithosphere. read more