Muscle Tissue: Muscle tissue consists of muscle cells which are specialised in such a way so that they can contract which allows movement. The heart consists of a large amount of muscle tissue which contracts to provide the force to pump the blood out.
Nerve Tissue: In order to ensure the heart muscle tissues contracts at the right frequency, your heart also contains nerve tissue which consists of nerve cells. Nerve cells are long and thin and can transmit impulses over long distances very quickly. We'll come back to nerve cells later in this unit.
Blood Tissue: A functioning heart obviously contains a large amount of blood tissue - both in the chambers to be pumped, but also in the blood vessels supplying the heart muscle tissue with the oxygen and glucose it needs in order to respire to produce the ATP energy it needs to contract. Blood tissue contains red blood cells which are specialised to absorb, carry and release oxygen. We'll revisit blood later in this unit.