IGNIS | Page 9

Visceral Muscles Visceral, or smooth muscle, is found on the inside of organs such as your blood vessels, stomach and intestines. Visceral muscles contract to move substances through the organ – such as food, waste and blood. It is the weakest type of muscle tissue, and it is controlled by the unconscious part of your brain – you can't control what it does just by thinking about it! This muscle type is often referred to as 'smooth' as it appears smooth when looked at with a microscope, which is very different to the banded appearance of skeletal and cardiac muscle. Cardiac Muscle Cardiac muscle is also striated, like skeletal muscle – they have dark and light stripes when looked at under a microscope. This tells us that the muscle is extremely strong (like skeletal muscles), unlike the visceral muscles in our organs. Cardiac muscle is found exclusively in the heart and its job is to pump blood throughout our whole body. Again, these muscles are involuntary – we cannot control them just by thinking about it. Although there are hormones in your body and signals from your brain that tell your cardiac muscle to change the rate at which it is contracting, your cardiac muscle tells itself when to contract. You have a 'pacemaker' in your heart, which tells the other cardiac muscles when to contract. This pacemaker is also made of cardiac muscle tissue. Because the muscle tissue can tell itself to contract, it is considered to be 'autorhythmic'. IGNIS 9