MUSCULAR SYSTEMS
The 650 muscles in the human body control movement and help to maintain posture, circulate blood and move substances throughout the body. There are three types of muscles: skeletal muscles, cardiac or heart muscles, and smooth (non-striated) muscles. Thousands, or even tens of thousands, of small fibers make up each muscle.
SKELETAL MUSCLES
Skeletal muscles are the only voluntary muscle tissue in the human body and control every action that a person consciously
performs. Most skeletal muscles are attached to two bones across a joint, so the muscle serves to move parts of those bones closer to each other. The basic action of any muscle is contraction. For example, when you think about moving your arm using your biceps muscle, your brain sends a signal down a nerve cell telling your biceps muscle to contract. Just about all body movement, from
walking to nodding your head, is caused by skeletal muscle contraction. Your skeletal muscles function almost continuously to maintain your posture, making one tiny adjustment after another to keep your body upright. Skeletal muscle is
also important for holding your bones in the correct position and prevents your joints from dislocating. Some skeletal muscles in your face are directly attached to your skin. The slightest contraction of one of these muscles changes
your facial expression.
HEART/CARDIAC MUSCLES
The muscle that makes up the heart is called cardiac muscle. It is also known as
the myocardium Your heart is made of cardiac muscle. This type of muscle only exists in your heart. Unlike other types of muscle, cardiac muscle
never gets tired. It works automatically and constantly without ever pausing to rest. Cardiac muscle contracts to squeeze blood out of your heart, and relaxes to fill your heart with blood.
SMOOTH MUSCLES
Smooth muscle is found in the walls of hollow organs like your intestines and stomach. They work automatically without you
being aware of them. Smooth muscles are involved in many 'housekeeping' functions of the body. The muscular walls of your intestines contract to push food through your body.
The 650 muscles in the human body control movement and help to maintain posture, circulate blood and move substances throughout the body. There are three types of muscles: skeletal muscles, cardiac or heart muscles, and smooth (non-striated) muscles. Thousands, or even tens of thousands, of small fibers make up each muscle.
SKELETAL MUSCLES
Skeletal muscles are the only voluntary muscle tissue in the human body and control every action that a person consciously
performs. Most skeletal muscles are attached to two bones across a joint, so the muscle serves to move parts of those bones closer to each other. The basic action of any muscle is contraction. For example, when you think about moving your arm using your biceps muscle, your brain sends a signal down a nerve cell telling your biceps muscle to contract. Just about all body movement, from
walking to nodding your head, is caused by skeletal muscle contraction. Your skeletal muscles function almost continuously to maintain your posture, making one tiny adjustment after another to keep your body upright. Skeletal muscle is
also important for holding your bones in the correct position and prevents your joints from dislocating. Some skeletal muscles in your face are directly attached to your skin. The slightest contraction of one of these muscles changes
your facial expression.
HEART/CARDIAC MUSCLES
The muscle that makes up the heart is called cardiac muscle. It is also known as
the myocardium Your heart is made of cardiac muscle. This type of muscle only exists in your heart. Unlike other types of muscle, cardiac muscle
never gets tired. It works automatically and constantly without ever pausing to rest. Cardiac muscle contracts to squeeze blood out of your heart, and relaxes to fill your heart with blood.
SMOOTH MUSCLES
Smooth muscle is found in the walls of hollow organs like your intestines and stomach. They work automatically without you
being aware of them. Smooth muscles are involved in many 'housekeeping' functions of the body. The muscular walls of your intestines contract to push food through your body.