HUMAN BODY SYSTEMS Skeletal Muscular Circulatory Lymphatic Digestive Excretory Endocrine Reproductive Skin Respiratory

The human body contains more than 650 individual muscles anchored to the skeleton, which provide pulling power so that you can move around. These muscles constitute about 40% of your total body weight. MUSCLAR SYSTEM

The muscle's points of attachment to bones or other muscles are designated as origin or insertion. The point of origin is the point of attachment to the bone to which the muscle is anchored. The point of insertion is the point of attachment to the bone the muscle moves.

There are about thirty muscles associated with facial expression (controlling the eyes, face, and mouth). These muscles take their origin from the bones of the facial skeleton and attach to the soft tissues of the facial skin, such as the eyelids, nose, cheeks, and lips. There are seventeen smiling muscles in all. All the muscles of the face are supplied by branches of two main nerves, the right and left facial nerves, which arise from the brain stem. These branches of the facial nerve control the muscle movements of the face.

Several sets of muscles support and propel the torso. The abdominal wall muscles help transfer force between the upper and lower body, and they also protect the delicate internal organs. Their most important function is to support the back. The muscles of the torso extend in several directions. They help maintain posture and aid the spinal muscles when bending, twisting, and other movements.

In the upper arm, the biceps and triceps are arranged to give the forearm power to thrust and bend. The two muscles join at the elbow and allow you to bend and straighten your arm and also rotate your wrist and hand. The forearm muscles transmit power to the wrist, hands, and fingers. A group of flexors and extensors controls the movements of the wrist, acting in conjunction with other muscles of the fingers, thumb, radius, and ulna.

These sets of muscles allow the arm and wrist to bend (flexion) and straighten (extension) Click here for movie

as well as move outward away from the body (abduction) and inward toward the body (adduction). Some of these muscles participate in more than one type of movement. Click here for movie