The muscular system is responsible for movement in the human body. This organ system contains up to 650 voluntary skeletal muscles. Muscle can compose up to 30% to 50% of body mass depending on fitness level and other factors. There are different types of muscles. Skeletal muscles are striated having a stripped appearance and are under voluntary control. Smooth muscle performs tasks that are signaled by the nervous system. Cardiac muscles function solely for the heart. The voluntary skeletal muscles are responsive to signals to the brain, which controls movement. These muscles can either contract or in other instances lengthen. The tendons acts as connectors between muscle and the bones. Each muscle has a specific name.
Muscles of the face
- Frontalis- The muscles of the forehead
- Temporalis- The muscle that covers the temporal bone
- Zygomaticus – The muscles of the cheeks
- Orbicularis oculi – The muscles around the eye
- Masseter- The muscles of the jaw
Every facial expression we make requires muscles. Frowning and smiling may seem like simple acts, but nerves and muscles work in coordination. Facial muscle connect to connective tissues on the skin, but do not work in pairs. Expressions of the face require little contraction. The facial muscles would be classified under the superficial layer.
Muscles of the Back
- Levator Scapulae- This muscle is designed to lift the scapula bone.
- Tres Major – A thin muscle that covers the underarm.
- Tres Minor- A smaller muscle above the tres major.
- Trapezius- It is another muscle that goes from occipital bone to the spine of the scapula.
- Infraspinatus- One of the muscles of the rotator cuff and responsible for the movement of the humerous bone. It also stabilizes the shoulder joint.
- Semispinalis- A total of three muscles situated around the spinal cord.
- Rhomboideus major- responsible for connecting the scapula to the vertebrae
The back has sheets of muscle. The critical points are the shoulder joints, which are essential for motion of the arms. The muscles of the front of the body are easily recognizable.
- Pectoralis Major- located in the chest
- Serratus Anterior- Surround the rib cage
- Rectus Abdominis- Located on the stomach
- Tensor Fasciae
- External obliques
- Linea Alba
Muscles of the Legs
- Vastus lateralis
- Tibialis Anterior
- Adductor Longus and Adductor Magnus
- Rectus Femoris and Biceps Femoris
- Peroneus Brevis
- Gluteus Maximus
Muscles of the Arm
- Biceps Brachii
More detailed analysis will follow of the physiological and chemical properties of the muscular system.