Musculoskeletal: Functions

Locomotor
We will discuss:
Muscles
Bones
Joints, ligaments and tendons

The motor activities of the organism are not only demonstrating the possibility of moving as a whole in space and changes of position but also by the activity of many visceral organs.

Muscles
There are three types of muscle: striated (somatic, skeletal), cardiac (myocardium) and smooth (visceral). Muscle cells are elongated, and are therefore called fibers. The myofibrils of smooth muscle fibers are apparently homogeneous, but the striated muscle of different areas have alternately refraction because of the protein myosin and actin. Somatic striated muscles are more or less directly related to the skeletal system and are involved in the movement of the skeleton, while the motor activity of internal organs (except heart) is the responsibility of the smooth muscles. The skeletal muscles are fast twitch, are innervated by the somatic nervous system and voluntarily modify their activity. By contrast, smooth muscles are slow twitch and are innervated by the autonomic nervous system and its activity is involuntary. The shortening of a muscle fiber is the result of sliding of actin filaments over myosin in myofibrils, which reduces the distance between the bands Z. The energy for this process comes, ultimately, conversion of glycogen to lactic acid and burning it to form CO2 and water. The changes of position and movement is made possible thanks to the contraction of the somatic striated muscle.

Bones
The bone material is arranged in concentric layers around a few channels that form the so-called Haversian system and serve as distribution via the blood vessels. The bones are very different shapes and sizes. Its shape is divided into long, flat and irregular. Are distinguished by their structure the compact and cancellous bone.

Joints, ligaments and tendons

They are called joints at the connection between two contiguous bones. Are classified as sinartrosis (as the sutures of the skull bones), cartilaginous joints (the joint between the vertebrae) and synovial joints, where mobility is possible.

Ligaments are connective tissue masses ranging from bone to bone on both sides of the joints. The tendons allow connection of muscles to bones.

Related Topics

* Respiratory
* Sensory apparatus
* Urinary
* Circulatory System
* Nervous System
* Gastrointestinal

*Automatic Translation