Framing the Organic Machine: The Skeletal System


The skeletal system acts as a framework: supporting the body, protecting internal organs, providing storage for minerals, and serving as a lever system for muscular action. The main components of the skeletal system are bones, cartilage, tendons, ligaments, and joints. 

There are 206 bones that serve as the rigid support structure of the body and are connected via ligaments. Bones are also connected to muscles by tendons, allowing you to have motion. Further, cartilage often forms the mold for new bone growth and cushions joints between the bones.

Just like a tower, your body has an inner frame to support its structure.

Basic Anatomy of the Skeletal System

Axial and Appendicular Skeletons

The skeletal system is subdivided into two divisions: the axial skeleton and appendicular skeleton. In the diagram below, the axial skeleton is highlighted in red and the appendicular skeleton is highlighted in blue.

As shown, the axial skeleton houses the skull, vertebral column, and thoracic cage (ribs and sternum). The primary function of this division is protection of the brain, spinal cord, heart, and lungs. The appendicular skeleton includes everything necessary for the appendages, including the shoulder girdle, hips, and the bones of the legs and arms. The primary function of this division is to allow for movement as the bones that make it up are responsible for our ability to walk, run, lift, or even wave hello.

The Vertebral Column

The vertebral column, or spine, is composed of four vertebrae sections: cervical, thoracic, lumbar, and the sacrum. First, the seven cervical vertebrae are responsible for supporting the head and allowing movement of the neck. Second, the twelve thoracic vertebrae are responsible for providing the foundation for the ribs and thoracic cage. Third, the five lumbar vertebrae support the lower back and the majority of the weight of the upper body. Lastly, the sacral vertebrae consists of five fused vertebrae at the base of the column. The coccyx is just below the sacrum and is also known as the tailbone. Each vertebrae is separated by an intervertebral disc that absorbs shock to cushion the vertebrae.

Drinking milk is a great way to support bone health!


There are over 300 joints in the adult human body. Joints, also called articulations, perform two main functions: holding bones together and allowing flexibility in the rigid skeletal system for large-scale movements. The diagram below is an example of a synovial joint. In this type of joint, each end of the connected bones is covered with articular cartilage. This extends out and around the joint to form the articular capsule. The capsule is then supported by a loose synovial membrane on the sides and is filled with synovial fluid. The goal of synovial joints is to reduce friction and absorb shock during body movements.

To explore the skeletal system in more depth visit this site, which is backed by medical professionals.

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