The skeletal system in human is a major connective tissue system that is made up of organs, such as bones, ligaments, tendons and cartilages. The entire framework of body is made up of bones, which serves as a guarding system to protect the viscera and allows locomotion. Two bones are connected by fibrous tissues that are called ligaments; whereas the muscles are connected to the bones by tendons. These connections provide the system with greater range of motion and strength. Soft parts such as nose and ear are made up of flexible connective tissues called cartilages which further protect the bones. These different parts make up organs of human skeletal system. The skeletal systems in male and female are a bit different in a few aspects, such as female pelvis is more flat and round so as to support the childbirth. Similarly the pelvic angles and inlets are also different, such as angle in males is 90 degrees while that in females is 100 degrees.

What Are Human Skeletal System Organs?

1.       Bones

The most important organ of the skeletal system is the bones. Human skeleton is made up of 206 bones that in coordination not only provides support and protection to the viscera (with the help of muscles attached to them) but also produces blood cells for the body from the bone-marrow.

 2.  Ligaments and Joints

Another important component, i.e. the ligaments are made of fibrous collagen tissue that attaches one bone to another bone. This attachment forms into joints and allows the bone to move in a particular direction and hence enhances the movement of body parts in desired direction, such as hips, elbow, knees ad wrist etc. If the stretching of ligament occurs more than the normal levels, the person is referred to as double-jointed.

3.       Tendons

Similar to ligaments, tendons are important skeletal system organs which join the muscles to the bones, hence they are more flexible so as to provide greater range of movement. The contraction of tendon pulls the end of bone to which it is attached and makes that bone to move during walking and running. But this excessive flexibility of tendons make them more prone to injuries and infections. One such inflammatory conditions is known as tendonitis, in which the tendons get red, swollen and painful to move.

4.       Cartilage

Another organ of skeletal system is the cartilage, which is soft and flexible connective tissue. Cartilage not only plays a role in maintaining and forming the shape of human ear and nose as well as other organs, but also protects the bones against friction forces (which would otherwise corrode the bones easily). The cartilages can also get damaged or infected, causing the joint to be swollen and tender. In advanced cases, you may require repair or replacement such as knee replacement surgery.

Divisions of Human Skeletal System

Human skeleton organsare divided into two types, the appendicular skeleton and the axial skeleton. The axial skeleton runs in the midline i.e. the axial plane of the body and is made up of a total of 80 bones. The axial skeleton forms the central axis and provides protection to vital viscera, such as brain protected by skull, heart and lungs protected by the ribs cage and spinal cord protected by vertebrae. On the other side, the appendicular skeleton forms the body limbs, and is made up of 126 bones in total. The most important function of appendicular skeleton is to provide movement and locomotion.

Axial Skeleton

It contains the following from top to bottom respectively:

• Skull- it includes the cranium, face and auditory ossicles.
• Hyoid- bone of neck for muscles attachment of chin and larynx.
• Vertebral column- consist of all spinal vertebrae.
• Thoracic cage- it contains ribs and sternum.

Appendicular Skeleton

It contains the following from top to bottom respectively:

• Shoulder girdle- it includes clavicle and scapula.
• Upper limb- it contains arm, forearm and hand’s bones.
• Hip girdle- it includes hip bone.
• Lower limb- it contains leg and feet’s bones.

Classification of Bones Based on Shape and Size

The bones of human skeletal system are classified in to four distinct groups on the basis of size and shape. They are long bones, short bones, flat bones and irregular bones.

The bones of arms and legs are long in length as compared to their width. Thus these are categorized under long bones. Similarly the bones of ankle and wrist are short and cuboidal with almost same length as compared to their width. That’s why they are called the short bones. The bones of ribs and cranium are thin, broad and curved. They are called flat bones. All those bones which do not have a particular shape, and cannot be classified as long, short and flat are called irregular bones, such as hip bones and vertebrae.

Skeletal System Diseases

Following are some major diseases of the skeletal system which affect the above mentioned skeletal system organs:

How to Keep Skeleton System Organs Healthy

• Take Calcium rich diet, containing 1000mg calcium per day in the form of milk, cheese, broccoli, orange and salmon etc.
• Take vitamin D rich diet, containing 15mcg vitamin D per day for an adult in the form of eggs, fish, orange and cereals etc.
• Do weight bearing exercisesdaily or at least 30 minutes twice a week so as to make your bones strong in the form of pushups, sit-ups and squats etc.