Difference Between Axial and Appendicular Skeleton (With Table)

The human body is a complicated science of nature in existence to date. It is internally framed by a skeleton and entirely covered with skin.

Skeleton is not just bones; it is also the teeth. The human skeleton forms the base for the shape and functionality of the human body. It contains around 270 bones by birth and gets reduced to 206 by adulthood as few bones fuse for body development.

The human body is made of one skeleton and it is divided into two major regions. They are called Axial and Appendicular Skeleton.

The human skeleton composed of Axial and Appendicular performs six important functions. They are support, movement, protection, blood cell production, mineral storage and regulation of endocrine. Both the regions of the human skeleton are important in their own characteristics.

Axial vs Appendicular Skeleton

The main difference between Axial and Appendicular skeleton is that the axial skeleton is the central axis of the body whereas the appendicular skeleton is mainly limbs and appendages.


 

Comparison Table Between Axial and Appendicular Skeleton (in Tabular Form)

Parameter of Comparison

Axial

Appendicular

Definition

Axial Skeleton of the human body forms the central axis of the skeletal system. In other words, the Axial skeleton forms the midline of the body.

Appendicular Skeleton of the human body is the limbs and appendages. In other words, all the bones apart from Axial bones are appendicular and they facilitate linkages for all the parts of the skeleton.

Main Functions

Axial Skeletal bones are required mainly for Posture, Balance, and Stability.

Appendicular Skeletal bones are required mainly for locomotion, digital manipulation leading to reproduction and feeding.

Parts of Skeletal System/ Bones

The axial skeleton consists of the following bones, Skull, facial bones, hyoid bone, rib cage, and the vertebral column.

The appendicular skeleton consists of Arms, Forearms, pectoral girdles, pelvis, legs, ankle and feet.

Total number of Bones

Axial Skeleton consists of 80 bones on the overall.

Appendicular Skeleton consists of 126 bones on the overall.

Skeletal Nature at Adult hood

The Axial Bones are fused.

The Appendicular bones are not fused.

 

What is Axial Skeleton?

Axial Skeleton is one region of the human skeletal system which forms the central axis, which is the mid-line of the human body. Axial Skeleton is majorly required for good posture, balance, and stability of the body.

Axial Skeleton consists of 80 bones in the human skeleton. It is also composed of six parts in the skeletal system: Skull, Facial Bones, Ossicles of the middle ear, Hyoid Bone, rib cage, sternum, and vertebral column.

The other way of defining the Axial skeleton is the bones which include Sternum, ribs, vertebrae, sacrum, and coccyx. The Axial bones are almost fused while reaching adulthood.

While the Axial bones get fused upon growth, it is also observed that a few bones of axial skeleton also get weaker. The main exception of this aspect is the skull, it remains strong throughout the life span of a human.

The axial bones in several parts of the skeleton have their share of bones for the proper functionality of the body. The human skull that includes the facial bones has 22 bones in total.

The rib cage has 12 pairs of bones with a sternum that makes it to 25 bones. The vertebral column is composed of 32 to 34 bones which indeed will get fused to 24 by adulthood.

 

What is Appendicular Skeleton?

Appendicular Skeleton is one region of the human skeletal system which forms the limbs and appendages. Appendicular Skeleton is majorly required for the movement of the body and also digital manipulation of feeding and reproduction.

Appendicular Skeleton consists of 126 bones in the human skeletal system. They are present in the skeletal elements of the limbs, pectoral and pelvic girdle. The appendicular skeleton consists of six major areas in the human skeletal system. They are shoulder girdles, Arms and Forearms, Hands, Pelvis, Thighs ad Legs, Feet, and Ankles.

It is to be known that; Appendicular skeletons are not fused. This can massively allow motion of the body. Out of 126 bones, the shoulder girdles consist of 4 bones, the left, and the right. This connects the limbs to the central axis of the body.

Arms and Forearms are made of 6 bones altogether, while the Pelvis has 6 bones too. Thighs and legs comprise of 8 bones and one of the strongest bones in the body.

The hands, feet, and ankles take the major share of the bones in the appendicular skeleton. They have a total of 106 bones altogether.

The hands comprise 54 bones while feet and ankle have 52 bones in the human skeleton.


Main Differences Between Axial and Appendicular Skeleton

  1. Both the regions of the human skeleton are of prime importance for the proper functioning of the body. The main difference between Axial and Appendicular skeleton is, axial skeleton forms the central axis of the body while the appendicular skeleton forms the limbs and appendages.
  2. The Axial Skeleton is required for good posture, balance, and stability of the body whereas the appendicular skeleton mainly helps in the movement of the body. Further digital manipulation of feeding and reproduction also happens with the help of the appendicular skeleton.
  3. There is a total of 80 bones in the axial skeleton whereas the appendicular skeleton consists of 126 bones.
  4. The Axial bones are fused whereas Appendicular bones are strong and never fused.
  5. The axial bones are Skull, Rib Cage, Vertebral Column, Ossicle of the outer ear, hyoid bone and sternum whereas the appendicular bones are pectoral and pelvic girdle along with forearms, hands, feet, ankle.

 

Conclusion

The human skeleton is a strong framework upon which the body functions smoothly. The axial and appendicular skeleton has its own functionalities which keep the body stable and in movement.

How far, balance in the body is important is as far the movement is also important. It is also observed that the intake of calcium-rich food help bone gets stronger. It is also scientifically proven that; with age few axial bones get weaker.

But appendicular bones are always strong. With the help of these two main regions of the human skeleton, the six major functions of the body; Support, Movement, Blood Cell Production, Mineral Storage, Protection and regulation of endocrine are intact.


 

References

  1. https://academic.oup.com/jcem/article-abstract/83/5/1420/2865113
  2. https://anatomypubs.onlinelibrary.wiley.com/doi/abs/10.1002/dvdy.1120
  3. https://www.nejm.org/doi/full/10.1056/NEJM196507082730203