All about the skeletal system

Our vertebral column is formed by 26 serially arranged units called vertebrae and is dorsally placed

Hyderabad: This article is in continuation to the previous articles focusing on Locomotion and Movement. Today’s article will deal with the working of the skeletal system.

Skeletal system

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• Skeletal system consists of a framework of bones and a few cartilages.

• This system has a significant role in movement shown by the body.

• Imagine chewing food without jaw bones and walking around without the limb bones.

• Bone and cartilage are specialised connective tissues.

• The former has a very hard matrix due to calcium salts in it and the latter has slightly pliable matrix due to chondroitin salts.

• In human beings, this system is made up of 206 bones and a few cartilages.

• It is grouped into two principal divisions – the axial and the appendicular skeleton.

The Axial skeleton

• Axial skeleton comprises 80 bones distributed along the main axis of the body.

• The skull, vertebral column, sternum and ribs constitute axial skeleton.

The skull

• The skull is composed of two sets of bones – cranial and facial, that totals to 22 bones.

• Cranial bones are 8 in number. They form the hard protective outer covering, cranium for the brain.

• The facial region is made up of 14 skeletal elements which form the front part of the skull.

• A single U-shaped bone called hyoid is present at the base of the buccal cavity and it is also included in the skull.

• Each middle ear contains three tiny bones – Malleus, Incus and Stapes, collectively called Ear Ossicles.

• The skull region articulates with the superior region of the vertebral column with the help of two occipital condyles (dicondylic skull).

Vertebral Column

• Our vertebral column is formed by 26 serially arranged units called vertebrae and is dorsally placed.

• It extends from the base of the skull and constitutes the main framework of the trunk.

• Each vertebra has a central hollow portion (neural canal) through which the spinal cord passes.

• First vertebra is the atlas and it articulates with the occipital condyles.

• The vertebral column is differentiated into cervical (7), thoracic (12), lumbar (5), sacral (1-fused) and coccygeal (1-fused) regions starting from the skull.

• The number of cervical vertebrae is seven in almost all mammals, including human beings.

• The vertebral column protects the spinal cord, supports the head and serves as the point of attachment for the ribs and musculature of the back.

By

Dr. Modala Mallesh

Subject Expert

Palem, Nakrekal, Nalgonda

9989535675