Question

The functions of the axial skeleton are
A. To make locomotion possible
B. Protect organs of excretion
C. Protect organs of digestion
D. All of the above

Answer 1

Hint: The axial skeleton refers to the part of the skeleton consisting of bones of the head, vertebrae, and trunk. It consists of 86 bones. It provides a site for attachment of other bones and muscles of the body. It is named axial as it is located close to the central axis of the body.

Complete answer: The axial skeleton along with the appendicular skeleton makes up the complete human skeleton. The axial skeleton is located near the central axis of the body due to which it is called the axial skeleton. It is composed of 80 bones and six distinct parts. 22 out of 80 bones make up the skull. The other parts are the ossicles of the middle ear, hyoid bone, sternum, rib cage, and the vertebral column. Thus, the axial skeleton is the part of the skeleton consisting of the bones of the head, the trunk, and the vertebrae. It connects the pelvis to the body.

The flat bones of the skull house the brain and other sensitive and vital organs of the head. With age, the bones get weaker but the skull always remains strong so as to protect the brain from any injury. It further consists of cranium and facial bones. The additional smaller spaces like cavities for the eyes, the internal ear, the nose, and the mouth are all made by 22 bones of the skull. The main functions of the skull are to protect the brain and other vital organs along with keeping the eyes and other structures of the face in their place. The rib cage is the second part of the axial skeleton. It is composed of 12 pairs of ribs and a sternum for a total of 25 separate bones. It also protects the vital organs of the body like the heart and lungs. This region of the axial skeleton covers the digestive as well as excretory organs. The rounded ends of the ribs are attached to joints of the thoracic vertebrae at the back. The vertebral column is the third component of the axial skeleton that makes up the 33 separate vertebrae columns in humans. It consists of 5 different parts. The uppermost part is the cervical that makes a junction between the vertebral column and the cranium. The next part is thoracic, then lumbar, then sacral which makes a junction between the vertebral column and pelvic bones. The last part is the coccygeal vertebrae. Hence, from the above discussion, we can conclude that the axial skeleton provides a site for attachment for other bones and muscles. It protects organs involved in excretion and digestion. It also protects the blood vessels and nerve fibres from the brain and spinal cord. The axial skeleton also functions in locomotion as it is attached to the pelvic region.
Hence, the correct answer is option D.

Note: The second part of the skeleton is the appendicular skeleton. As its name suggests it is composed of bones that support the appendages. It is made up of a total of 126 bones. Limbs, supporting shoulder girdle pectoral, and pelvic girdle are parts of the appendicular skeleton system.