Q.4 What are the components of human skeleton?
Introduction
206 bones are present in the adult human skeleton. Skeleton can divide into two parts:
1. Axial Skeleton
Bones are organized into a longitudinal axis i-e axial skeleton. Axial Skeleton consists of 80 bones in the head and trunk of body.
Parts
It is composed of five parts:
i Skull Contains 22 bones out of which 8 are cranial bones (enclosing the brain) and 14 are facial bones.
ii. Middle ear ossicles 6 bones are present in middle ear (3 in each ear).
iii. Hyoid bone It is present in neck.
iv. Vertebral column It contains 33 bones and these bones are called vertebrae.
v. Chest Chest is made up of a chest bone called sternum and ribs. 24 ribs are present in 12 pairs.

2. Appendicular skeleton:
Apendicular skeleton is attached to the axial skeleton. Appendicular skeleton is composed of 126 bones.
Parts
It is divided into two parts.
1) Pectoral Girdle (Shoulders): It is called shoulder girdle and made up of 4 bones. Arms have six
bones. Both hands have 54 bones.
2) Pelvic Girdle (hips): It has two bones. Legs have 6 bones and feet have 54 bones.