Unit 8: Musculoskeletal System
Introduction
The musculoskeletal system provides stability, form, and movement in the human body. It
comprises of bones (which makes up the body’s skeleton), cartilage, joints, muscles, tendons,
ligaments, and other connective tissues. Connective tissue refers to the tissue responsible for
providing support and connecting various tissues and organs within the body. Its main
elements are collagen and elastic fibres, which are composed of different proteins.
The skeleton gives the body shape, supports the weight of the body, and shields its organs.
Muscles from the muscular system attach to these bones, pulling on them and allowing the
body's movement.
The Human Skeleton
The skeleton is made up of the bones of the body. A fully grown adults would have 206 bones
as part of their skeleton. Younger individuals would have a higher number of bones; however,
they fuse together as they grow older during childhood and adolescence to form an adult
bone. The main purpose of the skeleton is to provide a fixed endoskeleton, which supports
the weight of the body against the force of gravity, and to provide a rigid structure where the
muscles produce movement to the body. The lower extremity of the body specialises in
stability, mainly whilst crawling, walking, running, etc. On the other hand, the upper extremity
has greater moveability, which is perfect for lifting and carrying objects.
Whilst providing movement and support for the body, the skeleton also serves for protection
and storage functions. The skeleton shields the organs such as the brain, heart, lungs, pelvic
organs, etc. the bones of the skeleton store important minerals such as calcium and
phosphate. The bone marrow in the
bones stores lipids and houses the
tissue that produces blood cells.
Axial and Appendicular Skeleton
The skeleton in the human body is
divided into two parts, axial and
appendicular skeleton. As you can see
on the diagram to the right, the axial
skeleton includes all the bones of the
head, neck, chest, and the back. It
provides protection and support for
the brain, spinal cord, and the organs
in the ventral body cavity.
, The appendicular skeleton comprises of the upper and lower extremities, including the
shoulder girdle and the pelvis. The shoulder girdle and the pelvis provide connection points
between the axial skeleton and the appendicular skeleton to where mechanical loads
transfer.
Different Types of Bones
The human skeleton has multiple functions, such as supporting weight and protection.
Diverse types of bones have different shapes related to their specialised function. There are
five types of bones: long bone; short bone; flat bone; irregular bone; sesamoid bone.
Long Bone
