The Musculoskeletal System
The musculoskeletal system contains your bones, muscles, tendons, and ligaments. It has 3 main
functions which include Supporting the body, motion and protecting important organs. The skeleton
provides support, protection, production of red blood cells, storing minerals, maintenance of
mineral homeostasis and movement. It works in conjunction with skeletal muscles which provide
movement, posture, joint stabilisation, and heat generation. Tendons and ligaments are also part of
the musculoskeletal system where the tendons connect muscle and bones, and the ligaments
strengthen joints between bones.
Bones
Figure 1 - Mr Bones
The skeletal system has two types of skeletons one called the Axial Skeleton that consists of the Skull
to protect the brain, the Vertebral Column which surrounds the spinal cord and the Rib Cage that
protects the lungs and heart. The other one is called the Appendicular skeleton which includes the
arm bones, shoulder girdle, leg bones and pelvis all of which are connected to the axial skeleton
Bones are made of a mix of collagen and calcium phosphate which make them strong and slightly
springy whilst also making sure they don’t weigh you down. They protect vital organs and work with
muscles to allow movement. There are five types of bones as shown in the table below.
Name of Bone Description Function Example
Long Bones A long shaft with two Contain bone marrow Femur, Tibia, Fibula,
bulky ends to produce blood cells Humerus, Radius and
Made of mainly Support the body Ulna
compact bone with a Allow movement
, large amount of
spongy bone at each
end
Short Bones Roughly cube shaped Allow more Tarsals and Carpals
Have the same movement
structure as long Provide stability
bones but shorter
Flat Bones Thin and flat and Protect internal Cranium, Sternum,
usually curved organs ribs, and scapula
Sesamoid Small round and Protects tendons Patella
imbedded in the
tendons
Irregular Bones Usually, spongy bone Support the body Vertebrae, Sacrum
covered in a thin layer and Pelvis
of compact bone
Figure 2 - Muscle Man
Muscles
They are made of muscle cells. Some move with our control and some work unconsciously keeping
you alive. There are three main types listed in the table below.
Name Description Function Example
Skeletal Made up of bundles of Movement Quadriceps and Biceps
muscle fibre that
contract and relax for
movement
Smooth Made of long cells Form organs such Stomach and
connects in sheets stomach, intestines, Intestines
which form parts of and oesophagus
your organs
Cardiac A muscle that never To keep your heart Heart
