Functions of the musculoskeletal system
• Gives structure and form to the body
• Protects vital structures
• Mobility
• Dexterity
What is the musculoskeletal system?
• Bones of the skeleton
• Muscles
• Joints
The Skeleton is made up of Bones - What do bones do?
• Movement
• Support and protection of internal organs
• Store of minerals
• Produce blood cells
What features do bones need?
• Strong
• Resilient
• Light
• Able to respond to stresses and strains and to repair
Bones of the Skeleton
Axial Skelton
• Skull
• Spine or vertebral column
• Ribs
• Sternum
• Pelvis
Appendicular skeleton
• Shoulder and arms
• Hips and legs
Structure of Bone - Bone is a living structure, always being made and taken away, responding to forces applied to it and able to repair:
• Compact bone
– Dense bone on the outside of all bones, forming the tube of the long bones
• Trabecular bone (spongy, cancellous)
– Meshwork of bone that gives strength at a low weight. The spaces between the bone struts (trabeculae) are filled with bone marrow – blood making cells
Composition of Bone
• Bone cells
– Osteoblasts – make osteoid that becomes mineralised to form bone
– Osteoclasts – remove bone
• Mineral salts
– mainly calcium in the form of calcium hydroxyapatite crystals
– give bone its hardness and is why bones show up on x-rays
• Collagen fibres
– proteins that calcium salts are embedded around
– give bone the ability to bend under strain
Joints
• What do joints do?
– Provide the link between bones
– Enable movement
– Need to be stable
• Types of joints
– Fibrous
surfaces joined by fibrous tissue
– Cartilagenous
bones joined by cartilage
– Synovial joints
bone ends covered in cartilage; capsule surrounds joint lined with synovium; stabilised by shape, ligaments and muscles; important for movement
Synovial Joint
• Bone ends covered in cartilage
• Capsule surrounds joint and creates a joint space containing synovial fluid
• Capsule lined with synovium produces synovial fluid
• Ligaments, muscles and boney shape give stability to the joint
Types of Synovial Joints
Muscles
• Muscles are made up of muscle fibres that can contract (shorten). This ability is central to their function
• There are 3 types of muscles
– Skeletal muscle – attached to bones and essential for movement and posture
– Smooth (involuntary) muscle – in blood vessels and hollow organs such as oesophagus, stomach, intestines, bladder
– Cardiac muscle – only found in the heart
• Skeletal muscles
– Can be made to relax or contract by nerve impulses
– Made up of hundreds of thousands of individual muscle fibres which have a stripped appearance down a microscope
– Some are able to contract very rapidly to enable movement, like running
– Some are better suited for constant contraction to give stability, like when standing
– They are attached to bones by tendons
– They enable movement by the principle of levers
Skeletal muscle fibres
The most important function of the musculoskeletal system is movement
• Walking and running
• Getting up and down
• Gripping things
• Picking things up
• Lifting and carrying
• It works by the principle of levers
Written by an EEFO.net user
Comments
Do you have any comments to add to this article? Do you agree with what's been said? Have you experienced the same issue? Have you got any advice you'd like to pass on to other eefo.net users? If so, then please click below... Your comment will be added to the bottom of this article.
Add Your Comment
Rate this article
