Unit 3. We protect our bones and muscles

 

       Unit 3. We protect our bones and muscles.

The locomotor system is also known as the musculoskeletal system. It is made up of the skeleton, the skeletal muscles, tendons, ligaments, joints, cartilage and other connective tissue. These parts work together to allow movement.

In the locomotor system or musculosketal system we have 2 systems: Skeletal system and muscular system.

The skeleton

The skeleton is made up of 206 bones. Bones are a form of connective tissue reinforced with calcium and bone cells. Bones have a softer centre, called marrow, where blood cells are made. The three main functions of the skeleton are:

• support – the body is supported and shaped by the skeleton – for example upright posture would be impossible without a spine
• protection – our internal organs are protected by our skeleton, such as the brain inside the skull, the heart and lungs inside the ribcage
• movement – most skeletal muscles are attached to bones in opposite working groups, like the biceps and triceps muscles of the upper arm.

The skeleton also stores minerals (such as calcium) and lipids (fats), and produces blood cells in the bone marrow.

Skeletal muscles work in pairs

Generally, muscles move the skeleton by working in opposite pairs. For instance, if you bend your elbow, your biceps (muscles on the front of the upper arm) contract and the triceps (muscles on the back of the upper arm) relax. It works the other way if you straighten your arm – the triceps contract while the biceps relax.

In some joints, like the shoulder joint, many different muscles are attached. This allows even greater freedom of movement.

Common problems of the locomotor system

Some common problems of the locomotor system include:

• arthritis – problems within the joints, such as inflammation
• osteoporosis – occurs when bones lose minerals such as calcium more quickly than the body can replace them. They become less dense, lose strength and break more easily
• bone fractures – caused by falls or accidents
• back pain and neck pain
• inflammatory disease.
• overuse or mechanical injuries such as tendonitis, muscle or ligament strains

IMPORTANT QUESTIONS.

  What is the locomotor system?

   How many bones do we have?

  Are bones living things?

 What are the functions of the bones?

What are antagonist muscles?

What are the functions of the bones?

What are the functions of the muscles?