Skeletal system, Importance of Cartilages, Joints, Ligaments & Tendons
Cartilages are a type of connective tissues that consists of cartilaginous cells, They do not contain blood vessels, So, they get food and oxygen from the bone cells by diffusion, Cartilages protect the bones from corrosion, as a result of the continuous friction between them.
In the human skeleton, there are three types of joints which are:
- Fibrous joints: These joints connect the bones of the skull together through its serrated tips, They don’t allow movement, The bones are fused with fibrous tissues at these joints and by growing older, these fibrous tissues change into bony tissues.
- Cartilaginous joints: They are joints that connect between the ends of some adjacent bones, They allow a very limited movement, They are found between the vertebrae of vertebral column.
- Synovial joints: They represent most of body joints, They are flexible joints which bear shocks (trauma), They allow the movement easily, where:
The bones which in contact with these joints are covered with a delicate layer of a transparent smooth cartilaginous substance which allow the movement of bones easily with less friction, They contain a synovial fluid which facilitates the sliding of cartilages that cover the tips of bones.
The synovial joints are divided according to their movement into Limited movement joints and Wide movement joints:
- Limited movement joints are joints which allow the movement of one of the bones in one direction only such as elbow joints and knee joints.
- Wide movement joints are the joints which allow the movement of the bones in many different directions such as shoulder and hip joints.
They are separated bundles of fibrous connective tissue, where their tips are fixed on the two bones of the joint, Their fibers are characterized by:
- being strong and durable.
- The presence of a degree of elasticity to allow a little increase in their length, in order not to be cut during the exposure of the joint to external pressure.
Example: Ligaments of the knee joints which are:
- Anterior of the cruciate ligament.
- Posterior cruciate ligament.
- Medial collateral ligament.
- Lateral collateral ligament.
In some cases, the ligaments may be ruptured, due to the twisting of some joints as in the case of the cruciate ligament in the knee joint.
Its importance: Achilles tendon connects the gastrocnemius muscle with the heel bone.
Damage of Achilles tendon
- vigorous effort
- Sudden contraction of gastrocnemius muscle.
- Loss of elasticity in the gastrocnemius muscle.
- The inability of walking.
- Acute pain.
- Heavy movement of the foot.
- Using anti-inflammatory and analgesic drugs.
- Using a medical splint.
- Surgical intervention which does not carry out, except during the complete tearing of the tendon.