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 .
Cartilages found usually at the tips of bones , especially at the joints and between the vertebrae of vertebral column , The cartilages from some body parts such as ears , nose and bronchioles of lungs .
In the human skeleton , there are three types of joints which are :
- Fibrous joints : These joints connect the bones of 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 an 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 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 .
- Inability of walking
- Acute pain
- Heavy movement of 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 .