Skeleton system is the framework of the body comprising of bones, joints, tissues and other parts. There are two types of skeletal system : Exoskeleton and Endoskeleton.
Exoskeleton refers to the external skeleton which protects our body and it is very hard. Endoskeleton is the interior skeleton which contains the vertebrates. The term "exo" mentions outside and the term "endon" mentions inside.
Bones :
There are totally 206 bones adult's body. However, babies have 300 bones! It fuses gradually due to our growth. Thus, the adults have lesser number of bones in compared to babies. Bones frame the shape for the body. They are very essential. They all present in any parts such as the shoulder bones, pelvic bones, backbone, the ones in the rib cage and etc.
Joints :
The place where two bones meet is known as a joint. The joint allows the movement of bones. There are movable and immovable joints. The movable joints allows movement in different directions. The immovable joints are fixed in one place and doesn't allows movement.
Types of Movable Joints :
1. Pivot joint - It is present in our necks.
2. Hinge joint - It is present in elbows and knees.
3. Ball and Socket joint - It is present in hips and shoulders.
4. Gliding joint - It is present in wrists and ankles.
1. Skull
TheSkull is the major bone as it protects our brain. There are totally 22 fixed joints present here. It is a immovable joint. The lower jaw is only movable in the skull.
2. Ribs
Our heart, lungs and other internal organs are safe because of the ribs. These bent bones located in the chest are ribs. There are 12 ribs.They join the chest bone and backbone to form a cage known as the ribcage.
3. Hand
We use our fingers for various purposes. The wrist is made up of many tiny bones called carpels. Our arm is made up of three kinds of bones namely - humerus, radius and ulna. Hemures is above our elbow. The radius and ulna are below our elbow.
4. Legs
A place where our legs are attached to a round group of bones are called the pelvic bones. A bone that is present in our thigh region is called the femur bone. It is the longest bone in our body.
5. Interesting Facts :
1. Our ears contains a hard bone - like structure known as a cartilage. Anyhow, cartilages are not as hard as bones. Moreover, it is also the smallest bone.
2. The longest bone in the human body is the femur.
3. Very minute number of people are born with 13 bones!
4. About 106 bones are situated in the hands and feet.
5. Osteonecrosis is one of the most dangerous bone disease.
