- The skeletal system includes all bones of the body and associated cartilages, tendons and ligaments.
Bones can be classified into five categories on their shape: long, short, flat, irregular and sesamoid. .
Classification of bones is as follows:
- Long bones
Length of these bones exeeds the width. It consists of diaphysis and two epiphysis. The epiphysis consists of an outer thin covering of compact bonewithcancellousbone inside that usually red marrow is found.
Ex: femur, tibia,fibula and hemuras.
- Short bones
They do not have shafts but nearly cubic shape and are equal in length and width.
Ex: carpels (wrist) and tarsals (foot).
- Flat bones
Thin bones present in areas where extensive muscle attachment is required or or areas which protect the soft or vital parts of body. These are usually curved and consists of two flat plates of compact bone tissues enclosing a layer of cancellous bone.
Ex: sternum, ribs and most skull bones.
- Irregular bones
These are irregularly shaped.These consists of cancellous bone enclosed by relatively thin layers of compact bone.
Ex:vertebrae,ossicles(ears) and some skull bones.
- Sesamoidbones
Small rounded bones which assist in functioning of muscles. These are located adjacent to joints.
Ex: Patella(knee cap)
Functions of skeletal system are:
- Support
Serves as structural framework of boby. It give attachments to muscles and tendons.It supports and stabilizes supporting tissues like muscles, blood vessels,nerves,fat and skin.
- Protection
It encoses vital organs like brain, lungs,heart and protects them from injury.
- Assists in movement
It forms joints because of which part of body or whole body can move.
- Haemopoiesis
The red bone marrow, a connective tissue present within certain bones produce RBC, WBC and platelets.This process is Haemopoiesis.
- Mineral Homeostatis
Serve as storage for mineral salts, especially phosphorous and calcium which strengthens bone.Bone ensures Mineral Homeostatis in body by releasing minerals into blood when required.
