Osseous tissue is a tissue of the skeletal system otherwise commonly known as bone tissue. It is the major connective tissue of the human body. It consists of two types of bone; Compact bone forms the outer layer of bones and various structure of long bone. It is composed of bone marrow and medullary cavity; it helps long bone to maintain the weight of our human body. It includes osteons. Second type is spongy bone. It consists of a lattice and trabeculae. It is not include osteon. Haversian canal forms Haversian system and is in osteon. 
Osseous tissue has two types of bone: compact bone and spongy bone.
Compact bone, known as Cortical bone, is one of the two types of osseous tissue. It is dense bone matrix enclosing only a few small spaces, forming the outer layer of all bone. It is denser than cancellous bone. Moreover, it is more strong and stiff because cancellous bone supplies about 80% of the weight of a human skeleton. It is very lightweight, but easily can endure stress. Its main functions are support organs and the whole body and store chemical elements like calcium. Compact bone has two functional units- osteons and haversian systems.
Spongy bone, known as cancellous bone or trabecular bone, is one of two types of osseous tissue. It is made of trabeculae and less dense and stiff. It usually shows at the ends of long bones. Cancellous bone is vascular and usually has red bone marrow. Difference between compact bone and spongy bone is the absence of osteons. Cancellous has Latin name: substantia spongiosa or substantia spongiosa ossium.
Osseous tissue directly or indirectly contributes for the whole body by its main functions. Directly, osseous tissue supports and protects organs, muscles, and the whole body. Moreover, it leverage and movement. Indirectly, it is hemopoiesis: formation of blood cells. Osseous tissue helps to maintain the human body. It is also very important because it contains calcium and phosphate.
Osseous tissue sometimes does remodeling or reorganization due to some factors:
- Mechanical stimuli
- metabolic causes
- endoctrine causes
- effects of drug 
It is very important that functions of osseous tissue. At first, it needs to support. It maintains human body, so it is very important part. Second, it provides mechanical protection to reduce the risk of injury. Third, it assists in human body's movement. Fourth, osseous tissue makes the various minerals storage like calcium(Ca) and phosphorus(P). Five, osseous tissue products of blood cells like red blood cells and white blood cells. Last, it also contains chemical energy.
- Osseous tissue Wikipedia, Wikimedia Foundation, Inc., 2 January 2011.
- structures and functions of bone tissueBy Ivyrose, copyright Ivyrose Ltd, November 2003.
- Tissues of the human body By McGraw-Hill, Copyright ©1999 The McGraw-Hill Companies, unknown date.
- bone tissueBy unknown, About tissues, Mateusz Romanowski.
- Report on Bone Tissue YouTube, 29 March, 2009.
- Skeletal System:Bone Tissue YouTube, 2 December, 2009.