Essay About Bone Classification And Example Of A Long Bone

The Skeletal System
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Chapter 7
I.Bone Structure
Bone Classification
4 Classes – Long, Short, flat and irregular
Example of a long bone- forearm and thigh bones.
Short Bones are shaped like cubes
Ex. Of short bones are in wrists and ankle bones
Flat bones are platelike structures
Ex of Flat bones are platelike structures
Irregular bones vary in size
Irregular bones vary in size
Examples of irregular bones are those of the vertebra and some facial bones
Round bones are also called sesamoid bones
They are small and modular and embedded in tendons
Example is the patella (kneecap)
Parts of a long bone
An expanded end of a long bone is an epiphysis
An epiphysis articulates with another bone
Articular Cartilage is located on the epiphysis
The shaft of a long bone is called a diaphysis
Periosteum functions t form and repair bone tissue
Periosteum is a tough, vascular, fibrous membrane covering the diaphysis of a bone
Processes provide sites for attachment of tendons or ligaments
The wall of the diaphysis is composed of compact bone
Compact bone has no gaps
Ephiphysis is composed of spongy bone
Spongy bone consists of bony plates called trabeculae
A bone is composed of spongy and compact bone
A canal called the medullary cavity runs through the diaphysis
The endosteum lines this cavity and spaces of the spongy bone
Endosteum contains bone forming cells
The tissue that fills the spaces of the bone is called marrow
The two forms of marrow are red and yellow marrow
Microscopic Structure
Intro
Bone cells are called osteocytes
Lacunae are tiny chambers that contain osteocytes
Lacunae form concentric that contain osteocytes
Osteocytes transport nutrients and wastes to and from the nearby cells
Cellular process of the osteocytes pass through the canaliculi
The intercellular matrix of bone is composed of collagen and inorganic salts
Compact Bones
An osteon is a cylinder shape unit of compact bone
The substance of compact bone is formed from many asteons cemented together
Each central canal contains blood vessels and nerves
Pereforating canals connect osteons
Pereforating canals contain layers veseels and nerves
Spongy Bone
Spongy bone is composed of osteocytes and intercellular material.
Unlike compact bone, the bone cells do not aggregate around central canals.
Instead the cells lie within the trabeculae
Bone cells get canaliculi that lead to the surface of trabeculae