Changes

[[Image:Growth plate.jpg|right|thumb|250px|<small><center>Growth plate (Image sourced from Bristol Biomed Image Archive with permission)</center></small>]]

[[Image:Growth plate.jpg|right|thumb|250px|<small><center>Growth plate (Image sourced from Bristol Biomed Image Archive with permission)</center></small>]]

[[Image:Growth plate closer.jpg|right|thumb|250px|<small><center>Growth plate magnified (Image sourced from Bristol Biomed Image Archive with permission)</center></small>]]

[[Image:Growth plate closer.jpg|right|thumb|250px|<small><center>Growth plate magnified (Image sourced from Bristol Biomed Image Archive with permission)</center></small>]]

Bone comprises the structure of the skeletal system and provides lever arms for locomotion. Bone also plays important roles in maintaining mineral homeostasis, as well as providing the environment for [[Haematopoiesis - Overview|hematopoesis]] in [[Bone Marrow|marrow]].

Bone comprises the structure of the skeletal system and provides lever arms for locomotion. Bone also plays important roles in maintaining mineral homeostasis, as well as providing the environment for [[Haematopoiesis - Overview|hematopoesis]] in [[Bone Marrow|marrow]].

Found in the skull, pelvic girdle, and scapula. It expands in two directions, with a broad surface for attachment of large muscle masses and protection of underlying structures.

Found in the skull, pelvic girdle, and scapula. It expands in two directions, with a broad surface for attachment of large muscle masses and protection of underlying structures.

4. '''Sesamoid Bones'''

4. '''Irregular Bone'''

 

 

5. '''Sesamoid Bone'''

Eg. Patella and navicular bone. Found within tendons, where they change direction over prominences that would otherwise cause damage. They form '''synovial joints''' with major bones with which they are in contact. They also serve to displace tendon from the axis of the joint, increasing the leverage exerted by the muscle.

Eg. Patella and navicular bone. Found within tendons, where they change direction over prominences that would otherwise cause damage. They form '''synovial joints''' with major bones with which they are in contact. They also serve to displace tendon from the axis of the joint, increasing the leverage exerted by the muscle.

5. '''Splanchnic Bones'''

6. '''Splanchnic Bone'''

Develop in soft organs remote from skeletal connection, eg. '''os penis'''.  

Develop in soft organs remote from skeletal connection, eg. '''os penis'''.  

6. '''Pneumatic Bones'''

7. '''Pneumatic Bone'''

Excavated to contain air spaces, such as the skull in the instance of paranasal sinuses, and the post-cranial skeleton of birds.

Excavated to contain air spaces, such as the skull in the instance of paranasal sinuses, and the post-cranial skeleton of birds.

Osteoblasts, osteocytes, chondroblasts and chondrocytes are derived from the stromal fibroblastic system ('''osteoprogenitor cells'''). Osteoclasts are derived from the haematopoietic system.

Osteoblasts, osteocytes, chondroblasts and chondrocytes are derived from the stromal fibroblastic system ('''osteoprogenitor cells'''). Osteoclasts are derived from the haematopoietic system.

==Organization of Bone==

==Organisation of Bone==

The normal progression of bone is from woven bone to lamellar bone, even in pathology, except for [[Craniomandibular Osteopathy|canine craniomandibular osteopathy]] and [[Hypervitaminosis D|hypervitaminosis D]], where lamellar bone is replaced by woven bone.

The normal progression of bone is from woven bone to lamellar bone, even in pathology, except for [[Craniomandibular Osteopathy|canine craniomandibular osteopathy]] and [[Hypervitaminosis D|hypervitaminosis D]], where lamellar bone is replaced by woven bone.