1. Skeletal System
By: Abby and Tessa

2. Terms Amp arthrosis- a slight movable joint
Diaphysis- the long straight shaft of a long bone
Diarthrosis- freely movable joint characterized by a joint cavity; also called a a synovial joint
Endochondral ossification- method of bone formation in which cartilage is replaced by bone
Epiphyseal plate- the cartilaginous plate between the epiphysis and diaphysis of a bone, responsible for the lengthwise growth of a long bone
Epiphysia- the end of a long bone

3. Five functions of the skeletal system
Bones support the soft organs of the body and support the body against the pull of gravity
Bones protect soft body parts such as the brain, spinal cord and heart
Bones work with muscles to produce movement
Bones store minerals, especially calcium
Most blood cell formation, hematopoiesis, occurs in red bone marrow

4. Compact and spongy bone on the basis of structural features
The microscopic unit of compact bone is the osteon or Haversian system
It consists of an osteonic canal, lamellae of matrix, osteocytes in lacunae, and canaliculi
In compact bone the osteons are packed closely together
Spongy bone is less dense
Consists of bone trabeculae around irregular cavities that contain red bone marrow
The trabeculae are organized to provide maximum strength to a bone

5. Different classifications of bones
Longer than they are wide; an example is the femur in the thigh
Short bones are roughly cube shaped; examples include bones in the wrist
flat bones have inner and outer tables of compact bone with a diploi of spongy bone in the middle; examples include the bones of the cranium
Irregular bones are primarily spongy bone with a thin layer of compact bone; examples include the vertebrae
Long bones have a diaphysis around a medullary cavity, with an epiphysis at each end. The epiphysis is covered by periosteum and lined with endosteum. All bones have surface markings that make each one unique

6. Bone development (osteogenesis) and growth
Osteoblasts, osteocytes, and osteoclasts are three types of cells involved in bone formation and remodeling.
Intramembranous ossification involved the replacement of connective tissue membranes by bone tissue. Flat bones of the skill develop this way.
Most bones develop by endochondral ossification. In this process, the bones first form as hyaline cartilage models, which are later replaced by bone.
Long bones increase in length at the cartilaginous epiphyseal plate. When the epiphyseal plate completely ossifies, increase in length is no longer possible.
Increase in diameter of long bones occurs by appositional growth. Osteoclasts break down old bone next to the medullary cavity at the same time osteoblasts form new bone on the surface.

7. Axial and appendicular skeletons
The axial skeleton together with the appendicular skeleton form the complete skeleton. Another definition of axial skeleton is the bones including the vertebrae, sacrum, ribs, and sternum.

8. Articulations
Synarthroses are immovable joints where the bones are held together by short fibers; structures are synarthrosis joints
Slightly movable joints are amphiarthroses. In this type of joint the bones are connected by hyaline cartilage or fibrocartilage. The symphysis pubis and intervertebral discs are examples of apmphiarthrotic joints.
Joints the are freely movable are diarthroses. The bones are held together by fibrous joint capsule that is lined with synovial membrane. these joints are sometimes called synovial joints. There are six types: gliding, condyloid, hinge, saddle pivot, and ball-and-socket.

9. Quiz Chapter recall AnswersG D F I H B A E J