Biology 30S (11-3) - 2009/2010

The Skeletal System

Last bio class we watched another great movie. But just incase you were not listening to Mike Dowling, ill try and review the important parts.

-The Skeletal System serves many important functions. It allows are bodys to move, in addition to supporting, protecting, and storing minerals.



- Blood cells are produced by the marrow located in some bones. An average of 2.6 million red blood cells are produced each second by the bone marrow to replace those worn out and destroyed by the liver.



-Bones serve as a storage area for minerals such as calcium, minerals, salts, fats and phosphorus. When an excess is present in the blood, buildup will occur within the bones. When the supply of these minerals within the blood is low, it will be withdrawn from the bones to replenish the supply.



Types of Bone:


Long bones- are longer than they are wide and work as levers. Ex.) Femur

Short bones- are short and spongy. Found in the wrists and ankles.

Flat bones- are thin and have broad surfaces for protection of organs and attachment of muscles.

Irregular bones- are all others that do not fall into the previous categories. They have varied shapes and sizes.

Divisions of the Skeleton

The human skeleton is divided into two distinct parts:

- Axial Skeleton
- Appendicular Skeleton

- The axial skeleton consists of bones that form the axis of the body and support and protect the organs of the head, neck, and trunk. Ex.) The Skull, Sternum, and Ribs.
-The appendicular skeleton is composed of bones that anchor the appendages to the axial skeleton. Ex.) The Upper and Lower Extremities.

Bones

Human Skeletons have 206 bones. Im not going to tell you about all of them but there is a nice picture at the top of the page for you. =)

Joint System:

Functional classification of joints (based on the amount of movement allowed at the joint)

1)Synarthroses: immovable joints

2)Amphiarthroses: slightly movable joints

3)Diarthroses: freely movable joints

Structural classification of joints (based on the material binding the bones together)

1)Fibrous: the articulating bones are held together by fibrous connective tissue.

2)Cartilaginous: the articulating bones are held together by cartilage.

3)Synovial: ligaments aid in supporting the articulating bones. Synovial Joints include:

Gliding joints, Hinge joints, Pivot joints, Saddle joints, ect.

Thats all for now! Have fun reviewing!

=)