functions of the skeleton 1. protection protect vital and delicate soft-tissue structures from...
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Functions of the Skeleton1. Protection
Protect vital and delicate soft-tissue structures from injury. Skull and the rib cage.
2. SupportThe skeletal system provides the support
necessary to safely maintain an upright posture.
3. MovementBones serve as points of attachment for
muscles.As muscles contract, bones act as levers.Joints serve as pivot points that allow actual
movement.
Classifications of BonesDivided into five groups.
1. Long bones2. Short bones3. Flat bones4. Irregular bones5. Sesamoid bones
Wrist and ankleTend to be cube shaped and are generally
found in areas which only very limited motion is required.
Principle function is to provide strength.
Consist of parallel, platelike layers of hard or compact bone .
Provide large areas for muscle attachment.Protection.
Bones that have obvious peculiarities in their shape are placed in this classification.
Unique in appearance and function.SpinePelvisOssicles of the ear.
Small and rounded and triangular bones usually develop within the substance of tendons and fascial tissue.
Found adjacent to joints.Named after their resemblance to sesame
seeds.
Features of a Typical BoneEvery bone in the skeleton is a unique organ
– a distinct structural unit.
Long bones uniformly possess many of the features of bones in general.
Organization of the SkeletonThe 206 bones of the adult skeleton are
grouped into two subdivisions:
1. Axial Skeleton (80) bones. 6 tiny middle ear bones 74 bones that form the upright axis of the body
Skull, vertebral column, and thorax (sternum and ribs)
Appendicular skeleton (126 bones)Form the appendages and the girdles that
attach them to the axial skeleton.Shoulder girdles, arms, wrists, hands, hip
girdles, legs, ankles, and feet.
Differences Between Male and Female SkeletonsMale skeleton is larger and heavier.The male pelvis is deep and funnel-shaped,
the female pelvis is shallow, broad, and flaring.
Bones of the male lower extremity tend to be longer.
Classification of JointsClassified into three major groups or types.1. Synarthroses (immovable joints)2. Amphiarthroses (slightly moveable joints)3. Diarthroses (freely movable joints)
DiarthrosesOften called synovial joints.
Characterized by the presence of a closed cavity between the bones that make up the joint.
Functionally the most important.
Most complex structure and are most vulnerable to injury.