a. Long Bones. The basic structure of a long bone is illustrated in figure 4-1
and discussed in paragraph 4-4. Example: femur.
b. Short Bones. The short bones, such as those of the wrist and feet, have a
thin layer of compact bone surrounding an inner mass of spongy bone.
Example: carpal bones.
c. Flat Bones. The flat bones are constructed with two plates of compact bone,
which enclose between them a layer of spongy bone. The spongy bone is richly
supplied with blood vessels and red marrow. Example: the cranial frontal bone.
d. Irregular Bones. The irregular bones are those that do not fit into the three
categories above. Example: a vertebra.
Section III. ARTHROLOGY--THE STUDY OF JOINTS (ARTICULATIONS)
4-7. DEFINITION
A joint, or articulation, is the location where two or more bones meet.
4-8. TYPES OF JOINTS
Joints are classified according to the kind of material holding the bones together
and the relative freedom and kind of motion at the particular joint.
a. Fibrous Joints. Varying degrees of motion, from none to some, are possible
in fibrous joints.
(1) Syndesmosis. When the bones are held together by FCT (fibrous
connective tissue), the joint is referred to as a syndesmosis.
SYN = together
DESMOS = fiber (a tying material)
Example: The inferior tibio-fibular joint.
(2) Suture. When the bones are quite close together with a minimum of FCT,
the joint is known as a suture. Example: the joints between the cranial bones.
b. Bony Joints. Should the bones be united by bony material, the joint is
referred to as a synosteosis.
SYN = together
OSTEO = bone
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