General Anatomy
Synovial Joints
Single Hinge Joint
Usually comprises two bones
and moves in one plane, e.g.
elbow joint or
ankle
Ball and Socket Join
t
Rounded head on bone fits into a
cup shaped cavity on articulating
bone, e.g. hip joint or shoulder
Composite Hinge or Condyloid Joint
Two bones capable of moving in
More then one plane, e.g. wrist
The articulating bone surfaces are smooth
and covered with articular cartilage. In healthy
joints, the two surfaces of cartilage are in contact
with each other and are lubricated by a thin film of
synovial fluid. Synovial fluid nourishes and
lubricates the intra-articular surfaces. A sleeve of
strong fibrous tissue
–
the capsule
–
holds the
two bones together and surrounds the joint
The Muscular System
The principle characteristics of skeletal muscle are
contraction (shortening) and extension (lengthening). A
muscle consists of the belly or fleshy part of the muscle
and usually a tendon for attachment to bone. The muscle
must cross a joint in order to bring movement of that
particular joint.
Extension of one muscle is
usually brought about by
contraction of its opposing muscle. This is
the simple
basis of movement for example, if you flex the elbow
joint by contracting biceps brachii and brachialis, the
triceps, their antagonist will extend.
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