Page 2100 - Saunders Comprehensive Review For NCLEX-RN

a. The length of bone growth results from
ossification of the epiphyseal cartilage
at the ends of bones; bone growth
stops between the ages of 18 and 25
years.
b. The width of bone growth results from
the activity of osteoblasts; it occurs
throughout life but slows down with
aging.

As aging occurs, bone resorption

accelerates, decreasing bone mass and
predisposing the client to injury.
C. Types of joints (Table 60-1)
1. Characteristics of joints
a. Allow movement between bones
b. Formed where 2 bones join
c. Surfaces are covered with cartilage.
d. Enclosed in a capsule (synovial joints)
e. Contain a cavity filled with synovial
fluid (synovial joints)
f. Ligaments hold the bone and joint in the
correct position.
g. Articulation is the meeting point of 2 or
more bones.
2. Synovial fluid
a. Found in the synovial joint capsule
b. Formed by the synovial membrane,
which lines the joint capsule
c. Lubricates the cartilage
d. Provides a cushion against shocks
D. Muscles
1. Characteristics of muscles
a. Made up of bundles of muscle fibers
b. Provide the force to move bones
c. Assist in maintaining posture
d. Assist with heat production
2. Process of contraction and relaxation
a. Muscle contraction and relaxation
require large amounts of adenosine
triphosphate.
b. Contraction also requires calcium,
which functions as a catalyst.
c. Acetylcholine released by the motor end
plate of the motor neuron initiates an
action potential.
d. Acetylcholine is then destroyed by

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