Covering, Support, and Movement of the Body
Arthritis is joint inﬂammation or degeneration accompanied
by stiﬀness, pain, and swelling. Acute forms generally result
from bacterial infection. Chronic forms include osteoarthritis,
rheumatoid arthritis, and gouty arthritis.
Osteoarthritis is a degenerative condition most common in the
aged. Spine, knees, hips, knuckles, and ﬁngers are most aﬀected.
Rheumatoid arthritis, the most crippling arthritis, is an
autoimmune disease involving severe inﬂammation of the joints.
Gouty arthritis, or gout, is joint inﬂammation caused by the
deposit of urate salts in soF joint tissues.
Lyme disease is an infectious disease caused by the bite of a tick
infected with spirochete bacteria.
Developmental Aspects of Joints
Joints form from mesenchyme and in tandem with bone
development in the embryo.
Excluding traumatic injury, joints usually function well until
late middle age, at which time symptoms of connective tissue
stiﬀening and osteoarthritis begin to appear. Prudent exercise
delays these eﬀects, whereas excessive exercise promotes the early
onset of arthritis.
weight bearing. Its articular surfaces are deep and secure. Its
capsule is heavy and strongly reinforced by ligaments.
Te temporomandibular joint is formed by (1) the condylar
process of the mandible and (2) the mandibular fossa and
articular tubercle of the temporal bone. Tis joint allows both
a hingelike opening and closing of the mouth and an anterior
gliding of the mandible. It oFen dislocates anteriorly and exhibits
a number of ±MJ disorders.
Homeostatic Imbalances of Joints
Common Joint Injuries
Cartilage injuries, particularly of the knee, are common in contact
sports and may result from excessive compression and shear
stress. Te avascular cartilage is unable to repair itself.
Sprains involve stretching or tearing of joint ligaments. Because
ligaments are poorly vascularized, healing is slow.
Dislocations involve displacement of the articular surfaces of
bones. Tey must be reduced.
Inﬂammatory and Degenerative Conditions
Bursitis and tendonitis are inﬂammations of a bursa and a tendon
(Some questions have more than one correct answer. Select the best
answer or answers from the choices given.)
Match the key terms to the appropriate descriptions.
exhibit a joint cavity
types are sutures and syndesmoses
bones connected by collagen ﬁbers
types include synchondroses and symphyses
all are diarthrotic
many are amphiarthrotic
bones connected by a disc of hyaline cartilage or
nearly all are synarthrotic
shoulder, hip, jaw, and elbow joints
²reely movable joints are
Anatomical characteristics shared by all synovial joints include
a joint cavity,
presence of ﬁbrocartilage.
²actors that inﬂuence the stability of a synovial joint include
shape of articular surfaces,
presence of strong reinforcing
tone of surrounding muscles,
all of these.
Te description “Articular surfaces deep and secure; capsule
heavily reinforced by ligaments and muscle tendons; extremely
stable joint” best describes
the elbow joint,
the hip joint,
the knee joint,
the shoulder joint.
twisting of the ankle,
displacement of a bone,
immobility of a joint
due to fusion of its articular surfaces.
An autoimmune disorder in which joints are aﬀected bilaterally
and which involves pannus formation and gradual joint
Short Answer Essay Questions
Discuss the relative value (to body homeostasis) of immovable,
slightly movable, and freely movable joints.
Compare the structure, function, and common body locations of
bursae and tendon sheaths.
Joint movements may be nonaxial, uniaxial, biaxial, or multiaxial.
Deﬁne what each of these terms means.
Compare and contrast the paired movements of ﬂexion and
extension with adduction and abduction.
How does rotation diﬀer from circumduction?
Name two types of uniaxial, biaxial, and multiaxial joints.
What is the speciﬁc role of the menisci of the knee? Of the
anterior and posterior cruciate ligaments?
Te knee has been called “a beauty and a beast.” Provide several
reasons that might explain the negative (beast) part of this
Why are sprains and cartilage injuries a particular problem?
List the functions of the following elements of a synovial
joint: ﬁbrous layer of the capsule, synovial ﬂuid, articular
and Clinical Application
Sophie worked cleaning homes for 30 years so she could send her
two children to college. Several times, she had been forced to call
her employers to tell them she could not come in to work because
one of her kneecaps was swollen and painful. What is Sophie’s
condition, and what probably caused it?