Transcript Chapter 9: Joints Anatomy 32 I. Articulations: bones are rigid structures but become moveable at the joint or articulations (Greek- arthro).

Chapter 9: Joints
Anatomy 32
I. Articulations: bones are rigid structures but become moveable at the joint or
articulations (Greek- arthro). Joints may occur as bone to bone, bone to
cartilage, or teeth to bone.
A. Classification of Joints- when classified by function the focus is placed
one the amount of movement. When classified by structure the focus is on
the tissue type that makes the joint. See table 9.1 pg 202for structural and
functional (mobility) characteristics.
1. synarthrosis- immovable
2. amphiarthrosis- slightly moveable
3. diarthroses-freely moveable
B. Fribrous joints- These are immobile or minutely mobile. Examples
are the joints of the cranium and the teeth. They are lined with
fibrous tissues (dense regular tissue).
1. Sutures- immoveable joints formed by skull bones and
connected by fibrous tissue.
2. Syndesmosisslightly
moveable but
no true
movement,
formed by a
ligament band
of fibrous tissue
• 3. Gomphosespeg in socket as
in the tooth and
gum containing a
small ligament
C. Cartilaginous joints-articulating bones are united by cartilage, no
joint cavity, not highly moveable.
1. Synchondroses- hyaline cartilage that unites bones as in the
ribs and sternum
2. Symphyses- fibrocartilage that unites
bones as in the pubic symphysis and
intervertebral bones.
D. Synovial joints-most moveable,
has fluid filled cavity with synovial
fluid, called diarthrosis.
1.Basic Features-hyaline
cartilage lines the ends of
bones, a cavity filled with fluid
called synovial fluid is
contained by a fibrous
capsule. It that has an outer
layer of dense irregular tissue
and joins the periosteum and
an inner layer of synovial
membrane (makes synovial
fluid). The synovial fluid is
viscous liquid that lubricates
the joint. Ligaments reinforce
the joint and nerves protect it
from over stretching.
Some joints also have a
meniscus (articular discs)
such as the knee joint.
Typical
Synovial
Joint
Synovial Joint with articulate disc (meniscus) in the middle
2. Function (mobility)- these joints are
highly lubricated to facilitate motion,
they routinely experience compression
and the fluid moves to accommodate
the pressure.
3. Joint stability- some joints have
articulating surfaces that stabilize the
joints such as the elbow and hip joint.
Ligaments strengthen the joint and
prevent it from moving incorrectly, they
are not as flexiable and capable of
reshaping.
4. Joint classification- the following
classifications are based on joint shape.
a. plane joints- flat articulating surfaces
that allow for short gliding movements
as in the wrist bones (intercarpals),
ankle bones (intertarsals), and vertebral
bones, no rotation around an axis (nonaxial).
b. hinge jointsmovement is
along one
plane (uniaxial)
such a hinged
door. Examples
are the elbow
and knee.
c. pivot jointsrounded end
of one bone
fits into the
other, also
uniaxial,
examples are
the radius
and ulna and
atlas and
dens.
d. condyloid
joints-(knuckle
like) oval like
shape of one
bone fits into an
oval bowl like
shape of the
other. It does not
rotate around its
axis but can
move sided to
side and back
and forth, it is
biaxial.
e. saddle joints- the
two ends fit into
one another as a
person sitting in a
saddle does.
They are biaxial
such as the
thumb joint (first
carpometacarpal
joint)
f. ball and
socket jointsspherical end
fits into round
socket, allows
movement in
multiple planes
of axis (triaxial)
such as the hip
and shoulder.
5. Selected synovial joint
a. temporomandibular joint- this is a synovial joint that
has an articular capsule, hinge like movement, and
anterior movement. Because it is so shallow it can be
easily dislocated.
Lateral Movement of TMJ
b. shoulder joint- less stable but more moveable, the glenoid fossa is
lined with fibrocartilage called the genoid labrum, ligaments support
limb weight and muscle tendons contribute to stability. This joint has
a rotator cuff formed by tendons. It also has bursa and tendon
sheaths.
c. elbow jointstable hinge
joint,
ligaments
stabilize and
prevent
lateral/medial
movements.
Lateral View
Medial View
d. hip joint- stable ball-and-socket joint, wide range of motion but less
than shoulder joint due to more depth. Also has a rim of
fibrocartilage called acetabular labrum that prevents the femur from
slipping. Capsular ligaments provide stability.
Anterior View
Posterior View
Knee Joint Information
e. knee joint- largest and most complex, it includes the
femur, tibia, and patella. It contains:
1) several bursae,
2) lateral and medial menisci (fibrocartilage rings) that
guide the condyles.
3) three anterior ligaments originating from patella to
tibia: patellar ligament, medial and lateral ligament
4) fibular and tibial collateral ligaments support the joint
capsule
5) anterior and posterior cruciate- attaches across joint
internally
6) ligaments from fibula to femur anterior or posterior
Anterior view of
the knee.
• A lateral blow
can cause the
femur and tibia
to separate
tearing several
ligaments that
are attached to
each other.
• Pg. 234
E. Joint disorders
1. Sprain-stretch or torn ligaments
2. Dislocation (luxation)- bones are forced out of alignment and must
be reduced (returned to original location). Subluxation is a partial
dislocation.
3. Torn cartilage- when it is subjected to high compression and
tension, example: meniscus tearing. It does not heal itself thus
broken fragments are removed by arthroscopic surgery.
4. bursitis/tendonitis- swelling of the bursa or tendon sheaths
5. arthritis- inflammation or degeneration of the joints.
a. osteoarthiritis- related to aging, the joints wear out. Use of
joint causes enzyme that breakdown the cartilage to
breakdown, occurs more often in misaligned joints may form
bone spurs. It happens often in non-synovial joints.
Deformity caused by rheumatoid
arthritis
b. rheumatoid arthiritis- it is an autoimmune disease in which the
immune system attacks the cartilage causing inflammation and
muscle weakness. It affect women more than man and joints
bilaterally and simultaneously.
c. gouty arthiritis- uric acid accumulates in joints causing
inflammation at the joints. It affects men more than women and if
untreated can lead to fused bones.
d. Lyme disease-bacteria transmitted by tick bites causes joint
inflammation and many other symptoms. It is difficult to diagnose
and treat.
F. Joints throughout life
Synovial joints originate from mesenchyme, joints are modified after
use by movement and use- more active joints are more massive.
Epiphyseal plates are vulnerable during youth. With aging the joint
become arthritic although this can be delayed with exercise.
Good luck preparing for the test!!!!!
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Movement of synovial jointsAngular movements- increase or decrease the joint angle and bring limb
towards or away
1. Flexion- reduces joint angle (bending at the joint) brings bones closer,
usually in the sagittal plane
2. Extension- increases joint angle (straightening joint) brings bones further
apart
3. Hyperextension- increasing joint angle beyond its normal range
4. Abduction- moving the joint such that limbs are moved away from the
body
5. Adduction- moving the joint such that limbs are moved toward the body
6. Circumduction- a combination of flexion, extension, abduction, and
adduction. (making a circle)
7. Rotation-movement of bone along its own long axis only three areas can
do this: atlas and axis, shoulder joint, hip joint. Medial rotation- movement
towards the median . Lateral rotation- movement away from the median
8. Supination- lateral radial rotation to turn palm anteriorly
9. Pronation-medial radial rotation to turn palm posteriorly
10. Dorsiflexion-lifting foot to superior side of foot approaches shin
11. Plantar flexion-depressing the foot (pointing toes)
12. Inversion-turn sole of foot medially
13. Eversion-turn sole of foot laterally
14. Protraction and Retraction- non angular movement, forward= protaction
back=retraction
15. Elevation- moving body part superiorly
16. Depression- moving body part inferiorly
1. Flexion- reduces joint angle (bending at the joint) brings
bones closer, usually in the sagittal plane
2. Extension- increases joint angle (straightening joint) brings
bones further apart
3. Hyperextension- increasing joint angle beyond its normal
range
1. Flexion- reduces joint angle (bending at the
joint) brings bones closer, usually in the sagittal
plane
2. Extension- increases joint angle (straightening
joint) brings bones further apart
3. Hyperextension- increasing joint angle beyond
its normal range
1. Flexion- reduces joint angle (bending at the joint) brings bones
closer, usually in the sagittal plane
2. Extension- increases joint angle (straightening joint) brings bones
further apart
3. Hyperextension- increasing joint angle beyond its normal range
4. Abduction- moving the joint such that limbs are moved away from the body
5. Adduction- moving the joint such that limbs are moved toward the body
6. Circumduction- a combination of flexion, extension, abduction, and adduction.
(making a circle)
7. Rotation-movement of bone along its own long axis only three areas can do
this: atlas and axis, shoulder joint, hip joint. Medial rotation- movement
towards the median . Lateral rotation- movement away from the median
8. Supination- lateral radial rotation to turn palm anteriorly
9. Pronation-medial radial rotation to turn palm posteriorly
10. Dorsiflexion-lifting foot to superior side of foot approaches shin
11. Plantar flexion-depressing the foot (pointing toes)
12. Inversion-turn sole of foot medially
13. Eversion-turn sole of foot laterally
14. Protraction and Retraction- non angular movement,
forward= protaction back=retraction
15. Elevation- moving body part superiorly
16. Depression- moving body part inferiorly