The Joints of the Skeleton
System
Primarily Synovial Joints
JOINTS
Joints or articulations are functional
junction between bones…or the site where
two bones meet.
 They bind parts of the skeletal system,
make possible bone growth, permit parts
of the skeleton to change shape during
childbirth, and enable the body to move in
response to skeletal muscle contractions.

JOINTS

Joints can also
be grouped
according to the
degree of
movement
possible at the
bony junction.
Synarthrotic –
Immovable joints
 AmphiarthroticSlightly moveable
 DiarthroticFreely movable.

JOINTS


Joints vary
considerably in
structure and function
However, they can be
classified by the type
of tissue that binds
the bones at each
junction.
Three general
groups are:
 Fibrous joints
 Cartilaginous Joints
 Synovial Joints

Fibrous Joints
Fibrous Joints- are so named
because of the fibrous tissue that
holds them together
 In a fibrous joint there is no joint
cavity present.
 Most fibrous joints are immovable.
 They lie between bones that closely
contact one another.

Fibrous Joints




Three types of
fibrous joints:
Syndesmosis-Distal
end of the tibia and
fibula
Suture- only
between flat bones
in the skull
Gomphosis- root of
a tooth to the
jawbone
Cartilaginous Joints
Cartilaginous Joints- Hyaline cartilage or
fibrocartilage connect the bones of this
joint.
 Two Types are:
 Synchondrosis (the articulation between
the first rib and the manubrum)
 Symphysis (the smyphiysis pubis in the
pelvis)

Cartilaginous Joints
Cartilaginous Joints
SYNOVIAL JOINTS


Most joints of the skeletal system are synovial
joints, and because they allow free movement,
they are diarthrotic.
These joints are more complex structurally than
fibrous or cartilaginous joints.
SYNOVIAL JOINTS

Synovial Joint have five distinguishing
features.
1. Articular Cartilage is present at the ends of the
opposing bones
2. Joint Cavity (synovial) is present. This is really just
potential space that contains fluid.
3. Articular capsule (aka joint capsule). This encloses
the joint cavity.
4. Synovial Fluid- is present and occupies the space
within the joint capsule.
5. Reinforcing Ligaments – Synovial joints are
reinforced and strengthened by a number of
bandlike ligaments.
Bursae and Tendon Sheaths

Not strictly
associated with
synovial joints but
are often found
associated with
them.


Bursae are flattened
fibrous sacs lined with
synovial membrane
and containing a thin
film of synovial fluid.
Tendon Sheath is
essentially an
elongated bursa that
wraps completely
around a tendon
subjected to friction.
Bursae and Tendon Sheaths
SYNOVIAL JOINTS
6 Types
Ball and Socket

The Ball and Socket
joint consists of a
bone with a globular
or slightly eggshaped head the
articulates with the
cup-shaped cavity of
another.


Such joint allows a
wider range of motion
than does any other
kind.
Permitting
movements in all
planes, as well as
rotation movement
around a central axis.
Ball and Socket

Examples: Hip
and Shoulder
contain joints
of this type.
Condyloid Joint

Condyloid joint,
the oval condyle
of one bone fits
into the elliptical
cavity of another
bones.

This type of
joints permits a
variety of
movements in
different planes;
rotational
movement,
however,is NOT
possible.
Condyloid Joint
Condyloid Joint
exists between the
metacarpals and
the phalanges.
 And the
radiocarpal
(wrist) joints.

GLIDING JOINTS
(aka Plane Joints)

The articulating
surfaces of
gliding joints
are nearly flat
or slightly
curved.

These joints
allow sliding or
back-and-forth
motion and
twisting
movements.
GLIDING JOINTS
(aka Plane Joints)



Most of the joints
within the wrist and
ankle.
The articular processes
of adjacent vertebrae.
Joints formed by ribs 27 connecting the
sternum are also gliding
joints.
HINGE JOINT

In a hinge joint,
the convex
surface of one
bone fits into the
concave surface
of another.

Such a joint
resembles the
hinge of a door
in that it permits
movement in
one plane only.
HINGE JOINT

The elbow
and the joints
of the
phalanges.
PIVOT JOINT

In a pivot joint, the
cylindrical surface
on one bone
rotates within a
ring formed on
bone and fibrous
tissue of a
ligament.

Movement at
such a joint is
limited to
rotation around a
central axis.
PIVOT JOINT
The joint
between the
proximal ends of
the radius and
the ulna.
 A pivot joint
functions in the
neck as the head
turns from side
to side.

SADDLE JOINT

A saddle joint
forms between
bones whose
articulating
surfaces have both
concave and
convex regions.
The surface on one
bone fits the
complementary
surface of another.

This physical
relationship
permits a variety
of movements,
mainly in two
planes.
SADDLE JOINT

The joint
between the
carpal and the
metacarpal of
the thumb.
Movements Allowed by
Synovial Joints
Every skeletal muscle of the body is
attached to bone or other connective
tissue structures at no fewer than
two points
 The muscles origin is attached to
the immovable ( or less moveable )
bone.
 Its other end, the insertion, is
attached to the moveable bone.

Gliding Movements
AKA as translation, are the simplest
joint movements.
 Back and forth or side to side!

Angular Movements

Angular Movements increase or
decrease an angle between two
bones.
Flexion


Flexion- Bending
movement, that
decreases the angel of
the joint and bring the
articulating bones
closer together
Ex: bending the head
forward on the chest;
bending the knee from
a straight to an angled
position.
Extension


Extensionopposite of flexion,
that increases the
angel of the joint
and brings the
articulating bones
farther apart.
Ex: Straightening
a flexed
Hyperextension

HyperextensionBending part of the
body past its
straight upright
position.
Abduction/Adduction


AdductionMoving a part
toward the midline.
(returning into the
side of the body)
AbductionMoving a part
away from the
body.
Circumduction



Circumduction- Moving a limb so
that it describes a
cone in space.
The quickest way
to exercise the
many muscles that
move the hip and
shoulder ball and
socket joints.
.
Dorsiflexion and Plantar Flexion
of the Foot

Dorsiflexion- Lifting the foot so
that its superior surface approaches
the shin.
Dorsiflexion and Plantar Flexion
of the Foot

Plantar Flexion- depressing the
foot or pointing the toes.
Special Movements
Some movements do NOT fit into a
specific category and occur only at a
few joints.
 They are illustrated in the next few
slides.

Rotation



Rotation- The
turning of a bone
around its own
long axis.
It is the only
movement allowed
between the C1
and C2 vertebra
Common at the hip
and shoulder joint.
Supination and Pronation
Both of these refer to movement of
the radius around the ulna.
 Supination meaning “turning
backwards”..rotate the arm so the
palm is facing anteriorly
 Pronation- meaning turning
forward…rotate the arm so the palm
is facing posteriorly.

Supination and Pronation
Inversion and Eversion



Both of these refer
to special
movement of the
foot.
Inversion- the
sole of the foot
turns medially
Eversion- the
sole faces
laterally..
Protraction and Retraction



Nonangular anterior
and posterior
movements in a
transverse plane.
The mandible is
protracted when you
jut out your jaw.
And retracted when
you move it back to
its original position.
Elevation and Depression



Elevate- lifting a
body part superiorly.
(shrugging your
shoulders)
Depression is moving
the elevated part
inferiorly.
Chewing your food is
alternately both
elevation and
depression.
Opposition


Opposition –
found in the saddle
joint between the
metacarpal and the
carpals.
This is the action
taken when you
touch your thumb
to the tips of the
other fingers on
the same hand.
What type of movements do
we have here?
1. Abduction at the
right hip,
adduction at
both shoulders.
What type of movements do
we have here?
• Flexion at the
left knee
• Flexion at the
left hip,
• Extension at
the
right hip,
• Extension at
the right knee.
What type of movements do
we have here?
• Flexion at both hips
• Abduction at the
shoulders
• Extension at the elbows
• Extension at both knees.
What type of movements do
we have here?
•
Flexion at both
hips,
• Flexion at both
knees,
• Extension at both
elbows.
What type of movements do
we have here?
1. Rotation / extension at
the hips.
What type of movements do
we have here?
• Flexion at both
knees,
• Adduction at the
shoulders
What type of movements do
we have here?
Abduction at both hips.
What type of movements do
we have here?
1. Flexion / rotation at the
shoulder.
The Knee
The knee joint is the largest and
most complex joint in the body.
 It allows flexion, extension, and
some rotation.
 It is actually composed of 3 separate
joints.

The Knee
Be able to identify the ACL, PCL,
meniscus, all three bursa sacs, and
the femur, tibia, and patella.
 YOU NEED TO DRAW COLOR AND
LABEL THE KNEE…you will have to
label this on a test. Please add this
to the back side of your first
drawing. Due at the end of class
today!!!
 Pg 266 (a)

The Knee
You need to know the following
joints.


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


What type of joints will you find here? Both
structural and functional (or movements)
Skull
Intervertebral
Sternocostal (ribs 1-7)
Shoulder
Elbow
Radioulnar (proximal and distal)
Wrist
Intercarpal
Carpometacarpal
You need to know the following
joints.



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

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


What type of joints will you find here? Both
structural and functional (or movements)
Knuckle
Finger
Pubic Symphysis
Hip
Knee
Tibiofibular
Ankle
Intertarsal
Tarsometatarsal
Metatarsolphalangeal
When your Joints hurt!!
Usually we don’t think about joints
until we have a problem and they
begin to hurt us.
 This can be caused by trauma,
inflammation, and/or arthritis.

Sprains!!




Sprain- the ligaments
reinforcing a joint are
stretched or torn.
Lumbar region of the
spine, ankle and knee are
common.
Ligaments heal very slowly
because they are poorly
vascularized.
Cartilage is avascular and
it rarely can obtain
sufficient nourishment to
repair itself. It usually
stays torn.
Sprains!!
Cartilage fragments can interfere
with joint function by causing joints
to lock or bind. So most sports
physicians recommend that the
central par of a damaged cartilage be
removed.
 This can be done by arthroscopic
surgery.

Arthroscopic surgery.
Dislocation



A dislocation occurs
when bones are forced
out of alignment.
Usually accompanies
sprains, inflammation,
and joint
immobilization
Repeat dislocation of
the same joint are
common because the
initial dislocation
stretches the joint
capsule and
ligaments.
Bursitis/Tendonitis



Bursitis is
inflammation of a
bursa and is usually
caused by a blow or
friction
Tendonitis is
inflammation of
tendon sheaths,
typically caused by
overuse.
Treatments for both
include…rest, ice, and
anti-inflammatory
drugs.
Osteoarthritis





It is the most common
chronic arthritis
It is chronic
degenerative, often
called “wear and tear”
arthritis.
Normal in the aging
process
The normal joint use
prompts the release of
enzymes that break
down articular
cartilage.
The result is softened,
roughened, pitted,
and eroded articular
cartilages.
Rheumatoid Arthritis





It is not as common but still effects millions.
Effect women more than men, usually between the
ages of 40-50
In early stages joint tenderness and stiffness are
common
Usually effects small joints like wrist, ankles, fingers,
and feet.
Has both flare ups and remissions
Rheumatoid Arthritis



RA- is an autoimmune
disease- a disorder in
which the body’s
immune system
attacks its own tissue.
Unknown cause but
suspects include
bacterium and
viruses.
Synovial fluid can
increase
Gouty
Arthritis







The symptoms of gout
are almost always acute
and sudden, happening
often at night with no
warning. Symptoms in
the affected joints may
include:
Intense pain
Swelling
Tenderness
Redness
One of the oldest known diseases, gout was once
considered "the disease of kings" because it was associated
with those wealthy enough to overindulge in rich food and
drink.
In fact gout is a complex disorder that can affect anyone
and does affect more than 2 million Americans.



Gout is caused by high
blood levels of uric
acid, a waste formed
from the breakdown of
purines.
If the body produces
too much or eliminates
too little uric acid, it
builds up and forms
needle-like crystals in
a joint or the
surrounding tissue,
At the right is a
photograph of crystals
of monosodiumurate,
which cause gout.
They are identified by
their shape and
physical properties
when seen under a
microscope
Gouty Arthritis



Seen more often in
men than women
Genetic factors are
definitely implicated.
Excess alcohol can
promote excess uric
acid..