Transcript Arthritis - PEER - Texas A&M University

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Arthritis
Partnership for Environmental Education and Rural Health
Texas A&M University
http://peer.tamu.edu
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Who knows what arthritis is?
• Do you know anyone that
has arthritis?
– Both humans and
animals can get
arthritis.
• What is arthritis?
– Arthritis is the
inflammation of joints.
• What are joints? Why do
we have them?
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Why do we have joints?
• What would your life be like
without joints?
– Try to write your name on a
piece of paper without
bending any joints.
– Try to jump up and down
without bending your knees.
• The joints that allow you to
move are called synovial joints.
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Parts of A Synovial Joint
Bone
Cartilage
Synovial Fluid
Joint Capsule
Ligament
• Let’s talk about each part
separately.
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Bone
• Bone is a living tissue.
• Bone is constantly remodeling itself… what does
that mean?
– Many cells exist in our bones
• Osteoclasts: Cells that ‘eat’ bone tissue
• Osteoblasts: Cells that ‘make’ bone tissue
• Osteocytes: Old osteoblasts surrounded by
“bone tissue”
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What makes up bone tissue?
• Inside your bone is inorganic material
containing calcium and other
elements.
• That means your bones are the
body’s calcium reserve.
• You body needs calcium to grow but
if it isn’t getting enough from food,
the osteoclasts will speed up and
chew away bone to release the
stored calcium faster than the
osteoblasts can store it.
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Joint Capsule
• A membrane or sac that surrounds the joint
• It helps hold all the parts of the joint together
• Consists of two membranes or layers:
– Fibrous Membrane: The outer layer which is thick
and tough and hold the joint together
– Synovial Membrane: The inner layer which
secretes the synovial fluid
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Cartilage
• A thin layer of cartilage lies on
the ends of the bones. It’s
smoothness prevents friction.
• Cartilage is also elastic and
compressible, allowing it to
absorb shock.
• Cartilage is a living tissue but
lacks blood vessels so the
nutrients it needs are
delivered by synovial fluid.
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Synovial Fluid
• Synovial fluid lubricates your
joints like oil helps a car.
• This prevents the cartilage
from wearing out too quickly
and allows for smooth
movement of the joint.
• Synovial fluid also
transports nutrients to the
cartilage.
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Ligaments
• Ligaments are tough,
fibrous bands that
connect bones to
bones.
• Many joints, like your
knee, require their
strong support to
function properly.
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Changes
• Each part of the joint has an important job to do. If
any part of a joint changes, it can make it difficult for
that joint to function properly.
• Some examples of bad changes include:
– Cartilage can become worn out and thin.
– Synovial fluid can become thinner, decreasing the
ability of the joint to slide freely.
– Ligaments can be torn or damaged by excessive
exercise or sudden trauma so that they fail to
support the joint.
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What is arthritis?
• Do you remember the
definition of arthritis?
• What are some things that
can cause inflammation?
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Infectious Arthritis
• Typically caused by bacteria.
• The bacteria may enter the body and travel
through the bloodstream to the joint, or bacteria
may be directly “injected” into a joint by trauma.
• The bacteria infect the synovial fluid, causing
inflammation, swelling, pain and fever.
• This type of arthritis can be treated by antibiotics
and other drugs. If treated promptly, patients
typically recover, although permanent damage
may be done to the joint.
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Infectious Arthritis
Bone
Cartilage
Synovial Fluid is infected
Joint Capsule is inflamed
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Infected vs. Normal Talus Joint
Thin bone
Normal bone
Thickened, inflamed joint capsule
Normal joint capsule
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Immune-Mediated Arthritis
• Occurs when the immune system targets the
body’s protein instead of germs.
• Why this happens is unknown.
• There is no cure for immune-mediated arthritis,
although there are treatments which reduce the
symptoms. Fortunately, this is a rare disease in
animals.
• Unfortunately, this disease occurs more
commonly in people and is called rheumatoid
arthritis.
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Immune-Mediated Arthritis
Bone is exposed and/or
damaged
Cartilage is destroyed
Synovial Fluid is thin
Joint Capsule is inflamed
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Osteoarthritis
• Osteoarthritis, also known as
degenerative joint disease, is
the most common type of
arthritis.
• Osteoarthritis occurs most to
older animals and humans.
• Over time, the cartilage in the
joint is broken down.
• As the cartilage is lost, the
bones are exposed and may rub
together, causing pain and more
damage. The joint may have
varying degrees of swelling, joint
scarring, and restricted motion.
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Osteoarthritis
Bone is worn away
Cartilage is worn away
Synovial Fluid with bone
fragments
Joint Capsule
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Degenerative Joint Disease of the Pastern
New bone
formation
Normal joint
space
Collapsed joint
space
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Who gets Arthritis?
Up
of every
5 dogs5may
be affected
by
Uptoto1 out
1 out
of every
dogs
may be
arthritis.
affected
by arthritis.
Similarly,
inAmerican
5 American
adults
Similarly, 1 1
in 5
adults have
been diagnosed
with arthritis.with
That’s
43
have
been diagnosed
arthritis.
million people!
That’s
43 million people!
Severe arthritis in horses can lead
to an inability to perform their jobs
or live comfortably. Many people
feel the same way!
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Why study Arthritis?
• Those with arthritis may have
difficulty performing tasks such as
walking, climbing stairs and
kneeling.
• Often times people with arthritis
have a hard time participating in
social activities and many end up
depressed.
• Try to imagine how your life would
be different if you had arthritis?
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Researching Arthritis
• Scientists are researching
arthritis to discover:
– tools that aid in
diagnosing arthritis
– treatments that work to
alleviate the symptoms of
arthritis.
– drugs that may help
prevent, slow down, or
reverse joint damage.
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Animals in Research
• Animal and human arthritis have
much in common. This allows
scientists to use animals to learn
about human arthritis.
• Dogs were used to develop and
study knee and hip replacements.
• Rodents studies were used to
understand rheumatoid arthritis.
• Today’s studies are providing
information that can help both
arthritic animals and humans in the
future!
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Questions?