Download Joints and Articulations

Joints and Articulations
Anatomy & Physiology
Joints and
Articulations:
Junctions between
bones.
• Types/Categories
– Fibrous Joints
– Cartilaginous Joints
– Synovial Joints
Functions
• Bind parts of the skeleton.
• Allow for bone growth.
• Permit changes of skeleton
during childbirth.
• Allow for movement.
• Vary considerably in
structure and function.
• Classified based on degree
of movement.
AND/OR
• The type of tissue that
bonds the bones together.
Quick Fact
There are 230
joints/articulations
in the body!
Fibrous Joints
• Connect bones that are
very close to one another.
• A thin layer of connective
tissue joins the bones
together.
• No measurable
movement occurs at this
joint.
• Example: sutures
between bones of the
skull.
Cartilaginous Joints
• Use of hyaline
cartilage to connect
bone.
• Allows limited
movement.
• Absorbs shock.
• Example:
intervertebral discs.
Synovial Joints
•
•
•
•
Most joints fit into this category.
Permits free movement.
Structurally complex.
Ends of bones are covered with smooth cartilage = allows
for gliding and prevents bones from rubbing together.
• Surrounds a joint capsule filled with fluid to lubricate
joints.
• Some have flatened shock absorbing pads called
meniscus.
• Some have a bursae that allows for tendons to glide
smoothly over the joint.
Types of Synovial Joints
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•
•
•
•
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Ball-and-socket
Condyloid
Gliding
Hinge
Pivot
saddle
Ball-and-Socket
• Bone with a rounded
(ball-shaped) end that
articulates with a cupshaped cavity.
• WIDE range of motion
• Example: Shoulder and
Hip
Condyloid Joint
• Oval shaped bone
extension fits into a
shallow cavity.
• Can move in
different directions
but NOT rotate.
• Example: between
metacarpals (bone
of palm) and
phalanges (fingers).
Gliding Joint
• Articulations on an
almost flat plane.
• Allow for sliding or
twisting motion.
• Examples:
– Between carpal (wrist)
and tarsal (ankle) bones.
– Sternum and ribs.
– Sacrum and pelvis
Hinge Joint
• Convex surface of one
bone fits into concave
surface of another bone.
• Resembles the hinge of a
door.
• Examples:
– Joints of the phalanges
– Elbow
Pivot Joint
• Cylindrical surface of
one bone rotates in the
ring formed between
another bone and a
ligament.
• Permits rotation.
• Example:
– Radius and ulna
– Cervical vertebrae (neck)
and skull.
Saddle Joint
• BOTH bone surfaces
have both a concave
and convex surface.
• Bone fits like a puzzle
piece.
• Allows for a variety of
movement.
• Example: bones
between metacarpal
(hand) and thumb.
Special Considerations
• Arthritis:
inflammation of one or
more joints that results
in pain, swelling,
stiffness, and limited
movement
Special Considerations
• Arthrocentesis:
removal of fluid
from the joint
capsule to
alleviate pressure
and swelling.
Special Considerations
• Arthrodesis:
surgical union of a
joint; fusing two
or more bones
together
Surgical Union of Lumbar
(lower back) Vertebrae.
Meniscus Tears
• Meniscus are ligaments
found in the knee joint.
• They assist in stabilizing
the knee and limiting
motion that could cause
injury.
• Most injuries require
surgical correction.
• Becoming more common
in young athletes.