Essentials of Human Anatomy
The Skeletal System 4
Joints of the Skeletal System
Chapter 5
Dr Fadel Naim
Ass. Prof. Faculty of Medicine
IUG
1
Joints of the Skeletal
System
• Articulations
• Functional junctions between bones
• Bind parts of skeletal system together
• Make bone growth possible
• Permit parts of the skeleton to change shape during
childbirth
• Enable body to move in response to skeletal muscle
contraction
Naming of Joints
• Usually derived from the names of the
articulating bones.
Classification of Joints
• Fibrous Joints
• dense connective tissues connect
bones
• between bones in close contact
• Cartilaginous Joints
• hyaline cartilage or fibrocartilage
connect bones
• Synovial Joints
• most complex
• allow free movement
• synarthrotic
• immovable
• amphiarthrotic
• slightly movable
• diarthrotic
• freely movable
Fibrous Joints
3 Types
• Syndesmosis
• Suture
• Gomphosis
Syndesmosis
•a sheet or bundle of
fibrous tissue connects
bones
• amphiarthrotic
• lies between tibia
and fibula
Fibrous Joints
Suture
• between flat bones
• synarthrotic
• thin layer of connective
tissue connects bones
Gomphosis
• cone-shaped bony
process in a socket
• tooth in jawbone
• synarthrotic
Cartilaginous Joints
2 Types
• Synchondrosis
• Symphysis
Synchondrosis
• bands of hyaline cartilage
unite bones
• epiphyseal plate
(temporary)
• between manubrium and
first rib
• synarthrotic
Cartilaginous Joints
Symphysis
• pad of fibrocartilage between bones
• pubis symphysis
• joint between bodies of adjacent vertebrae
• amphiarthrotic
General Anatomy of Synovial Joints
• Basic features:
– articular capsule
– joint cavity
– synovial fluid
– articular cartilage
– ligaments
– nerves
– blood vessels
General Anatomy of Synovial Joints
– Accessory Structures
• Bursae
– fibrous, saclike structure that contains synovial fluid
and is lined by a synovial membrane
• Fatpads
– often distributed along the periphery of a synovial joint
– act as packing material and provide some protection
for the joint
– fill the spaces that form when bones move and the
joint cavity changes shape
• Tendons
– attaches a muscle to a bone
– help stabilize joints
Types of Synovial Joints
• Classified by the shapes of their articulating
surfaces
• Types of movement they allow
– uniaxial if the bone moves in just one
plane
– biaxial if the bone moves in two planes
– multiaxial (or triaxial) if the bone moves
in multiple planes
Types of Synovial Joints
• From least movable to most freely movable,
the six specific types of synovial joints
are:
• planar (gliding) joints
• hinge joints
• pivot joints
• condyloid (ellipsoid) joints
• saddle joints
• ball-and-socket joints
Types of Synovial Joints
Ball-and-Socket Joint
• hip
• shoulder
Condyloid Joint
• between metacarpals
and phalanges
Types of Synovial Joints
Gliding Joint
• between carpals
• between tarsals
Hinge Joint
• elbow
• between phalanges
Types of Synovial Joints
Pivot Joint
• between proximal
ends of radius and
ulna
Saddle Joint
• between carpal and
metacarpal of thumb
Types of Synovial Joints
Mobility and Stability in Joints
• Motion permitted ranges from none to various extensive
motions.
• Structure determines both its mobility and its stability.
– more mobile = less stable
Types of Joint Movements
• abduction/adduction
• dorsiflexion/plantarflexion
• flexion/extension/hyperextension
Types of Joint Movements
• rotation/circumduction
• supination/pronation
Types of Joint Movements
• eversion/inversion
• protraction/retraction
• elevation/depression
Shoulder Joint
• ball-and-socket
• head of humerus
• glenoid cavity of scapula
• loose joint capsule
• bursae
• ligaments prevent
displacement
• very wide range of
movement
Shoulder Joint
Elbow Joint
• hinge joint
• trochlea of humerus
• trochlear notch of ulna
• gliding joint
• capitulum of humerus
• head of radius
• flexion and extension
• many reinforcing ligaments
• stable joint
Elbow Joint
Hip Joint
• ball-and-socket joint
• head of femur
• acetabulum of coxa
• heavy joint capsule
• many reinforcing ligaments
• less freedom of movement
than shoulder joint
Hip Joint
Knee Joint
• largest joint
• most complex
• medial and lateral condyles of distal
end of femur
• medial and lateral condyles of
proximal end of tibia
• femur articulates anteriorly with
patella
• modified hinge joint
• flexion/extension/little rotation
• strengthened by many ligaments and
tendons
• menisci separate femur and tibia
• bursae
Knee Joint
Life-Span Changes
• Joint stiffness is an early sign of aging
•Fibrous joints first to change; can strengthen over a
lifetime
• Changes in symphysis joints of vertebral column
diminish flexibility and decrease height
• Synovial joints lose elasticity
• Disuse hampers the blood supply
• Activity and exercise can keep joints functional
longer
Cycle of Life: Articulations
• Bone development and the sequence of
ossification between birth and skeletal maturity
affect joints
– Fontanels between cranial bones disappear
– Epiphysial plates ossify at maturity
• Older adults
– ROM decreases
– Changes in gait occur
• Skeletal diseases manifest as joint problems
– Abnormal bone growth (lipping)—influences joint motion
– Disease conditions can be associated with specific
developmental periods
Clinical Application
Joint Disorders
Sprains
• damage to cartilage, ligaments, or tendons associated
with joints
• forceful twisting of joint
Bursitis
• inflammation of a bursa
• overuse of a joint
Tendonitis
•An inflammation of the tendon
•Caused by excessive use.
Arthritis
• A group of inflammatory or degenerative diseases of
joints that occur in various forms.
– swelling of the joint
– pain
– stiffness
• Most prevalent crippling disease in the United States.
– gouty arthritis
– osteoarthritis :A condition which results when the articular cartilage is
enlarged or as deteriorated this results is a decrease in the range of
movement of the joint.
– rheumatoid arthritis: An inflammation of a joint which is the result of an
autoimmune disease
THE END