6. FIBROUS JOINTS
• Fibrous joints are defined as the joints in which the bones are
connected by fibrous tissue.
• They are called fixed or immovable joints as they do not allow
any movement between the bones.
• They do not have a joint cavity, and the fibrous tissue which
connects the bones is made up of collage fibres.
7. These can be grouped in the following
three subtype
1. Sutures are immobile
joints in the cranium. The
plate-like bones of the
skull are slightly mobile at
birth because of the
connective tissue between
them, termed fontanelles.
8. Conti..
• This initial flexibility allows the infant’s head to get through
the birth canal at delivery and permits the enlargement of the
brain after birth.
• As the skull enlarges, the fontanelles reduce to a narrow layer
of fibrous connective tissue that suture the bony plates
together. Eventually, cranial sutures ossify- the two adjacent
plates fuse to form one bone (termed synostosis).
9. 2. Gomphoses
. Gomphoses are the immobile
joints between the teeth and
their sockets in the mandible
and maxillae. The periodontal
ligament is the fibrous tissue
that connects the tooth to the
socket.
10. Syndesmoses
3. Syndesmoses are slightly movable
joints (amphiarthroses). In
syndesmosis joints, the two bones
are held together by an interosseous
membrane. Eg Middle Tibiofibular
Joint, a fibrous joint formed by the
interosseus membrane connecting
the shafts of the tibia and the fibula
11. Cartilaginous joints
• Cartilaginous joints are a type of joint
where the bones are entirely joined by
cartilage, either hyaline cartilage or
fibrocartilage.
• These joints generally allow more
movement than fibrous joints but less
movement than synovial joints.
12. 1.Primary cartilaginous joints
• Primary cartilaginous joints: These cartilaginous joints are
composed entirely of hyaline cartilage and are known as
synchondroses. Most exist between ossification centres of
developing bones and are absent in the mature skeleton, but a
few persist in adults. eg First Sternocostal Joint, between
first rib and manubrium (all other sternocostal joints are plane
synovial joints); Growth plates.
13. 2. secondary cartilaginous joint
• The secondary cartilaginous joint,
also known as symphysis, may
involve either hyaline or
fibrocartilage. These joints are
slightly mobile (amphiarthroses). eg
The pubic symphysis: Intervertebral
discs
14. Synovial joint
• The primary purpose of the synovial joint is to prevent friction
between the articulating bones of the joint cavity.
• While all synovial joints are diarthroses, the extent of
movement varies among different subtypes and is often limited
by the ligaments that connect the bones.
• Nearly all joints of the limbs and most joints of the body fall
into this class
15. Synovial joints are the most common
type of joint in the body
• These joints are
termed diarthroses,
meaning they are
freely mobile.
16. Conti..
• A key structural characteristic for a synovial joint that is not
seen at fibrous or cartilaginous joints is the presence of a joint
cavity.
• The joint cavity contains synovial fluid, secreted by the
synovial membrane (synovium), which lines the articular
capsule.
• This fluid-filled space is the site at which the articulating
surfaces of the bones contact each other.
17. Conti..
• Hyaline cartilage forms the articular cartilage, covering the
entire articulating surface of each bone.
• The articular cartilage and the synovial membrane are
continuous. A few synovial joints of the body have a
fibrocartilage structure located between the articulating bones.
• This is called an articular disc, which is generally small and
oval-shaped, or a meniscus, which is larger and C-shaped.
18. • Synovial joints are often further classified by the type of
movements they permit.
• There are six such classifications: hinge (elbow), saddle
(carpometacarpal joint), planar (acromioclavicular joint), pivot
(atlantoaxial joint), condyloid (metacarpophalangeal joint),
and ball and socket (hip joint).
20. Features of all Synovial Joints
• Articular capsule with synovial membrane
• Synovial cavity containing synovial fluid
• Hyaline articular cartilage: acts like a Teflon coating over the
bone surface, allowing the articulating bones to move
smoothly against each other without damaging the underlying
bone tissue.
21. Additional features within some
Synovial Joints
• Fibrocartilage structure located between the articulating bones:
Articular disc, which is generally small and oval-shaped, or a
Meniscus, which is larger and C-shaped. These structures can
serve several functions, depending on the specific joint. Can
serve to smooth the movements between the articulating bones
eg at the temporomandibular joint.
• Intrinsic ligament: fused to or incorporated into the wall of the
articular capsule
22. • Intracapsular ligament: located inside of the articular capsule.
• Intra-capsular tendons eg. popliteus tendon within the knee
joint
• Intra-articular tendons eg. long head of biceps tendon within
the shoulder joint
23. • Knee joint. In a Synovial joint, the ends of bones are encased in smooth
cartilage. Together, they are protected by a joint capsule lined with a
synovial membrane that produces synovial fluid. The capsule and fluid
protect the cartilage, muscles, and connective tissues.
24. The six types of synovial joints are:
1. Plane Joints: Multiaxial joint, the
articular surfaces are essentially flat,
and they allow only short nonaxial
gliding movements. Examples are the
gliding joints introduced earlier—the
intercarpal and intertarsal joints, and
the joints between vertebral articular
processes. Gliding does not involve
rotation around any axis, and gliding
joints are the only examples of nonaxial
plane joints
25. Hinge Joints: Uniaxial Joint, the
cylindrical end of one bone
conforms to a trough-shaped surface
on another.
Uniaxial hinge joints
permit flexion and
extension only, typified
by bending and
straightening the elbow
and interphalangeal
joints.
2
26. 3. Pivot Joints: Uniaxial Joint, the
rounded end of one bone conforms
to a “sleeve” ring composed of
bone of another. The only
movement allowed is uniaxial
rotation of one bone around its
own long axis. An example is the
joint between the atlas and dens of
the axis, which allows you to
move your head from side to side
to indicate “no.” Another is the
proximal radioulnar joint, where
the head of the radius rotates
within a ringlike ligament secured
to the ulna.
28. The examples of saddle
joints in the body are the
carpometacarpal joints of
the thumbs.
5.
Movements allowed by
these joints are clearly
demonstrated by
twiddling your thumbs.
29. These joints are multiaxial and the most
freely moving synovial joints.
6..
30. Nerve supply of synovial joint
• Sensory and autonomic fibers innervate synovial joints:
• The autonomic nerves are vasomotor in function,
controlling the dilation or constriction of blood vessels.
• The sensory nerves of the articular capsule
and ligaments (articular nerves)
provide proprioceptive feedback from Ruffini endings
and Pacinian corpuscles. Proprioception of the joint
permits reflex control of posture, locomotion, and
movement. Free nerve endings convey pain sensation that
is diffuse and poorly localized. The articular cartilage has
no nerve supply.
31. Blood Supply
• Synovial joints receive vascular
supply through a rich anastomosis
of arteries extending from either
side of the joint ie the
periarticular plexus. Some vessels
penetrate the fibrous capsule to
form a rich plexus deeper in the
synovial membrane.
32. Clinical Anatomy
• Arthritis – inflammation that causes stiffness and pain in the
joints eg rheumatoid arthritis or gout, or degeneration
(osteoarthritis)
• Bursitis – inflammation of the bursae (fluid-filled sacs that
cushion and pad bones)
• Tendonitis – inflammation, irritation and swelling of a tendon
that is attached to the joint.
• Injury – including strain or sprain of a ligament or
nearby tendon or muscle, or bone fracture