Joints

1. A need for strength makes the bones rigid, but if the
skeleton consisted of only one solid bone, movement
would be impossible. Nature has solved this problem
by dividing the skeleton into many bones and
creating joints where the bones intersect. Joints, also
known as articulations, are strong connections that
join the bones, teeth, and cartilage of the body to
one another. Each joint is specialized in its shape and
structural components to control the range of motion
between the parts that it connects....

2. A R T H R O L O G Y
Science concerned with the study of joints

3. CLASSIFICATION OF JOINTS

5. 1.FIBROUS JOINTS
• Articulating bones in joints are tightly bound by
fibrous connective tissue
• Fibrous joints range from rigid to relatively
immovable joints to those that are slightly movable
CLASSIFICATION OF FIBROUS JOINTS
1. SUTURES
2. SYNDESMOSES
3. GOMPHOSES

7. CLASSIFICATION OF FIBROUS JOINTS
1.Sutures
• Immovable joint (called a synarthrosis)
• Only found between the bones of the skull.
• There is limited movement until about 20
years of age, after which they become fixed.

8. 1.Sutures
i)SERRATE SUTURE
It is characterized by interlocking saw
like articulations.
This is the most common type of
suture, an example of which is sagittal
suture between two parietal bones

9. 1.Sutures
ii)SQUAMOUS SUTURE
The squamous suture is the
connecting joint in the skull between
the parietal bone and the lower
portion of the temporal
bone. Collagen fibers develop after
birth to bind the adjacent bones
together. The squamous suture is only
located in the joints of the skull. This
type of suture joint is one of the three
types found on the skull. It is a lap
suture, which indicates the overlap of
the skull bones. Visually, it appears
smooth and blended together, with
small scale-like edges. They are unlike
serrate sutures that have serrated
edges, or plane sutures, which do not
overlap or interlock, but instead are
just flush next to the adjacent

10. 1.Sutures
iii)PLANE SUTURE
In plane suture, the edges
of the articulating bones are
fairly smooth and don't
overlap.
e.g. medial palatine suture,
where the paired maxillary
and palatine bones
articulates to form hard
palate.

11. CLASSIFICATION OF FIBROUS JOINTS
2.Syndesmoses
• Slightly movable joins (called
an amphiarthrosis)
• Usual structure is bones held together by
together by an interosseous membrane
• Middle radio-ulnar and middle tibiofibular
joint are key examples

12. Syndesmoses

13. CLASSIFICATION OF FIBROUS JOINTS
3.Gomphmoses
• Immovable joint (called a synarthrosis)
• Where the teeth articulate with their sockets
in the maxillae (upper teeth) or
the mandible (lower teeth)
• The fibrous connection that binds the tooth
and socket is the periodontal ligament

14. Gomphmoses

15. 2.CARTILAGINOUS JOINTS
• Cartilaginous joints are connected entirely
by cartilage (fibro cartilage or hyaline).
• Cartilaginous joints allow more movement
between bones than a fibrous joint but less
than the highly mobile synovial joint.
• there is NO JOINT CAVITY.

16. i)Synchondroses
• Also known as primary cartilaginous joints, they only
involve hyaline cartilage.
• Synchondroses are cartilaginous joints that
have hyaline cartilage between the articulating bones.
Some of
• these joints are temporary, forming the epiphyseal
plates (growth plates) between the diaphyses and
epiphyses in the long bones of children . When growth
is complete, these synchondrotic joints ossify. A totally
ossified synchondrosis may also be referred to as a
synostosis.

17. i)Synchondroses

19. ii)Symphyses
• Also known as a secondary cartilaginous joint, it
can involve fibro cartilage or hyaline cartilage
• Adjoining bones of a symphysis are covered with
hyaline cartilage ,which become infiltrated with
collagenous fibers to form an intervening pad of
fibro cartilage.
• The joints are slightly movable (amphiarthroses).
• An example of a symphysis is the pubic symphysis
& intervertebral joints formed by intervertebral
disc.

20. ii)Symphyses

22. 3.SYNOVIAL JOINT
• Synovial joints are most mobile type of joints.
• They possess the following characteristic features;
• There articular surfaces are covered with hyaline cartilage. This articular
cartilage is avascular, non nervous and elastic. Lubricated with synovial
fluid, the cartilage forms slippery surfaces for free movements.
• Between the articular surfaces there is a joint cavity filled with synovial
fluid. The cavity may be partially or completely subdivided by an articular
disc known as meniscus.
• The joint is surrounded by an articular capsule which is fibrous in nature
and is lined by synovial membrane. Because of its rich nerve supply the
fibrous capsule is sensitive to stretches imposed by movements.
• The synovial membrane lines the entire joint except the articular surfaces
covered by hyaline cartilage. It is this membrane that secretes the slimy
fluid called synovial fluid which lubricates the joint and nourishes the
articular cartilage.
• Varying degrees of movements are always permitted by the synovial
joints.

23. Function of Synovial Joint
The function of synovial joints is to provide
a wide range of precise, smooth movements, at
the same
time maintaining stability, strength, and in
certain aspects,
rigidity in the body.

24. STRUCTURE OF SYNOVIAL JOINT

25. KINDS OF SYNOVIAL JOINT
Classified into six main categories on the basis of
their structure & the motion they permit .
1. GLIDING
2. HINGE
3. PIVOT
4. CONDYLOID
5. SADDLE
6. BALL AND SOCKET

26. GLIDING JOINT
• Allow only side to side & back froth
movement with some slight rotation.
• Simplest type of joint movement.
• Articulating surfaces are nearly flat,or one
may be slightly concave and other slightly
convex.
• E.g intercarpal & intertarsal joints ,the
sternoclavicular joints,joint between articular
processes of adjacent vertebrae.

27. GLIDING JOINT

28. GLIDING JOINT

29. HINGE JOINT
• Hinge joints are monoaxial –like the hinge of a
door, they permit movement in only one plan.
• In this type of articulation, the surface of bone
is always concave, and the other convex.
• Hinge joints are most common type of
synovial joints.
• E.g. the knee, the humeroulnar articulation
within the elbow, and the joint between
phalanges.

30. Hinge joint

31. PIVOT JOINT
• A pivot joint is a type of diarthrosis.
• The movement at a pivot joint is limited to
rotation about a central axis.
• In this type of articulation ,the articular surface
on one bone is conical or rounded and fits into a
depression on another bone.
• e.g. are the proximal articulations of the radius &
ulna for rotation of the forearm, as in turning a
door knob, and the articulation between atlas &
axis that allow rotational movement of the head.

32. PIVOT JOINT

33. PIVOT JOINT

34. CONDYLOID JOINT
• A condyloid articulation is structured so that an
oval , convex articular surface of one bone fits
into concave depression on another bone.
• This permits angular movement in two directions
, as in up & down and side to side motions.
• Condyloid joints are therefore said to be biaxial
joints.
• e.g. The radiocarpal joint of the wrist & the
metacarpophalangeal joints

35. CONDYLOID JOINT

37. SADDLE JOINT

38. SADDLE JOINT

39. BALL & SOCKET JOINT
• The ball and socket joint (or spheroidal joint)
is a type of synovial joint in which the ball-
shaped surface of one rounded bone fits into
the cup-like depression of another bone.
• E.g. glenohumeral joint (shoulder joint) &
coxal (hip joint)

40. BALL & SOCKET JOINT

41. TYPES OF ARTICULATIONS
SYNOVIAL JOINTS MOVEMENTS
GLIDING Sliding
HINGE Bending motion in one plane
PIVOT Rotation about a central axis
CONDYLOID Movement in two planes
SADDLE Wide range of movements
BALL & SOCKET Movement in all planes & rotation