This document discusses the different types of joints in the human body. It begins by defining a joint and classifying joints by function and structure. The three main types by function are synarthrosis (immovable), amphiarthrosis (slightly movable), and diarthrosis (freely movable). The three main types by structure are fibrous, cartilaginous, and synovial joints. It then provides details on the different types of synovial joints and examples of various joints in the body like the shoulder, elbow, hip, knee, ankle joints. It concludes with a brief description of bursae and fontanels.

1. JOINTS
BY
SONI KUMARI SHAH

2. Joints
A joint is the site at which any two or more bones articulate or come
together.
Joints allow flexibility and movement of the skeleton and allow
attachment between bones.
Joints can be classified by function (extent of movement) or by structure
(what they’re made of).
The body has three major types of joints classified by function and three
major types classified by structure.

3. Functional Classification
By function, a joint may be classified as:
1. Synarthrosis (immovable)
2. Amphiarthrosis (slightly movable)
3. Diarthrosis (freely movable).
Structural Classification
By structure, a joint may be classified as:
1. Fibrous Joint
2. Cartilaginous Joint
3. Synovial Joint.

4. Fibrous joints
With fibrous joints, the articular surfaces of the two bones are bound closely
by fibrous connective tissue, and little movement is possible.
Fibrous joints include
Sutures (such as in skull)
syndesmosis (such as the radioulnar joints)
gomphosis (such as the dental alveolar joint).

5. Cartilaginous Joints
These joints are formed by a pad of tough fibrocartilage that acts as a shock
absorber. Cartilaginous joints allow slight movement.
They occur as:
Primary cartilaginous joint or synchondroses, which are typically temporary
joints in which the intervening hyaline cartilage converts to bone by
adulthood— for example, the epiphyseal plates of long bones
Secondary cartilaginous joint or symphyses, which are joints with an
intervening pad of fibrocartilage— for example, the symphysis pubis.

6. Cartilaginous Joints

7. Synovial Joints
Synovial joints are characterized by the presence of a
space or capsule between the articulating bones.
The ends of the bones are held close together by a sleeve
of fibrous tissue, and lubricated with a small amount of
fluid.
Synovial joints are the most moveable of the body.
Freely movable or diarthrosis, synovial joints include most
joints of the arms and legs.

8. Structure Of Synovial Joint
Articular or hyaline cartilage
The parts of the bones in contact with each other
are coated with hyaline cartilage. This provides a
smooth articular surface, reduces friction and is
strong enough to absorb compression forces and
bear the weight of the body.
Capsule or capsular ligament
The joint is surrounded and enclosed by a sleeve
of fibrous tissue which holds the bones together.
It is sufficiently loose to allow freedom of
movement but strong enough to protect it from
injury.

9. Structure Of Synovial Joint
Synovial membrane
This epithelial layer lines the capsule and
covers all non weight- bearing surfaces
inside the joint. It secretes synovial fluid.
Other intracapsular structures
Some joints have structures within the
capsule to pad and stabilize the joint, e.g.
fat pads and menisci in the knee joint.

10. Structure Of Synovial Joint
Extracapsular structures
Ligaments that blend with the capsule
stabilize the joint.
Muscles or their tendons also provide
stability and stretch across the joints they
move. When the muscle contracts it shortens,
pulling one bone towards the other.
joint cavity: a potential space that separates
the articulating surfaces of the two bones

11. Synovial Fluid
This is a thick sticky fluid, of egg-white consistency, which fills the synovial
cavity.
Functions Of Synovial Fluid:
nourishes the structures within the joint cavity
contains phagocytes, which remove microbes and cellular debris
acts as a lubricant
maintains joint stability
prevents the ends of the bones from being separated, as does a little
water between two glass surfaces.

12. Movements At Synovial Joints
Movement at any given joint depends on various factors, such as the
tightness of the ligaments holding the joint together, how well the bones
fit and the presence or absence of intracapsular structures.
Generally, the more stable the joint, the less mobile it is.

16. Types Of Synovial Joints
Gliding Joint/Plane Joint
Hinge Joint
Pivot Joint
Condylar Joint/Ellipsoid Joint
Saddle Joint and
Ball and socket Joint

17. Gliding Joints
Gliding joints have flat or slightly curved
articular surfaces and allow gliding
movements.
However, because they’re bound by
ligaments, they may not allow movement in
all directions.
Examples: intertarsal and intercarpal joints
of the feet and hands.

18. Hinge Joints
With hinge joints, a convex portion of one bone fits into a concave
portion of another.
The articulating ends of the bones fit together like a hinge on a door,
and movement is therefore restricted to flexion and extension.
Examples: elbow joint and knee joint.

19. Pivot Joints
A rounded portion of one bone in a pivot joint fits into a groove in another
bone. One bone fits into a hoop-shaped ligament that holds it close to
another bone and allows it to rotate in the ring thus formed.
These joints allow a bone or a limb to rotate. Pivot joints allow only uniaxial
rotation of the first bone around the second.
Example: proximal radioulnar joint

20. Condyloid Joints
A condyle is a smooth, rounded projection on a
bone and in a condyloid joint it sits within a cup-
shaped depression on the other bone.
Condylar joints allow flexion, extension,
abduction, adduction, and circumduction.
Examples: radiocarpal and metacarpophalangeal
joints of the hand.

21. Saddle Joints
The articulating bones fit together like a man sitting on a saddle.
Saddle joints resemble condylar joints but allow greater freedom of
movement.
Example: carpometacarpal joints of the thumb.

22. Ball And Socket Joints
The head of one bone is ball-shaped and articulates with a cup-shaped
socket of another.
The joint allows for a wide range of movement, including flexion,
extension, adduction, abduction, rotation and circumduction.
Examples: shoulder joint and hip joint.

23. Bursae
Bursae are small synovial fluid sacs that are
located at friction points around joints between
tendons, ligaments, and bones.
Bursae act as cushions to decrease stress on
adjacent structures.
Examples of bursae include the subacromial bursa
(located in the shoulder) and the prepatellar
bursa (located in the knee).

24. Which statement about cartilage is true?
A. It receives a generous blood supply.
B. It protects body structures.
C. It’s completely flexible.
D. It cushions and absorbs shock.
The type of joint that permits free movement is classified as:
A. synarthrosis.
B. cartilaginous.
C. diarthrosis.
D. fibrous.
The carpometacarpal joints of the thumb are classified as:
A. pivot joints.
B. saddle joints.
C. hinge joints.
D. gliding joints.

25. Temporomandibular Joint
Type: condylar joint
Articular surface:
Upper part: articular tubercle and mandibular fossa of temporal bone
Lower part: head of mandible
Movements:
Depression
Elevation
Protrusion
Retraction

26. Glenohumeral Joint/Shoulder Joint
Type: ball and socket joint
Articulating surfaces:
Head of humerus
Glenoid cavity of scapula
Muscles:
Supraspinatus
Infraspinatus
Teres minor
Subscapularis

27. Glenohumeral Joint/Shoulder Joint
Supporting ligaments:
Glenohumeral ligament
Coracohumeral ligaments
Movements:
Flexion
Extension
Abduction
Adduction
Lateral rotation
Medial rotation
Circumduction

28. Elbow Joint
Type: hinge joint
Articular surface:
capitulum and trochlea of humerus
trochlear notch of ulna and head of radius
Movements:
flexion
extension

29. Radioulnar joint
Proximal Radioulnar Joint
Type: pivot joint
Articular surface: Head of radius
Radial notch of ulna
Distal Radioulnar Joint
Type: pivot joint
Articular surface: Head of ulna
Ulnar notch of radius
Movements:
Supination
Pronation

30. Wrist Joint
Type: ellipsoid joint
Articular surface:
Upper: inferior surface of lower end of radius articular disc of inferior
radioulnar joint
Lower: scaphoid lunate triquetral bones
Movements:
Flexion
Extension
Abduction
Adduction

31. Joints of hands
Intercarpal joints
Carpometacrpal joint
Metacarpophalangeal joint
Interphalangeal joint

32. Hip Joint
Type: ball and socket joint
Articular surface:
Head of femur
Acetabulum of hip bone
Supporting ligaments:
Iliofemoral ligaments
Pubofemoral ligament
Transverse ligament
Ischiofemoral ligament

33. Hip Joint
Muscles:
Gluteus maximus
Gluteus medius
Gluteus minimus
Iliopsoas
Movements:
Flexion
Extension
Abduction
Adduction
Lateral rotation
Medial rotation

34. Knee Joint
Type: condyloid joint
Articular surface:
Condyle of femur
Condyle of tibia
Patella
Supporting ligaments:
Patellar ligament
Collateral ligament: medial and lateral
Cruciate ligament: anterior and posterior

35. Knee Joint
Muscles:
Popliteus
Quadriceps femoris
Hamstring muscles:
Movements:
Flexion
Extension

36. Tibiofibular Joints
Superior Tibiofibular Joint
Type: plane synovial joint
Articular surface: Head of fibula
Lateral condyle of tibia
Inferior Tibiofibular Joint
Type: plane synovial joint
Articular surface: Roughened opposed surface of lower ends of tibia and fibula

37. Ankle Joint
Type: hinge joint
Articular surface:
Lower end of tibia with its medial malleolus
Lateral malleolus of fibula
Talus
Movements:
Dorsiflexion
Plantarflexion

38. Joints Of Foot
Intertarsal joints
Tarsometatarsal joints
Metatarsophalangeal joint
Interphalangeal joint

39. Fontanels
A fontanelle is an anatomical feature of the infant human skull
comprising any of the soft membranous gaps (sutures) between the
cranial bones that make up the calvaria of a fetus or an infant.