JOINTS AND RELATED
TERMS
Dr. Farhat Aamir
At the end of this session, the
student should be able to:
• Identify sub division of skeletal system.
• Identify structural, functional and regional classification of
joints.
• Define and describe the structure of cartilaginous, fibrous
and synovial joints.
• Identify common terms related to like tendon, ligament,
bursae, aponeurosis and raphe.
• Identify clinical applications.
Sub divisions of skeletal system
• The axial skeleton
Eighty bones
• The appendicular
skeleton.
Total one twenty six
bones
Axial skeleton
Skull
 Cranium 8
 Face 14
 Auditory ossicles 6
 Hyoid 1
 Vertebrae (including sacrum and coccyx) 26
 Sternum 1
 Ribs 24
Appendicular skeleton
• Shoulder girdles
Clavicle 2
Scapula 2
• Upper extremities
Humerus 2
Radius 2
Ulna 2
Carpals 16
Metacarpals 10
Phalanges 28
• Pelvic girdle
• Hip bone 2
• Lower extremities
Femur 2
Patella 2
Fibula 2
Tibia 2
Tarsals 14
Metatarsals 10
Phalanges 28
Joints
• Articulation between
two or more bones is
defined as joints.
• Structurally three
subtypes:
Fibrous
Cartilaginous joint
Synovial joint
Joints
• On the basis of
movement
Synarthrosis
(Immovable)
 Fibrous joint
Amphiarthrosis
(slightly movable)
 Cartilaginous joint
Diarthrosis (Freely
movable joint)
 Synovial joint
Fibrous joint
• Connected by collagen
fibers
• Three types
• Sutures: skull
• Syndesmosis
• Gomphosis: present
between teeth and
mandible/maxilla
Cartilaginous joints
• Two types
• Primary and secondary
cartilaginous joints
• Primary also known as
Synchondrosis.
• Between epiphysis and
diaphysis
• First rib and manubrium
• Joined by plate of
hyaline cartilage
Cartilaginous joints
• Secondary cartilaginous
joint is termed as
symphysis.
• Bones are connected by
a plate of fibrocartilage
and the articular surfaces
of the bones are covered
by a thin layer of hyaline
cartilage.
• Examples: joints
between the vertebral
bodies and the
symphysis pubis.
Synovial Joints
• The articular surfaces
covered by a thin layer of
hyaline cartilage separated
by a joint cavity
• Permits a great degree of
freedom of movement.
• The cavity of the joint is
lined by synovial
membrane
• Outside synovial
membrane is lined by thick
membrane known as
capsule
Synovial Joints
• Articular surfaces are
lubricated with fluid
known as synovial fluid
• Ligaments present within
the capsule are
intracapsular.
• For example: cruciate
ligament in knee joint.
• Ligament present
outside the capsule are
extracapsular.
Synovial Joints
• Divided on the base
of shape
• Plane , hinge, pivot,
bicondylar, condylar
(ellipsoid), saddle, and
ball and socket
• Divided on the basis of
movement as uniaxial,
biaxial and
multiaxial.
Synovial Joints
• Plane joints: articular
surfaces are flat
• Permits sliding
movement
• For example:
intercarpal joints,
intertarsal joints
• Hinge joints: like of
the door
• Examples are elbow
and ankle joint
Synovial Joints
• Pivot joints: central
bony pivot is present
• Surrounded by bony
ring
• Rotatory movement
present
• Atlantoaxial joint and
superior radioulnar
joint.
Synovial Joints
• Ellipsoid joint/condyloid
•
•
•
•
•
•
joint: elliptical convex
articular surfaces fit with
elliptical concave surfaces
Flexion, extension,
abduction and adduction
Small circumduction
Wrist joint
Ball and socket joint:
Permits maximum
movement
Shoulder joint and hip joint
Synovial Joints
• Bicondylar joints:
•
•
•
•
•
•
movement in one axis with
limited rotation
Two condyles articulates
with concave surface
Flexion, extension,
abduction and adduction
with slight rotation
Knee joint
Saddle joint: reciprocally
concavoconvex
Resembles saddle
Carpometacarpal joint of
thumb
Ligaments and bursae
• Ligament: Cord or
band of connective
tissue joining two
bones
• Mainly composed of
collagen fibers
• Bursa: closed fibrous
sac lined with smooth
membrane
• Commonly present
close to the joints
Synovial sheath, aponeurosis and raphe
• Synovial sheath: tubular
•
•
•
•
•
bursa surrounding tendons.
Present where tendons
passes through
retinaculum or osseofibrous tunnels.
Reduce friction between
tendons and surrounding
structures.
Aponeurosis: modification
of tendon.
Thin strong sheet of fibers
Raphe: interdigitation of
tendinous ends of fibers of
flat muscles.
Clinical correlations
• Arthritis: Inflammatory
condition of the joints
• Damage to the
articular surface of
joints
• Cartilage becomes
fragile
• Formation of nodules
known as osteophytes
Clinical correlations
• Arthroscopy: Technique
of visualizing joints by
using small telescope
• Joints are approached
through small incision in
skin.
• Ligaments are prone to
stretch injuries
• Termed as sprain
• Pain, swelling and loss
of movement
Clinical correlations
• Trauma and infection
can lead to
inflammation of
synovial sheath and
bursa
• Bursitis is the term
used for inflammation
of bursa
Summary
• Sub types of skeleton
• Definition of joints
• Types
• Examples
• Subtypes of synovial joints
• Definition of ligament, bursa, aponeurosis
• Clinical correlations
References
•  Gray’s anatomy for students, 2nd edition, chapter
1, body systems, page 20-25.