Structure and Types of Joints in the Human body

Structure and Types of
Joints in the Human Body




 A joint, also known as articulation is the place where two
adjacent bones or cartilages meet.
 Although most joints are movable, some are not.
 Movable joints provide the mechanism that allows the body to
move through coordination of nervous, skeletal and muscular
systems.
 Joints are classified on two bases:

I. On the basis of their function (Degree of movement):

 This classification is based on the degree of movement of
bones in a joint.
 According to this system, a joint may be;
 Immovable (Synarthrosis):
 Such joints don’t allow movement because bones are
rigidly joined together.
 e.g. Manubriosternal joint, the joints between the
skull bones (Sutures)
 Slightly movable (Amphiarthrosis):
 They allow limited or slight movement.

,  e.g. Pubic symphysis of the pelvis, intervertebral
joints
 Freely movable (Diarthrosis):
 They permit a great deal of movement.
 e.g. Elbow, shoulder and ankle joints

II. On the basis of their structure:

 This classification is based on the presence or absence of a
joint cavity and the kind of supporting tissue that binds the
bones together.
 According to this system, there are three types of joints;
 Fibrous joints
 Cartilaginous joints
 Synovial joints

1. Fibrous joints:

 Lack a joint cavity
 Fibrous connective tissue unites the articulating bones tightly
 Mostly immovable and some are slightly movable
 Usually synarthroses
 They are of three types;




a. Sutures:
 Found only in the skull
 Fibrous tissue connects the articulating bones in children
 Bones are permanently fused in adults
 Some movement in fetuses and young children but immovable
in adults
 e. g. Cranial sutures