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
b. Syndesmoses:
Articulating bones are held together (without touching each other) by fibrous or interossoeus ligaments.
Allow slight movement: twisting of forearm (pronation and supination)
e.g. Inferior tibiofibular joint, interosseous ligament between shafts of radius and ulna
c. Gomphoses:
A peg fits into a socket.
Mostly immovable and some may have very slight movement of teeth in their sockets.
e. g. roots of teeth in alveolar processes of mandible and maxillae
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
b. Syndesmoses:
Articulating bones are held together (without touching each other) by fibrous or interossoeus ligaments.
Allow slight movement: twisting of forearm (pronation and supination)
e.g. Inferior tibiofibular joint, interosseous ligament between shafts of radius and ulna
c. Gomphoses:
A peg fits into a socket.
Mostly immovable and some may have very slight movement of teeth in their sockets.
e. g. roots of teeth in alveolar processes of mandible and maxillae
