What are synarthrosis joints and examples

Synarthrosis joints are a type of joint that occurs between two bones that are joined together and cannot move freely. These joints are also known as fixed joints or immovable joints. In a synarthrosis joint, the bones that are connected are tightly connected and there are no gaps or spaces that allow movement.

What’s that

Synarthrosis is a type of joint in which the bones in this joint cannot move relative to each other or are very restricted. Synarthrosis joints usually consist of fibrous synarthrosis, cartilaginous synarthrosis, and synostosis (osseous joints).


There are several types of synarthrotic joints commonly found in the human body. Here are some examples:

  • Sutural joints: These joints are found in the skull and the bones of the skull are joined together. For example, the sutures in a baby’s skull.
  • Synchondrosis joints: These joints are formed by hyaline cartilage that connects two bones. For example, the physeal epiphyseal joint in long bones is located between the epiphysis and diaphysis.
  • Syndesmosis joint: This joint consists of connective tissue that connects two bones. For example, the joint between the shin bone (fibula) and shin bone (tibia) in the ankle.
  • Synostosis joint: This joint occurs when two bones that were originally separate grow together and fuse into one. For example, in the pelvis, there are synostotic joints between the bones that form the pelvis.

In synarthrosis joints, the main function is to provide strength and stability to the body. Although these joints do not allow free movement, they play an important role in maintaining the structural integrity and strength of the body.


In the human body, joints are crucial for enabling movement and providing stability. However, not all joints are designed for mobility. Synarthrosis joints, also known as immovable joints, play a unique role in skeletal structure by providing stability and support without allowing significant movement. In this article, we will explore synarthrosis joints, their types, and their importance in maintaining the structural integrity of the human body.

Understanding Synarthrosis Joints:

Synarthrosis joints are specialized joints characterized by their immobility or limited movement. These joints are designed to provide stability and support to the skeletal system rather than facilitating motion. They are held together by dense fibrous connective tissue or cartilage, which helps to prevent movement between the bones.

Types of Synarthrosis Joints:

  • 1. Suture Joints: Suture joints are found between the bones of the skull and are held together by thin layers of fibrous connective tissue. The fibrous tissue allows a small amount of movement during growth and development but becomes immobile in adulthood, providing maximum stability and protection to the brain.
  • 2. Gomphosis Joints: Gomphosis joints are unique to the teeth. They are formed when the root of a tooth is firmly anchored within the bony socket of the jaw. The fibrous periodontal ligament holds the tooth in place, preventing significant movement.
  • 3. Synchondrosis Joints: Synchondrosis joints are characterized by a plate of hyaline cartilage that connects the bones. These joints are found in areas such as the growth plates in long bones during childhood, where they aid in bone development. Once growth is complete, these joints ossify and become immovable.
  • 4. Synostosis Joints: Synostosis joints occur when two separate bones fuse together, forming a single bone. An example of a synostosis joint is the fusion of the skull bones during development or the fusion of the radius and ulna in the forearm.

Importance of Synarthrosis Joints:

While synarthrosis joints do not allow significant movement, they play a vital role in maintaining the structural integrity of the body. These immovable joints provide stability and support to the skeletal system, protecting vital organs and facilitating proper body alignment. They also contribute to the overall strength and resilience of the skeletal structure.

In addition, synarthrosis joints are essential during growth and development. For example, synchondrosis joints in the growth plates of long bones allow for bone lengthening until adulthood. Once growth is complete, these joints fuse, contributing to the overall stability and strength of the skeletal system.


Synarthrosis joints, or immovable joints, are an integral part of the human skeletal system. While they do not provide significant mobility, these joints play a crucial role in maintaining stability, supporting vital organs, and ensuring proper alignment of the body. Understanding the types and functions of synarthrosis joints helps to appreciate their importance in the overall structure and function of the human body.

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