How Many Types of Joints are in The Human Body

Introduction

The connection between bones, ossicles, or other hard body components that makes up the skeletal system of an animal into a useful whole is known as a joint, articulation, or articular surface. They are built with various levels and styles of movement in mind. Some joints, including the knee, elbow, and shoulder, are practically frictionless, self-lubricating, and capable of withstanding compression and supporting enormous loads while yet allowing for fluid and accurate movement. To protect the brain and the sensory organs, other joints, like the sutures between the skull's bones, allow very limited movement (just during birth).

The junction that connects a tooth to the jawbone is also referred to as gomphosis and is characterized as being made of fibrous tissue. Joints are divided into functional and structural categories.

Joints are primarily divided into structural and functional categories

Functional classification is based on the amount of movement between the articulating bones, whereas structural classification is based on how the bones are connected to one another. The two categories of categorization frequently overlap in practice.

Structural Categories (binding tissue)

Based on their structural characteristics, joints can be categorized as cartilaginous, fibrous, or synovial. In structural classification, joints are named and categorized based on the kind of tissue that binds the bones together.

Joints can be categorized structurally into four groups.

Joints that are connected by collagen-rich, dense regular connective tissue are referred to as fibrous joints.

Joints with cartilage between them are known as cartilaginous joints. The two are as follows:

Hyaline cartilage makes up both primary cartilaginous joints and secondary cartilaginous joints, which cover the articular surfaces of the involved bones and are connected by fibrocartilage.

Synovial joints are those where the bones are not directly attached; instead, the synovial cavity and the articular capsule, which are typically connected by accessory ligaments, are formed by of dense, irregular connective tissue. A facet joint connects two articular processes on either side of two vertebrae.

Structural joints are as follows:

Fibrous Joints

Where bones are rigid, fixed joints, also known as immovable joints, are present. In such joints, bones have been joined in a way that fixes them to that component, usually to construct a structure. The skull, which is constructed of several fused bones, is a notable example of a fixed joint.

The upper jaw, ribs, backbone, pelvis, and other structures are more examples.

Joint Cartilaginous

Symphysis or synchondrosis joints make up cartilaginous joints, which are partially mobile joints. Only in areas where cartilage serves as the link between the articulating bones do these joints develop. Children with synchondrosis have transient cartilaginous joints that endure through the end of puberty.

A prime example is a pubic symphysis. The spinal column and ribcage are two further examples of Cartilagenous joint.

Synovial Joints

Because they enable us to conduct a variety of motions, including walking, running, typing, and more, synovial joints are the most prevalent type of joint. Synovial joints are adaptable, mobile, rotational, and capable of sliding over one another. These joints can be found in our shoulder, neck, knee, wrist, and other joints.

Functional categories (movement)

Additionally, joints can be categorized functionally based on the kinds and extent of motion they permit: The fundamental anatomical planes are used to explain joint motions.

Synarthrosis - restricts or prevents movement. Joints with synarthrosis are often fibrous joints (e.g., skull sutures).

Amphiarthrosis - allows for minimal motion. The majority of the joints in amphiarthrosis are cartilaginous (e.g., intervertebral discs).

An easily mobile synovial joint is also referred to as diarthrosis. According to the sort of movement they permit, synovial joints can also be divided into six groups: plane joint, ball and socket joint, hinge joint, pivot joint, condyloid joint, and saddle joint

In addition, joints can be categorised as nonaxial (gliding, such as between the proximal ends of the ulna and radius), monoaxial (uniaxial), biaxial, and multiaxial depending on how many axes of movement they permit. Another classification system separates joints with one, two, or three degrees of freedom based on the permitted degrees of flexibility. The number and types of articular surfaces are flat, concave, and convex surfaces are further categorised. Trochlear surfaces are one type of articular surface.

Functional joints are as follows:

Saddle joint

The saddle joint is a biaxial joint that permits motion in both the flexion/extension and abduction/adduction planes. For instance, the only bone in the human body with a saddle joint is the thumb.

Pivotal Joints

Full rotation is not possible in this type of joint because one bone has tapped into the other. This joint facilitates movement both forward and backwards. A neck joint that serves as a pivot.

Ball and Socket Joints

A bone is hooked into a bone's cavity in this instance. Rotatory movement is aided by this kind of joint. Shoulders are a good illustration of a ball and socket joint.

Condyloid Joints

The joints having two axes that allow for up-down and side-to-side motions are called condyloid joints. The condyloid joints can be found in the elbow, wrist, carpals, base of the index finger, and wrist joints. This joint is sometimes referred to as an ellipsoid joint or a condylar joint.

Gliding Joints

One popular category of synovial joints is the gliding joint. Another name for it is a plane or planar joint. This joint enables free movement between two or more flat or round bones without any bone friction or crushing. The majority of the time, this joint can be located where two bones connect and slide against one another in any direction.

Hinge joints

Door hinges, which solely allow for backward and forward movement, are an analogue of hinge joints. The elbows, knees, and ankle joints are examples of hinge joints.

Conclusion

Where two bones meet is called a joint. Without them, movement would not be possible since they enable the skeleton to be flexible. Our bodies may move in numerous ways thanks to joints.