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Joints are places where two bones meet.There are two ways to classify joints histologically, based on the dominant type of connective tissue, or functionally, based on the range of motion.Histologically, the three body joints are fibrous, cartilaginous, and synovial.Biologically, synarthrosis (not moveable), amphiarthrosis (totally moveable), and diarthrosis (freely moveable) are the three types of joints.

Joint that is fibrous

A fibrous joint has collagen-based fibrous tissue connecting the bones.Joints made of fibrous tissue are usually immovable (synarthroses) and do not have joint cavities.Among them are sutures, gomphoses, and syndesmoses.

Cartilage synovium

During cartilaginous joints, the bones are attached to one another by hyaline cartilage or fibrous cartilage.Primary and secondary cartilaginous joints can be classified further according to their cartilage content.

The synovial joint

These joints are considered the main functional joints of the body because they are freely mobile (diarthroses).The synovial joint cavity is characteristic of synovial joints.A fibrous connective tissue surrounds the cavity and each participating bone just beyond its articulating surface.It contains synovial fluid, which is secreted by the synovial membrane (synovium) in the joint cavity.Cartilage of the articulating surface of each bone is formed from hyaline cartilage.Arthroid cartilage and synovial membrane are in continuity.

Further classification of synovial joints is often based on the type of movements they permit.

Structure and Function

Histopathological and functional classification schemes provide a broader understanding of joints.

A suture and a gomphose are found only in the skull and teeth, respectively, within the fibrous joints.

Inflammable: Syndesmosis

As well as syndesmosis, amphiarthrosis joints, and fibrous joints, another type of joint keeps long bones connected and resists attempts to separate them.Syndesmoses are all amphiarthroses, but each of them allows a certain degree of motion.It is primarily the tibiofibular syndesmosis which provides strength and stability to the leg and ankle when we bear weight; however, the antebrachial interosseous membrane of the radioulnar syndesmosis enables the radius bone to rotate when the forearm is moved.Also, muscles attach to the interosseous membranes of the leg and forearm*3.

A synchondrosis of cartilage

A synchondrosis is a primary cartilaginous joint that consists only of hyaline cartilage.

In development, a temporary synchondrosis is an epiphyseal plate (growth plate) that allows bones to grow longer.Epiphyseal plates connect the diaphysis (shaft of the bone) with the epiphysis (end of the bone) in children.Diaphysis expands as the cartilaginous plate is replaced by bone.The end result is when all the hyaline cartilage has ossified, and the diaphysis and epiphysis fuse in synostosis.Other synchondroses join the ilium, ischium, and pubis bones of the hip; over time, these also fuse into a single hip bone.

With the passage of time, the hyaline cartilage of a permanent synchondrosis does not ossify.A permanent synchondrose connects bones without moving.As an example, the first sternocostal joint of the thoracic cage joins the first rib to the manubrium through its costal cartilage.*4> The costal cartilage covers the anterior end of the other 11 ribs as well.

In a cartilaginous structure, symphysis

In a symphysis, fibrocartilage comprises the joint.Due to the thickness and strength of the cartilage in symphyses, they are able to withstand significant forces.A joint with fibrocartilage still permits limited movement, although the fibrocartilage strongly links adjacent bones.

It is possible for a symphysis to be narrow or wide.One example is the pubic symphysis. Another is the manubriosternal joint.In females, the pubic symphysis between the left and right pubic bones plays a critical role in childbirth because of its slight mobility.This is the wider symphysis of the intervertebral disc.During high-impact activities, the thick fibrocartilage pad provides cushioning between adjacent vertebrae.

The Synnovial: Overview

It is the primary purpose of the synovial joint to prevent friction between the articulating bones of the joint cavity.Synovial joints are all diarthroses, but the amount of movement varies between the different subtypes and is often restricted by the ligaments that connect the bones.

Symbol: Hinge

Joints with hinges are those where one bone's convex end articulates with another's concave end.Uniaxial joints permit only movement in one axis.The axis of movement in the body is usually bending and straightening, or flexion and extension.These include elbows, knees, ankles, and interphalangeal joints.

Condyloid: Synovial membrane

A condyloid joint, also known as an ellipsoid joint, is formed by the shallow depression of one bone and the rounded structure of another bone or bones.As the name implies, biaxial joints can move in both directions: flexion/extension and medial/lateral (abduction/adduction).In the hand, the metacarpophalangeal joints between the distal metacarpal and proximal phalanx are commonly called knuckles.

Saddle: a synovial

In biology, a saddle joint is an articulation between two bones that are saddle-shaped, or concave in one direction and convex in another.A biaxial example of this type of joint is the first carpometacarpal joint connecting the trapezium (carpal) to the first metacarpal bone of the thumb.A thumb flexes and extends within the scope of the palm as well as abducts and adducts perpendicular to the palm."Opposite" thumbs are a result of humans' dexterity.


Generally, a planar joint, or gliding joint, refers to an articulation between bones that are flat and of similar size.This joint type is multiaxial because it can move in many directions, but surrounding ligaments restrict the range of motion.Some of these joints include intercarpal joints, intertarsal joints, and acromioclavicular joints.

The Synnovial: Pivot

A pivot joint connects one bone with another through a ligamentous ring.Uniaxial joints rotate around a single axis, despite the fact that the bone is rotated within this ring.Atlantoaxial joints are those between C1 (atlas) and C2 (axis) of vertebrae, permitting side-to-side head movement.An additional example would be the proximal radioulnar joint.Radius sits in the annular radial ligament, which holds it in place while articulating with the radial notch of the ulna, allowing pronation and supination.

Socket and Ball: Synovial

A ball and socket joint consists of the rounded head of one bone and the concavity of another.An example of this type of joint would be flexion/extension, abduction/adduction, and rotation.Combined with the hip, the shoulder is the sole ball-and-socket joint of the body.In the glenoid cavity, there is a deeper socket allowing for greater range of motion in the shoulder, while in the acetabulum, and in the supporting ligaments of the hip, a shallower socket limits the movement of the femur.