Structure Of Synovial Joint

 

Dear friends, today i am going to share with you an article on structure of synovial joint. This article includes synovial fluid, synovial cavity, articular capsule and many other interesting topics. So Enjoy this article.

Synovial Joint Structure:

Most common and most complex type of joint present in the human body.

Synovial Fluid:

Its functions are:

• Nutrient distribution

• Lubrication

• Shock absorption.

Location:

Synovial cavity of a joint

Synovial Cavity:

Space enclosed by articular capsule

Articular Capsule:

Continuous  with the periosteum of articulating bones a fibrous capsule is present , which is known as articular capsule.

Layers:

It has two layers:

i. Outer Fibrous Layer

ii. Inner Synovial Layer (Synovium)

1. Outer Fibrous Layer:

Made With:

Fibrous Tissue called capsular ligament.

Function Of Capsular Ligament:

i. Holds together articulating bones 

ii. Supports the synovium.

2. Inner Synovial Layer (synovium):

It is a dense vascularised layer of connective tissue. 

Function Of Inner Synovial:

Absorbs and secretes synovial fluid

Responsible for the mediation of nutrient exchange between joint and blood.

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Articular Cartilage

It is a thin layer of hyaline cartilage which covers the bones of synovial joint and protect the ephiphysis (end) of the bone.

Function:

Smooth surface of articular cartilage has two functions:

i. Reduce Friction

ii. Serves as shock absorber

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Accessory Ligaments

Accessory ligaments serves as parts of joint capsule.

Bundles of regular connective tissue adapted to resist strain, make accessory ligaments

Function:

Reduces the chances of damage of joint during any extreme movement.

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Bursae

Small sac fulfilled with synovial fluid and  lined by synovial membrane is known as bursae.

Location:

At important parts of friction in a joint, enables the joints with free movement.

Bursitis:

Inflammation occurs in bursae due to over use of joints followed by irritation and infection is known as bursitis.

Examples of  friction points:

Common location for bursitis is where tendons run over the joint.

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Innervation

Articular nerves provide rich nerve supply to joints . 

Hilton’s Law:

Statement:

This law states that those nerves which supply joints also supply the muscles of that joints and the skin covering  their distal attachment.

Nerves of the joints transmitting impulses which play a key role in proprioception.

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Vasculature

Articular artries arising from the vessels around the joints supply blood to joints.

Location Of Articular Artries:

Within Joint Capsule mostly in the synovial membrane.

Feature Of Articular Supply:

Frequent anastomoses :- Ensurig  blood supply to and across the joint regardless of its position. 

Arteries are located above and below a joint.

The articular veins go along with the articular arteries and are also present in the synovial membrane.