# What type of acid is in synovial fluid?

Sep 1, 2016

The acid in synovial joints is hyaluronic acid.

#### Explanation:

Synovial Joints

The adult human body contains 206 bones and approximately 300 joints.

Most of these are ball-and-socket joints (e.g. hips) or hinge joints (e.g. knees).

(From dutchsmilingyogi.com)

Synovial Fluid

Synovial fluid is a thick, stringy fluid found in the cavities of synovial joints.

Its main function is to reduce friction by lubricating and cushioning the joints as they move

Hyaluronic Acid

Hyaluronic acid (HA) is a polymer composed of repeating disaccharide units
of β-1',3-$N$-acetyl-D-glucosamine and β-1,4'-D-glucuronic acid, with a molecular mass of up to 6 × 10^6 color(white)(l) "u".

The polymer chains are held tightly together by hydrogen bonds, mostly between the carboxylic acid and N-acetyl groups.

The chains can hold up to 6 L of water per gram of hyaluronic acid, and this makes HA a great lubricant and shock absorber for the joints.