Mucopolysaccharide hyaluronic acid is present in –
**Core Concept**
Mucopolysaccharides, also known as glycosaminoglycans (GAGs), are long chains of sugar molecules that play a crucial role in the structure and function of connective tissue in the body. Hyaluronic acid is a specific type of mucopolysaccharide that is highly hydrated and provides lubrication and cushioning in various tissues.
**Why the Correct Answer is Right**
Hyaluronic acid is present in high concentrations in the vitreous humor of the eye, where it helps to maintain the gel-like consistency of the vitreous body. It also plays a role in the synovial fluid, which lubricates joints and tendons, allowing for smooth movement. Additionally, hyaluronic acid is found in the umbilical cord, where it helps to maintain the integrity of the cord and facilitate the passage of nutrients and waste products between the fetus and the placenta.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because hyaluronic acid is not primarily associated with muscle tissue. While it may be present in small amounts, it is not a key component of muscle structure or function.
**Option B:** This option is incorrect because hyaluronic acid is not a primary component of blood vessels. While it may be present in the extracellular matrix of blood vessels, it is not a key factor in their structure or function.
**Option C:** This option is incorrect because hyaluronic acid is not primarily associated with the skin. While it may be present in small amounts, it is not a key component of skin structure or function.
**Clinical Pearl / High-Yield Fact**
Hyaluronic acid is highly hygroscopic, meaning it has a strong affinity for water. This property allows it to attract and retain large amounts of water, making it an important component of the extracellular matrix in various tissues.
**Correct Answer: D. Umbilical cord**