The endothelium is a cell layer that lines the body’s blood vessels and lymphatic vessels. These cells are necessary to maintain healthy organs, tissues, and overall body function.

The cells of the endothelium release various substances that promote growth, inflammation, movement, and fluid absorption of the blood vessels.

It consists of a single layer of cells that forms the inner lining of blood and lymphatic vessels and allows interaction between the blood and body tissues. This helps support several vital body functions, such as blood flow and fluid balance. For this reason, when the endothelium is not functioning as expected, it can increase the risk of certain health issues.

Read on to find out more about the endothelium. This article discusses its location, anatomy, function, methods for keeping it healthy, and more.

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Most blood and lymphatic vessels have three layers of wall lining:

  • Adventitia: This outer layer allows the vessels to hold their shape and structure.
  • Tunica media: This middle layer is made up of muscular and elastic tissues that allow the vessel to contract and dilate.
  • Tunica intima: The innermost lining is the tunica intima. It contains the endothelium.

Endothelial cells are generally thin and elongated. However, their cell shape and structure can change depending on their place in the body. According to research, the cells can adapt when the body is under stress.

The part of an endothelial cell in direct contact with the blood is covered by glycocalyx. This is a cell lining that controls which substances can pass through the endothelium, helping control the contents of the blood.

The endothelium has many different functions and is crucial for keeping the body healthy. The functions of the endothelium can vary depending on the part of the body it is in.

Controlling vascular tone

Blood and lymphatic vessels can get wider and narrower in response to changes in the body, such as temperature or certain chemicals in the blood. Vascular tone describes how wide or narrow the vessels are.

The endothelium controls vascular tone by releasing certain chemicals that cause the vessels to either contract or dilate. These changes regulate a person’s blood pressure.

Controlling movement through vessels

To maintain a balance of fluid in the body, blood vessels can manage the amount of fluid that can pass through the vessel lining. The endothelium controls part of this process.

When the endothelium is healthy, it prevents too much fluid from moving from the vessels into other body parts.

Preventing blood clots

The endothelium produces chemicals called nitric oxide and prostacyclin. These chemicals prevent blood clots by keeping the blood fluid.

Blood clots can happen when the blood in a certain area of the body stays still for too long. Certain conditions are associated with blood clots.

Learn more about blood clots.

The epithelium is a tissue that covers all surfaces in the body. Epithelial cells vary in function and adapt to the part of the body they are in.

Endothelial cells are a specialized type of epithelium. While the endothelium only covers internal areas of the body, the epithelium also lines external tissues, such as the skin.

Epithelial cells generally function as a protective barrier against things outside the body, such as viruses, that could threaten a person’s health. Endothelial cells are specialized to manage moving cells between vessels and other parts of the body.

Endothelial dysfunction happens when the endothelium cannot function in the typical way. This condition is a type of coronary heart disease that causes blood vessels to narrow instead of opening and allowing healthy blood flow.

The main symptom of endothelial dysfunction is chest pain, often worsened by physical activity.

Certain factors can increase a person’s risk of endothelial dysfunction. These include:

Endothelial dysfunction can increase the risk of developing several other health conditions, including:

Certain lifestyle factors can help keep the endothelium healthy. Managing conditions that may increase the risk of endothelial dysfunction, such as diabetes and high blood pressure, can help promote endothelial health.

It is best for someone concerned about their vascular health to contact their doctor for advice.

The endothelium makes up the inner lining of blood and lymphatic vessels. Endothelial cells carry out several functions that are vital to maintaining a healthy body.

When the endothelium is not functioning healthily, this is called endothelial dysfunction. It can lead to several other health issues, including stroke and heart failure.

Individuals can help maintain their endothelial health by managing conditions that can cause damage to the endothelium. A person may also wish to consult their doctor for advice on reducing the risk of endothelial dysfunction.