endothelium
Quick Summary
The endothelium is a specialized type of tissue that forms the inner lining of blood vessels and internal body cavities. It is composed of a single layer of thin, flattened cells derived from mesodermal origin.12
This layer plays a crucial role in regulating the passage of substances between the blood and surrounding tissues, including nutrients and waste products. The endothelium is also involved in the process of angiogenesis, which is the growth of new blood vessels. This process is vital for tissue repair but can also contribute to abnormal conditions like tumor growth. Diseases such as atherosclerosis can affect the endothelium, leading to fat deposition within the vessel lining.1
Ask Britannica AI about this topic
Britannica doesn't have a full article on this topic, so we've curated a list of our relevant coverage.
- arteriosclerosis
…of a blood vessel (the endothelium of the intimal layer) becomes injured. Some factors that cause mechanical damage to the endothelium are high cholesterol and triglycerides (a type of lipid, or fat), high blood pressure, and tobacco smoke. People who have an abnormally large amount of cholesterol or other lipids…
Read More…of a blood vessel (the endothelium of the intimal layer) becomes injured. Some factors that cause mechanical damage to the endothelium are high cholesterol and triglycerides (a type of lipid, or fat), high blood pressure, and tobacco smoke. People who have an abnormally large amount of cholesterol or other lipids…
Read More 
atherosclerosis…in the innermost layer of endothelium of the large and medium-sized arteries. Atherosclerosis is the most common arterial abnormality characterized as arteriosclerosis, which is defined by the loss of arterial elasticity due to vessel thickening and stiffening.
Read More…in the innermost layer of endothelium of the large and medium-sized arteries. Atherosclerosis is the most common arterial abnormality characterized as arteriosclerosis, which is defined by the loss of arterial elasticity due to vessel thickening and stiffening.
Read More
blood vessel…of cells known as the endothelium. The endothelium is separated from the tough external layers of the vessel by the basal lamina, an extracellular matrix produced by surrounding epithelial cells. The endothelium plays a critical role in controlling the passage of substances, including nutrients and waste products, to and from…
Read More…of cells known as the endothelium. The endothelium is separated from the tough external layers of the vessel by the basal lamina, an extracellular matrix produced by surrounding epithelial cells. The endothelium plays a critical role in controlling the passage of substances, including nutrients and waste products, to and from…
Read More
human cardiovascular systemThe blood vessels…an inner surface of smooth endothelium covered by a surface of elastic tissues. The tunica media, or middle coat, is thicker in arteries, particularly in the large arteries, and consists of smooth muscle cells intermingled with elastic fibres. The muscle cells and elastic fibres circle the vessel. In larger vessels…
Read More…an inner surface of smooth endothelium covered by a surface of elastic tissues. The tunica media, or middle coat, is thicker in arteries, particularly in the large arteries, and consists of smooth muscle cells intermingled with elastic fibres. The muscle cells and elastic fibres circle the vessel. In larger vessels…
Read More
human respiratory systemThe gas-exchange region…capillaries are lined by flat endothelial cells with thin cytoplasmic extensions. The interalveolar septum is covered on both sides by the alveolar epithelial cells. A thin, squamous cell type, the type I pneumocyte, covers between 92 and 95 percent of the gas-exchange surface; a second, more cuboidal cell type, the…
Read More…capillaries are lined by flat endothelial cells with thin cytoplasmic extensions. The interalveolar septum is covered on both sides by the alveolar epithelial cells. A thin, squamous cell type, the type I pneumocyte, covers between 92 and 95 percent of the gas-exchange surface; a second, more cuboidal cell type, the…
Read More
sepsisPathophysiology…function of endothelial tissue (the endothelium forms the inner surface of blood vessels), in the coagulation (blood clotting) process, and in blood flow. These changes appear to be initiated by the cellular release of pro-inflammatory substances in response to the presence of infectious microorganisms. The substances, which include short-lived regulatory…
Read More…function of endothelial tissue (the endothelium forms the inner surface of blood vessels), in the coagulation (blood clotting) process, and in blood flow. These changes appear to be initiated by the cellular release of pro-inflammatory substances in response to the presence of infectious microorganisms. The substances, which include short-lived regulatory…
Read More