endothelium
noun
en·do·the·li·um
ˌen-də-ˈthē-lē-əm 
-dō-
plural endothelia
ˌen-də-ˈthē-lē-ə
-dō-
1
: an epithelium of mesodermal origin composed of a single layer of thin flattened cells that lines internal body cavities and the lumens of vessels
2
: the inner layer of the seed coat of some plants
Examples of endothelium in a Sentence
Recent Examples on the Web
Supports Heart Health Grape juice is rich in compounds that may help protect the endothelium, the inner lining of your blood vessels.
—
Sarah Jividen, Verywell Health, 27 Oct. 2025
When the inner lining (endothelium) leads gracefully and arteries stay limber, your cardiovascular health hits all the right notes.
—Pranjal Malewar, New Atlas, 15 Oct. 2025
In a healthy person, the endothelium helps prevent blood clots by producing chemicals that tweak the vascular system to keep it running.
—Kff Health News, San Diego Union-Tribune, 10 June 2025
The virus that causes covid can affect the vascular endothelium — specialized cells that line blood vessels and help with blood flow, Rasmussen said.
—Kff Health News, Oc Register, 2 June 2025
In a healthy person, the endothelium helps prevent blood clots by producing chemicals that keep the vascular system running.
—Jackie Fortiér, NPR, 30 May 2025
Healthy endothelium cells also play a role in local cell growth and help prevent blood clotting.
—Sandee Lamotte, CNN Money, 28 May 2025
Aging and menopause contribute to the dysfunction of the endothelium (cells of blood vessels).
—Merve Ceylan, Health, 27 Dec. 2024
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Sarah Jividen, Verywell Health, 27 Oct. 2025
When the inner lining (endothelium) leads gracefully and arteries stay limber, your cardiovascular health hits all the right notes.
—Pranjal Malewar, New Atlas, 15 Oct. 2025
In a healthy person, the endothelium helps prevent blood clots by producing chemicals that tweak the vascular system to keep it running.
—Kff Health News, San Diego Union-Tribune, 10 June 2025
The virus that causes covid can affect the vascular endothelium — specialized cells that line blood vessels and help with blood flow, Rasmussen said.
—Kff Health News, Oc Register, 2 June 2025
In a healthy person, the endothelium helps prevent blood clots by producing chemicals that keep the vascular system running.
—Jackie Fortiér, NPR, 30 May 2025
Healthy endothelium cells also play a role in local cell growth and help prevent blood clotting.
—Sandee Lamotte, CNN Money, 28 May 2025
Aging and menopause contribute to the dysfunction of the endothelium (cells of blood vessels).
—Merve Ceylan, Health, 27 Dec. 2024
Cite this Entry
“Endothelium.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/endothelium. Accessed 31 Oct. 2025.
Copy CitationMedical Definition
endothelium
noun
en·do·the·li·um
ˌen-də-ˈthē-lē-əm
plural endothelia
-lē-ə
: an epithelium of mesoblastic origin composed of a single layer of thin flattened cells that lines internal body cavities (as the serous cavities or the interior of the heart)
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