yolk sac
noun
: a membranous sac of most vertebrates that encloses the yolk, is attached in most forms (as in humans) through the yolk stalk with the intestinal cavity of the embryo, and is supplied with blood vessels that transport nutritive yolk products to the developing embryo
Examples of yolk sac in a Sentence
Recent Examples on the Web
Created from stem cells, without eggs, sperm, or a womb, the embryo model had a yolk sac and a proto-placenta, resembling a state that real human embryos reach after approximately 14 days of development.
—
Kristen V. Brown, The Atlantic, 8 Oct. 2024
The models included cells that could develop into a yolk sac, placenta or embryo.
—Theara Coleman, The Week, 15 June 2023
There’s the amniotic and yolk sac.
—refinery29.com, 30 Nov. 2020
In mice, microglia originate in the yolk sac of an embryo and then infiltrate the brain early in development.
—Kristine Zengeler, Discover Magazine, 10 Dec. 2022
By day 8, a beating heart began to circulate blood through vessels forming around the embryo’s yolk sac.
—Megan Molteni, STAT, 2 Aug. 2022
McKenna Shea Xydias, of Senoia, Georgia, had an ovarian yolk sac tumor, according to Good Morning America, and went through four rounds of chemotherapy.
—Caitlin Keating, PEOPLE.com, 20 June 2019
But in the human embryo knockouts, placental cells and yolk sac cells also failed to form.
—Gretchen Vogel, Science | AAAS, 20 Sep. 2017
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Kristen V. Brown, The Atlantic, 8 Oct. 2024
The models included cells that could develop into a yolk sac, placenta or embryo.
—Theara Coleman, The Week, 15 June 2023
There’s the amniotic and yolk sac.
—refinery29.com, 30 Nov. 2020
In mice, microglia originate in the yolk sac of an embryo and then infiltrate the brain early in development.
—Kristine Zengeler, Discover Magazine, 10 Dec. 2022
By day 8, a beating heart began to circulate blood through vessels forming around the embryo’s yolk sac.
—Megan Molteni, STAT, 2 Aug. 2022
McKenna Shea Xydias, of Senoia, Georgia, had an ovarian yolk sac tumor, according to Good Morning America, and went through four rounds of chemotherapy.
—Caitlin Keating, PEOPLE.com, 20 June 2019
But in the human embryo knockouts, placental cells and yolk sac cells also failed to form.
—Gretchen Vogel, Science | AAAS, 20 Sep. 2017
Cite this Entry
“Yolk sac.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/yolk%20sac. Accessed 27 Feb. 2025.
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