Yolk Sac Definition

Yolk Sac in Early Pregnancy: Meaning & Function - Cleveland Clinic

The yolk sac also produces cells that turn into important structures, such as the umbilical cord, blood cells and reproductive organs.

Embryology, Yolk Sac - StatPearls - NCBI Bookshelf

Human Embryo at 14 Days With Yolk Sac). The yolk sac reduces in size ... [3] A yolk sac is defined as small or large when it falls below the fifth ...

Yolk sac - Wikipedia

The yolk sac is a membranous sac attached to an embryo, formed by cells of the hypoblast layer of the bilaminar embryonic disc. This is alternatively called ...

What Is a Yolk Sac in Pregnancy? - WebMD

A yolk sac is a small pouch made from thin membranes. The yolk sac is one of the first things to develop during pregnancy.

Yolk Sac - an overview | ScienceDirect Topics

The yolk sac is an extraembryonic membrane that surrounds the developing embryo and is derived from embryonic endoderm and mesoderm.

Yolk sac Definition & Meaning - Merriam-Webster

The meaning of YOLK SAC is a membranous sac of most vertebrates that encloses the yolk, is attached in most forms (as in humans) through the ...

Yolk sac | biology | Britannica

Other articles where yolk sac is discussed: animal development: Adaptations in animals other than mammals: …cases a membranous bag, or yolk sac, ...

Yolk Sac - an overview | ScienceDirect Topics

Yolk sac blood islands are defined as a cluster of primitive erythroblasts surrounded by an endothelial covering and nestled between the outer visceral ...

Yolk sac | Radiology Reference Article | Radiopaedia.org

Visualization of multiple yolk sacs is the earliest sign of a polyamniotic pregnancy, e.g. twins (see case 4). The number of yolk sacs matches ...

What the Yolk Sac Does During Pregnancy - What to Expect

The yolk sac is part of the gestational sac, the protective covering that surrounds a developing baby and contains the amniotic fluid. It appears about a week ...

Yolk Sac Definition & Function - Lesson - Study.com

The primary function of the yolk sac is to provide the growing embryo with nutrition and oxygen until the placenta takes over at 12 weeks. By week 20, the yolk ...

The yolk sac as the main organ in the early stages of animal ...

In marsupials, the yolk sac, devoid of yolk, persists throughout pregnancy, and in placental mammals, it completes its development at the early ...

Origin and function of the yolk sac in primate embryogenesis - Nature

Extraembryonic mesoderm is an integral part of amnion, yolk sac, allantois and chorion (Box 1), with critical roles in vascularisation and ...

Video: Yolk Sac Definition & Function - Study.com

Learn what yolk sac is in pregnancy. Discover the function of the gestational yolk sac, the yolk sac definition, and learn what the yolk sac becomes.

Definition of yolk sac tumor - NCI Dictionary of Cancer Terms

yolk sac tumor ... A rare type of cancer that begins in germ cells (cells that form sperm or eggs). Yolk sac tumors occur most often in the ovary or testicle, but ...

YOLK SAC Definition & Meaning - Dictionary.com

Yolk sac definition: an extraembryonic membrane that encloses the yolk of eggs in birds, reptiles, and marsupials and that circulates nourishment from the ...

Yolk-sac placenta Definition & Meaning - Merriam-Webster

The meaning of YOLK-SAC PLACENTA is a structure in some sharks resembling a placenta, consisting of the vascular embryonic yolk sac wall intimately ...

Yolk sac - Definition, Meaning & Synonyms - Vocabulary.com

membranous structure enclosing the yolk of eggs in birds, reptiles, marsupials, and some fishes; circulates nutrients to the developing embryo.

YOLK SAC definition in American English - Collins Dictionary

2 senses: zoology 1. the membranous sac that is attached to the ventral surface of the embryos of birds, reptiles, and some.... Click for more definitions.

yolk sac | Definition and example sentences - Cambridge Dictionary

The exocoelomic cavity contains the yolk sac, which is connected to the primitive digestive tract and fetal circulation. From the Cambridge ...