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  2. Zona pellucida - Wikipedia

    en.wikipedia.org/wiki/Zona_pellucida

    The zona pellucida is an extracellular matrix that surrounds the plasma membrane of the egg cell. It helps protect the egg, and has an essential role in fertilization by sperm. It is surrounded by the corona radiata. The corona is composed of cells that care for the egg when it is emitted from the ovary. [1]

  3. Fetal membranes - Wikipedia

    en.wikipedia.org/wiki/Fetal_membranes

    The fetal membranes separate maternal tissue from fetal tissue at a basic mechanical level. The fetal membrane is composed of a thick cellular chorion covering a thin amnion composed of dense collagen fibrils. The amnion is in contact with the amniotic fluid and ensures structural integrity of the sac due to its mechanical strength.

  4. List of human cell types derived from the germ layers

    en.wikipedia.org/wiki/List_of_human_cell_types...

    This is a list of cells in humans derived from the three embryonic germ layers – ectoderm, mesoderm, and endoderm. Cells derived from ectoderm. Surface ectoderm

  5. Cortical reaction - Wikipedia

    en.wikipedia.org/wiki/Cortical_reaction

    The cortical reaction is a process initiated during fertilization that prevents polyspermy, the fusion of multiple sperm with one egg.In contrast to the fast block of polyspermy which immediately but temporarily blocks additional sperm from fertilizing the egg, the cortical reaction gradually establishes a permanent barrier to sperm entry and functions as the main part of the slow block of ...

  6. Egg cell - Wikipedia

    en.wikipedia.org/wiki/Egg_cell

    Human egg cell. The egg cell or ovum (pl.: ova) is the female reproductive cell, or gamete, [1] in most anisogamous organisms (organisms that reproduce sexually with a larger, female gamete and a smaller, male one). The term is used when the female gamete is not capable of movement (non-motile).

  7. Human reproductive system - Wikipedia

    en.wikipedia.org/wiki/Human_reproductive_system

    The human reproductive system includes the male reproductive system, which functions to produce and deposit sperm, and the female reproductive system, which functions to produce egg cells and to protect and nourish the fetus until birth. Humans have a high level of sexual differentiation.

  8. Extraembryonic membrane - Wikipedia

    en.wikipedia.org/wiki/Extraembryonic_membrane

    the chorion which surrounds all of these and in avians successively merges with the allantois in the later stages of egg development to form a combined respiratory and excretory organ called the chorioallantois. [2] In humans and other mammals they are more usually called fetal membranes.

  9. Human fertilization - Wikipedia

    en.wikipedia.org/wiki/Human_fertilization

    Human fertilization is the union of an egg and sperm, occurring primarily in the ampulla of the fallopian tube. [1] The result of this union leads to the production of a fertilized egg called a zygote, initiating embryonic development. Scientists discovered the dynamics of human fertilization in the 19th century. [2]