Development Flashcards
When the egg moves up the Fallopian tube and has undergone meiosis 1 and is stalled in metaphase in meiosis II
Secondary Oocyte
Before the sperm cell can enter into a secondary oocyte, it must pass through the __________ __________, a layer of follicular cells
Corona radiata
After it passes the corona radiata, it has to pass through __________ __________, a layer of glycoproteins coating the oocyte surface
Zona pellucida
When the sperm makes contact with zona pellucida, it triggers a _________ __________, which is the release of a suite of digestive enzymes that permit entry of the sperm nucleus into the egg
Acrosome reaction
Sperm contain abundant ______________, that power the long journey through the female reproductive duct
Mitochondria- but any sperm mitochondria that enter the egg are destroyed
When the sperm has the oocyte on lock, the eggs releases __________ __________, that cause surface glycoproteins to form cross-links that prevent fertilization by multiple sperm, or polyspermy
Cortical granules- this process is known as cortical reaction
What does the secondary oocyte does to complete meiosis II
Form a polar body and mature, fertilized ovum, and the haploid nuclei of the sperm and ovum fuse to form what’s now a diploid, single-called zygote
While the zygote makes its journey to the uterus, it creates a 30-some trillion-cell human being by undergoing a series of mitotic divisions known as?
Cleavage
At the 16 day stage, the embryo is known as
Morula
The morula continues to divide and develops the structure of a _____________, which has fluid filled cavity called the ____________
Blastula or blastocyst; blastocoel
The outer layer of cells surrounding the blastocoel is the ___________, which would later form the ______________.
Trophoblast, placenta
The mass of cells at one pole of the cell in the blastula is known as the ________ ________ ________, which will develop into all the cells of the fetus
Inner cell mass
If the zygote implants elsewhere than the uterine wall such as in the Fallopian tube or the cervix, this is termed an _________ pregnancy
Ectopic pregnancy- generally non-viable and can even be dangerous for the mother
Requires reciprocal cooperation between the embryo and uterine tissue, which undergo structural changes and respond to hormonal signals as the embryo implants itself in the uterine endometrium
Implantation
When the embryo implants itself into the uterine endometrium, the ________ begins to form the __________, through which the fetus will exchange oxygen, nutrients, and wastes with its mother
Trophoblast, placenta
The inner mass begins to form the ____________ and ___________, which will become the ________ ________
Yolk sac and amnion, amniotic sac
A membranous sac containing amniotic fluid in which the fetus develops
Amniotic sac
Firmly implanted in the uterine wall, the blastocyst differentiates into a __________.
Gastrula
The gastrula undergoes this process which is the formation of the 3 primary germ layers
Gastrulation
The 3 primary germ layers are
Endoderm, mesoderm, and ectoderm
This gives rise to the urinary bladder and GI and respiratory tracts
Endoderm or internal-derm
Gives rise to connective tissue, muscles, circulatory system, kidneys, adrenal glands, and gonads
Mesoderm- think movement
This gives rise to the nervous system, skin, eyes, ears, nose, hair, and teeth enamel
Ectoderm or external-derm
The early development of the nervous system is known as the ___________, by which a rod of mesodermal cells form the __________, which induces the formation of the neural plate from the ectodermal cells just above it
Neurulation, notochord
