Practical Exam Embryonic Development Flashcards
Maternal capillary day 7
On day 7 of embryonic development, the maternal capillaries play a crucial role in providing the necessary blood flow to the developing embryo. The blastocyst has implanted in the lining of the uterus and established a functional connection to the maternal blood vessels, allowing for the exchange of oxygen and nutrients between the mother and the embryo.
The maternal blood vessels are located in the lining of the uterus and provide the oxygen, nutrients, and hormones that the developing embryo needs to grow and develop. The maternal capillaries also help to remove waste products and carbon dioxide from the embryo.
The process by which the developing embryo establishes a connection with the maternal blood vessels is called placentation. By day 7 of embryonic development, the placentation process is well underway, and the developing embryo is well-supplied with the necessary oxygen and nutrients to continue its growth and development.
Epiblast day 7
On day 7 of embryonic development, the epiblast is playing a crucial role in the formation of the embryonic disk, which is a bilaminar structure that consists of the epiblast and the hypoblast. The embryonic disk will eventually give rise to the embryonic cells that will form all the organs and structures of the body.
The epiblast forms the outer layer of the embryonic disk and it will give rise to the embryonic cells that will form all the organs and structures of the body. The epiblast will differentiate into different cell types to form the three germ layers: endoderm, mesoderm and ectoderm. The endoderm will form the lining of the gut and other organs, the mesoderm will form the muscles, bones, blood vessels and other organs, and the ectoderm will form the skin, hair, nails, and nervous system.
Additionally, the epiblast will form the amniotic cavity which will surround the embryo and will be filled with amniotic fluid. The amniotic fluid provides a protective environment for the developing embryo and helps maintain a constant temperature and cushioning for the fetus.
Hypoblast day 7
On day 7 of embryonic development, the hypoblast is playing a crucial role in the formation of the embryonic disk, which is a bilaminar structure that consists of the epiblast and the hypoblast. The embryonic disk will eventually give rise to the embryonic cells that will form all the organs and structures of the body.
The hypoblast forms the inner layer of the embryonic disk, and it gives rise to the endoderm, which will form the lining of the gut and other organs. The endoderm will differentiate into different cell types to form the lining of the digestive and respiratory tracts, as well as other organs such as the liver, pancreas and thyroid.
Additionally, the hypoblast will give rise to the yolk sac, which is an important source of nutrients for the developing embryo. The yolk sac will produce primitive blood cells and contribute to the formation of the umbilical cord and gut.
Synctiotrophoblast day 7
The syncytiotrophoblast is a layer of cells that forms part of the placenta and plays a crucial role in embryonic development on day 7. The syncytiotrophoblast is derived from the trophoblast cells, which are cells that surround the blastocyst and will give rise to the placenta.
The syncytiotrophoblast is a multinucleated cell layer that forms the outer layer of the developing placenta, it is in contact with the maternal blood vessels and is responsible for the transfer of oxygen, nutrients, and hormones from the mother to the developing embryo. It also helps to remove waste products and carbon dioxide from the embryo.
The syncytiotrophoblast produces human chorionic gonadotropin (hCG), a hormone that is important for maintaining the pregnancy. hCG is also used as a marker for pregnancy diagnosis.
Amniotic cavity day 8
On day 8 of embryonic development, the amniotic cavity begins to form as a space between the embryonic disk and the inner layer of the amniotic membrane. This cavity will eventually fill with amniotic fluid, which will cushion and protect the developing embryo. The amniotic fluid also helps to regulate the temperature of the embryo, and allows for movement and development of the limb buds and other structures. Additionally, the amniotic fluid allows the embryo to float and move inside the amniotic sac, which is important for proper growth and development.
Hypoblast day 8
On day 8 of embryonic development, the hypoblast is a layer of cells that forms beneath the epiblast, it is a part of the inner cell mass of the blastocyst. The hypoblast cells migrate and differentiate to form the endoderm, which will eventually give rise to the lining of the gut and respiratory system, as well as other organs such as the liver, pancreas and thyroid. The endoderm will form the yolk sac and the gut, which will play a role in the production of blood cells and other important functions like the production of the first gut cells.
Maternal capillary day 8
On day 8 of embryonic development, the maternal capillaries are blood vessels in the mother’s uterus that provide oxygen and nutrients to the developing embryo. The embryo at this stage is still in the blastocyst stage and has not yet implanted in the uterus wall, so it relies on the nutrients and oxygen supplied by the mother’s blood vessels. The maternal capillaries also help to remove waste products and carbon dioxide from the developing embryo, through the process of diffusion. Once the embryo implants in the uterus wall, the umbilical cord will form and the placenta will develop, which will take over the function of providing oxygen and nutrients to the developing embryo and removing waste products.
Syncytiotrophoblast day 8
The syncytiotrophoblast is a layer of cells that forms on the outer surface of the developing embryo on day 8 of embryonic development. It plays a critical role in the early stages of pregnancy by facilitating the transfer of nutrients and oxygen from the mother to the developing embryo, as well as by secreting hormones that help to maintain the pregnancy. Additionally, the syncytiotrophoblast plays a key role in the formation of the placenta, which is the organ that connects the developing embryo to the mother’s uterus and allows for the exchange of nutrients and waste products between the two.
Trophoblastic lacuna day 9
On day 9 of embryonic development, the trophoblastic lacuna is the spaces formed between the syncytiotrophoblast and cytotrophoblast cells of the developing placenta. These spaces are important for the early stages of embryonic development as they allow for the exchange of nutrients, oxygen and waste products between the embryo and the mother.
The syncytiotrophoblast cells that line the lacuna are responsible for the formation of the chorionic villi, small finger-like projections that extend into the uterine wall. These villi allow for the exchange of gases, nutrients and waste products between the maternal blood and the embryonic blood, they also help to anchor the embryo to the uterus.
The cytotrophoblast cells that line the lacuna are eventually responsible for forming the chorionic membrane, which surrounds the developing embryo and the amniotic cavity. This membrane helps to protect the embryo and maintain a constant environment for the developing embryo by producing amniotic fluid.
In summary, the trophoblastic lacuna plays a important role in the early embryonic development by enabling the exchange of nutrients, oxygen and waste products between the mother and the embryo, allowing for the formation of the chorionic villi and the chorionic membrane, which are essential for the survival and proper development of the embryo.
Amniotic cavity day 9
On day 9 of embryonic development, the amniotic cavity is forming as a fluid-filled space within the developing embryo. The amniotic cavity is lined by the amnion, a membrane that surrounds the developing embryo and helps to protect it from mechanical shocks and changes in temperature. It also helps to maintain a constant environment for the developing embryo by producing amniotic fluid, which cushions and supports the embryo as it grows. Additionally, the amniotic fluid serves as a medium for the exchange of gases and waste products between the embryo and the mother.
Syncytiotrophoblast day 9
On day 9 of embryonic development, the syncytiotrophoblast is a layer of cells that forms the outermost layer of the developing placenta. The syncytiotrophoblast plays a crucial role in embryonic development by facilitating the exchange of nutrients, oxygen and waste products between the mother and the embryo.
The syncytiotrophoblast cells form the chorionic villi, small finger-like projections that extend into the uterus. These villi allow for the exchange of gases, nutrients and waste products between the maternal blood and the embryonic blood, they also help to anchor the embryo to the uterus.
The syncytiotrophoblast cells also produce human chorionic gonadotropin (hCG) hormone, which is important for maintaining the pregnancy by preventing the shedding of the uterine lining, this hormone also helps to support the development of the corpus luteum, which produces the progesterone that is essential for maintaining the pregnancy.
In summary, the syncytiotrophoblast plays a critical role in embryonic development by facilitating the exchange of nutrients, oxygen and waste products between the mother and the embryo through the formation of the chorionic villi, and it also produces hCG hormone which helps to maintain the pregnancy by preventing the shedding of the uterine lining and supporting the development of the corpus luteum.
Heusers membrane day 9
On day 9 of embryonic development, Heuser’s membrane is not a structure that is formed during embryonic development. Heuser’s membrane, also known as the exocoelomic membrane is a structure that forms in the early embryonic stages but it is formed before day 9.
It forms as a thin membrane that separates the exocoelomic cavity from the embryonic disc, the exocoelomic cavity is the space between the inner cell mass (ICM) and the trophoblast cells.
The Heuser’s membrane eventually ruptures and disappears as the embryonic development progresses.
It is important to note that Heuser’s membrane is not a structure that plays any significant role in the embryonic development and its formation is not observable on day 9.
Coagulation plug day 9
On day 9 of embryonic development, the coagulation plug or fibrin plug is not a structure that forms during embryonic development. The coagulation plug or fibrin plug is a structure that forms at the implantation site after the blastocyst attaches to the endometrium, the uterine lining. It is formed as a result of the process of implantation which occurs after day 9 during the embryonic development.
The fibrin plug is a temporary barrier that helps to seal the opening of the uterus, preventing any decidual cells, bacteria or other foreign materials from entering the uterus and potentially harming the developing embryo. It also helps to prevent bleeding at the site of implantation. The coagulation plug is formed through the process of coagulation, where blood clotting factors are activated and fibrin, a protein involved in blood clotting, is deposited at the site of implantation.
It is important to note that, the coagulation plug or fibrin plug is not formed on day 9 of embryonic development, it forms later during the process of implantation, and its main function is to protect the developing embryo by sealing the uterus after the blastocyst attaches to the endometrium.
Umbilical cord cross section
A cross section of the umbilical cord would reveal its internal structure, which typically includes three vessels: two umbilical arteries and one umbilical vein. The umbilical artery carries deoxygenated blood and waste products away from the fetus to the placenta, while the umbilical vein carries oxygenated blood and nutrients from the placenta to the fetus.
The umbilical cord is surrounded by a protective covering known as the Wharton’s jelly, a gelatinous substance that provides mechanical support and cushioning for the umbilical cord and it also helps to prevent the vessels from kinking. The Wharton’s jelly is derived from mesenchymal cells and it is rich in extracellular matrix components such as proteoglycans and glycosaminoglycans.
The umbilical cord also contains a small amount of amniotic fluid, which helps to protect the umbilical cord from compression and damage. Additionally, the umbilical cord contains a few nucleated cells which are cells that have a visible nucleus.
In summary, a cross section of the umbilical cord would reveal the internal structure of the umbilical cord, which contains three vessels (two umbilical artery, one umbilical vein) surrounded by the Wharton’s jelly and a small amount of amniotic fluid, and also contains a few nucleated cells.
Cytotrophoblast day 7
On day 7 of embryonic development, the cytotrophoblast is a layer of cells that surrounds the inner cell mass and will give rise to the placenta. It is responsible for invading the endometrial lining of the uterus, and forming the primary and secondary umbilical vesicles which will eventually form the placenta and umbilical cord. The cytotrophoblast also secretes human chorionic gonadotropin (hCG) which helps to maintain the pregnancy by preventing the shedding of the endometrial lining. Additionally, it plays a role in the formation of the maternal blood supply to the developing embryo.
