Development Of Embryo During Pregnancy! Trivia Questions

Based on the given information, the woman is experiencing severe abdominal pain on the right side with signs of abdominal bleeding. She is sexually active without contraception and has missed her last menstrual period. These symptoms and history suggest the possibility of an ectopic tubal pregnancy. In an ectopic pregnancy, the fertilized egg implants outside the uterus, typically in the fallopian tube. This can cause severe abdominal pain and bleeding. Therefore, ectopic tubal pregnancy must be included as an option in the diagnosis.

The inner cell mass of the blastocyst will give rise to the embryo. This is because the inner cell mass contains the cells that will differentiate and develop into the various tissues and organs of the embryo, including the ectoderm, endoderm, and mesoderm. The outer cell mass, known as the trophoblast, will develop into the placenta and other supporting structures.

The diagnosis in this case is placenta previa. Placenta previa is a condition where the placenta is located in the lower part of the uterus, covering or partially covering the cervix. This can cause episodes of bright red vaginal bleeding, especially in the later stages of pregnancy. The fact that the bleeding subsided each time suggests that it was not due to a more serious condition such as a hydatidiform mole or vasa previa. Premature rupture of the amniotic membrane and toxemia of pregnancy are unrelated to the symptoms described.

The mother is most likely to have contracted the acute viral infection during weeks 1-5 after fertilization because this is the time when the baby's organs are forming, including the heart. Exposure to the rubella virus during this period can lead to the development of ventriculoseptal cardiac defect in the baby.

During gastrulation, the primitive streak is formed, which is the first indication of this process. The primitive streak is a structure that forms on the surface of the developing embryo and marks the beginning of the formation of the three germ layers: ectoderm, mesoderm, and endoderm. It is responsible for the migration and organization of cells during embryonic development, leading to the formation of various organs and tissues. Therefore, the formation of the primitive streak is a crucial event in gastrulation.

The zona pellucida is not necessary for blastocyst implantation. The zona pellucida is a glycoprotein-rich layer surrounding the oocyte and early embryo, providing protection and mediating sperm binding during fertilization. However, once the blastocyst reaches the uterus, it hatches out of the zona pellucida to allow for implantation into the endometrium. Therefore, the zona pellucida is not directly involved in the process of blastocyst implantation.

Epiblast cells are the correct answer because during embryonic development, the epiblast cells give rise to all three germ layers - ectoderm, mesoderm, and endoderm. The mesoderm is one of these germ layers and is formed from the epiblast cells. Therefore, the epiblast cells play a crucial role in the formation of the mesoderm during early embryonic development.

Ectopic pregnancies most often occur in the ampullae region of the uterine tube. This is because the fertilized egg usually implants and develops in the uterus, but in the case of an ectopic pregnancy, the egg implants outside of the uterus, most commonly in the fallopian tube. The ampullae region of the uterine tube is the widest and most common site for implantation, making it the most likely location for an ectopic pregnancy to occur.

The amniotic cavity appears on the eighth day as a slit-like space between the trophoblast and the embryoblast. The embryoblast is the inner cell mass of the blastocyst, which gives rise to the embryo. As the embryo develops, the amniotic cavity forms within the embryoblast and becomes surrounded by the amnion, a protective membrane. This cavity is essential for the development and protection of the growing embryo, providing a fluid-filled environment for it to develop and grow.

The lens of the eye is formed from the ectoderm. During embryonic development, a portion of the ectoderm invaginates to form a structure called the lens placode. This placode then further develops into the lens vesicle, which eventually gives rise to the lens of the eye. The other options listed, such as the lateral plate mesoderm, neural crest cells, endoderm, and intermediate mesoderm, do not contribute to the formation of the lens.

The correct answer is False. Intraembryonic mesoderm is located between the endoderm and ectoderm at both the buccopharyngeal membrane and the cloacal membrane.

Neural crest cells are a group of cells that migrate from the neural tube during embryonic development and contribute to the formation of various structures, including craniofacial tissues and the outflow tract of the heart. Therefore, it is not surprising to see craniofacial abnormalities and a cardiac defect involving the outflow tract of the heart in a newborn, as both areas are influenced by the contribution of neural crest cells.

The correct answer is that the uteroplacental circulation is established during the second week of development. This means that during the second week of pregnancy, the placenta begins to form and the circulation between the mother and the developing embryo is established. This circulation is essential for the exchange of nutrients and waste products between the mother and the developing fetus.

The epiblast is a layer of cells in the early embryo that gives rise to the three germ layers: ectoderm, mesoderm, and endoderm. The primitive streak is a structure that forms during gastrulation, which is the process of cell movement and differentiation that establishes the three germ layers. Therefore, the statement "It forms the primitive streak" is correct because the epiblast is responsible for the formation of the primitive streak.

If an embryo failed to form the mesoderm germ layer, the aorta would not develop. The mesoderm germ layer gives rise to various structures including the cardiovascular system, which includes the aorta. Therefore, if the mesoderm germ layer fails to form, the development of the aorta would be affected.

A sacrococcygeal teratoma is a tumor that arises from remnants of the primitive streak. The primitive streak is a structure that forms during early embryonic development and gives rise to the three germ layers - ectoderm, mesoderm, and endoderm. In some cases, cells from the primitive streak can persist and give rise to tumors, such as sacrococcygeal teratomas. These tumors typically occur at the base of the spine and can contain a variety of tissues, including skin, hair, teeth, and even more complex structures like bone and muscle.

The extraembryonic mesoderm is located between the exocoelomic membrane and the cytotrophoblast.

Melanocytes are derived from neural crest cells. During development, neural crest cells migrate from the neural tube to various parts of the body, including the skin. Once in the skin, neural crest cells differentiate into melanocytes, which are responsible for producing the pigment melanin. This pigment gives color to the skin, hair, and eyes. Therefore, the correct answer is neural crest cells.

The dermis of the skin is derived from the mesoderm, not the ectoderm. The ectoderm gives rise to the epidermis, which is the outermost layer of the skin, as well as structures such as hair, nails, and glands. The enamel of teeth, forebrain, and mammary gland are also derived from the ectoderm. However, the dermis, which is the layer of skin beneath the epidermis, is derived from the mesoderm.

The excretory units of the urinary system are derived from the intermediate mesoderm. This layer of mesoderm gives rise to the urogenital system, which includes the kidneys, ureters, bladder, and urethra. These structures play a crucial role in the excretion of waste products and regulation of fluid balance in the body.

The splitting of the lateral plate mesoderm forms the intraembryonic cavity. This cavity is located within the developing embryo and is surrounded by the mesoderm. It plays a crucial role in the development of various organs and structures, such as the cardiovascular system and the gut. The formation of the intraembryonic cavity is an important step in the early embryonic development and is essential for the proper organization and differentiation of the growing embryo.