Biology Chapter: Implantation and Cell Differentiation

The primary germ layers are ectoderm, mesoderm, and endoderm. Ectoderm forms structures like skin and nervous system, mesoderm forms muscles and connective tissues, and endoderm forms internal linings of organs.

The amnion is a thin, transparent membrane that surrounds the embryo, filled with amniotic fluid. It cushions the embryo, maintains temperature, and allows for free movement.

The chorion facilitates nutrient and gas exchange with the mother, produces hormones like hCG, and acts as a protective barrier against pathogens.

<p>The allantois stores metabolic waste produced by the embryo, contributes to blood vessel development, and plays a role in gas exchange.</p> Signup and view all the answers

<p>The yolk sac provides nutrients to the embryo before the placenta forms and produces the first blood cells through hematopoiesis.</p> Signup and view all the answers

<p>The ectoderm, as the outermost germ layer, forms structures that interface with the external environment, such as the skin and nervous system.</p> Signup and view all the answers

<p>The mesoderm forms connective tissues, muscles, and various internal organ systems, integrating and supporting the body.</p> Signup and view all the answers

<p>The lining of the urinary bladder, derived from the endoderm, serves as a barrier and is essential for the storage and expulsion of urine.</p> Signup and view all the answers

<p>The amnion protects the embryo by providing a cushioning effect through amniotic fluid, which absorbs shocks and reduces the risk of injury.</p> Signup and view all the answers

<p>Amniotic fluid maintains a stable temperature around the embryo, protecting it from temperature fluctuations.</p> Signup and view all the answers

<p>Chorionic villi have finger-like projections that increase surface area for exchange, allowing nutrients and gases to diffuse between maternal and fetal blood.</p> Signup and view all the answers

<p>The placenta supplies nutrients, removes wastes, and produces hormones necessary to support pregnancy.</p> Signup and view all the answers

<p>Nutrients from the mother's blood diffuse through the placenta's villi into the fetal blood, where uterine arteries supply the necessary substances.</p> Signup and view all the answers

<p>The placenta develops from both maternal and fetal tissues during the first three months of gestation, starting from the implanted blastocyst.</p> Signup and view all the answers

<p>The buoyant environment created by the amniotic fluid allows the embryo to float and move freely, supporting musculoskeletal development.</p> Signup and view all the answers

<p>The amniotic cavity provides a sterile environment that protects the embryo from pathogens.</p> Signup and view all the answers

<p>Hormones like hCG, progesterone, and estrogen are crucial for maintaining the uterine lining, suppressing uterine contractions, and supporting embryo and placenta growth.</p> Signup and view all the answers

<p>The zygote, after fertilization, undergoes mitotic divisions from one cell to multiple cells, reaching the blastocyst stage within six days, where it consists of an inner cell mass that is pluripotent.</p> Signup and view all the answers

<p>The three primary germ layers are ectoderm, mesoderm, and endoderm, which develop into all tissues and organs of the body.</p> Signup and view all the answers

<p>The ectoderm develops into the nervous system (including the brain and spinal cord), skin structures (epidermis, hair, nails), and sensory organs.</p> Signup and view all the answers

<p>The corpus luteum produces estrogen and progesterone to maintain the uterine lining and support the early stages of pregnancy until the placenta forms.</p> Signup and view all the answers

<p>Progesterone and estrogen help maintain the uterine lining and prevent contractions, which are essential for the embryo's survival and growth.</p> Signup and view all the answers

<p>During the third week, cells in the inner cell mass change to multipotent cells, leading to the formation of the three primary germ layers.</p> Signup and view all the answers

<p>hCG is crucial for signaling the corpus luteum to continue producing hormones that maintain the pregnancy and support the early development of the embryo.</p> Signup and view all the answers

<p>Active transport is the movement of larger molecules against the concentration gradient using energy, crucial for transporting nutrients into the fetus's blood.</p> Signup and view all the answers

<p>Oxygen diffuses from the mother's blood into the fetus's blood, while carbon dioxide moves from the fetus's blood to the mother's blood.</p> Signup and view all the answers

<p>The umbilical cord contains two arteries carrying deoxygenated blood and waste products from the fetus to the placenta for processing by the mother.</p> Signup and view all the answers

<p>Separate circulation prevents maternal and fetal blood from mixing while allowing the exchange of nutrients and wastes through the placenta.</p> Signup and view all the answers

<p>The placenta produces hormones that regulate pregnancy and support fetal development by maintaining appropriate conditions.</p> Signup and view all the answers

<p>A mother experiences increased blood volume, higher urine production, larger breasts, and abdominal growth.</p> Signup and view all the answers

<p>Heavily pregnant women prefer smaller meals due to reduced stomach capacity caused by the growing uterus pressing against the stomach.</p> Signup and view all the answers

<p>Hormonal levels, such as progesterone and estrogen, rise to support fetal growth and pregnancy, affecting the mother's body and emotions.</p> Signup and view all the answers

<p>Ovulation detection helps in conception by identifying the fertile window to time intercourse. For contraception, it aids in avoiding intercourse during the fertile days.</p> Signup and view all the answers

<p>The surge in luteinizing hormone (LH) and changes in estrogen levels signal the fertile window. Temperature fluctuations also indicate hormonal changes related to ovulation.</p> Signup and view all the answers

<p>Mechanical barrier methods prevent sperm from reaching the egg, with examples including condoms and diaphragms. These methods physically block sperm during intercourse.</p> Signup and view all the answers

<p>Condoms create a physical barrier that prevents sperm from entering the vagina, thereby reducing the risk of pregnancy. They also block pathogens, lowering the transmission risk of STIs.</p> Signup and view all the answers

<p>Hormonal contraceptives prevent pregnancy by inhibiting ovulation, thickening cervical mucus, and altering the uterine lining. This makes it difficult for sperm to fertilize an egg or for a fertilized egg to implant.</p> Signup and view all the answers

<p>The combined oral contraceptive pill contains both estrogen and progesterone, while the progestogen-only pill contains only progesterone. Each has different indications and side effects.</p> Signup and view all the answers

<p>Hormonal implants release progestin into the bloodstream to prevent ovulation and thicken cervical mucus for up to several years. This makes them a highly effective long-term contraceptive method.</p> Signup and view all the answers

<p>A copper IUD releases copper to prevent sperm fertilization, while a hormonal IUD releases hormones to thicken cervical mucus and inhibit ovulation. Their mechanisms of action and hormone content differ.</p> Signup and view all the answers

<p>Abstinence (D)</p> Signup and view all the answers

<p>True (A)</p> Signup and view all the answers

<p>Tubal ligation and vasectomy</p> Signup and view all the answers

<p>Copper</p> Signup and view all the answers

<p>Chlamydia = Often asymptomatic, can lead to PID Gonorrhea = Similar symptoms to chlamydia Syphilis = Distinct stages, can cause long-term issues HIV = Affects the immune system, leads to AIDS</p> Signup and view all the answers

<p>85% (A)</p> Signup and view all the answers

<p>False (B)</p> Signup and view all the answers

<p>Infertility</p> Signup and view all the answers

<p>cervical</p> Signup and view all the answers

<p>Birth control pills (B)</p> Signup and view all the answers

<p>Condoms (A)</p> Signup and view all the answers

<p>False (B)</p> Signup and view all the answers

<p>HIV</p> Signup and view all the answers

<p>abstinence</p> Signup and view all the answers

<p>Diaphragm = Barrier Method Birth control patch = Hormonal Method Vasectomy = Permanent Method Withdrawal = Behavioral Method</p> Signup and view all the answers

<p>Unusual discharge (D)</p> Signup and view all the answers

<p>False (B)</p> Signup and view all the answers

<p>Infertility</p> Signup and view all the answers

<p>condoms</p> Signup and view all the answers

<p>Tubal ligation (B)</p> Signup and view all the answers