Chapter 10 Conception and Fetal Development

In evaluating information taught about conception and fetal development, the client verbalizes understanding about transportation time of the zygote through the fallopian tube and into the cavity of the uterus with which statement? 1. "It will take at least 3 days for the egg to reach the uterus." 2. "It will take 8 days for the egg to reach the uterus." 3. "It will only take 12 hours for the egg to go through the fallopian tube." 4. "It will take 18 hours for the fertilized egg to implant in the uterus."

Answer: 1 Explanation: 1. "It will take at least 3 days for the egg to reach the uterus" is the correct statement.

At her first prenatal visit, a woman is discussing fetal development with the nurse. The client asks, "When will my baby actually have a heartbeat?" The nurse should say the heartbeat of an embryo is distinguishable by what time? 1. "The fourth week" 2. "The sixth week" 3. "The eighth week" 4. "The twelfth week"

Answer: 1 Explanation: 1. By the end of the fourth week, embryonic blood is circulating between the embryo and the chorionic villi.

The nurse is working with a client who has experienced a fetal death in utero at 20 weeks. The client asks what her baby will look like when it is delivered. Which statement by the nurse is best? 1. "Your baby will be covered in fine hair called lanugo." 2. "Your child will have arm and leg buds, not fully formed limbs." 3. "A white, cheesy substance called vernix caseosa will be on the skin." 4. "The genitals of the baby will be ambiguous."

Answer: 1 Explanation: 1. Downy fine hair called lanugo covers the body of a 20-week fetus.

The client at 20 weeks' gestation thinks she might have been exposed to a toxin at work that could affect fetal development. The client asks the nurse what organs might be affected at this point in pregnancy. What is the nurse's best response? 1. "The brain is developing now, and could be affected." 2. "Because you are in the second trimester, there is no danger." 3. "The internal organs like the heart and lungs could be impacted." 4. "It's best to not worry about possible problems with your baby."

Answer: 1 Explanation: 1. Maximum brain growth and myelination are occurring at this point in fetal development. Page Ref: 190

The nurse teaching the expectant parents about the placenta also talks about the circulation and how the fetus gets its oxygen. She will include in this teaching which important fact? 1. The placenta functions as the lungs for the fetus. 2. The fetus obtains its oxygen from the amniotic fluid. 3. The fetus receives its oxygen by osmosis from the mother's bloodstream. 4. Fetal circulation delivers the highest amount of oxygen to the abdomen and lower body of the fetus.

Answer: 1 Explanation: 1. Most of the blood supply bypasses the fetal lungs because they do not carry out respiratory gas exchange. The placenta assumes the function of the fetal lungs by supplying oxygen and allowing the fetus to excrete carbon dioxide into the maternal bloodstream.

The nurse is caring for a client pregnant with twins. Which statement indicates that the client needs additional information? 1. "Because both of my twins are boys, I know that they are identical." 2. "If my twins came from one fertilized egg that split, they are identical." 3. "If I have one boy and one girl, I will know they came from two eggs." 4. "It is rare for both twins to be within the same amniotic sac."

Answer: 1 Explanation: 1. Not all same-sex twins are identical or monozygotic, because fraternal, or dizygotic, twins can be the same gender or different genders.

A client tells you that her mother was a twin, two of her sisters have twins, and several cousins either are twins or gave birth to twins. The client, too, is expecting twins. Because there is a genetic predisposition to twins in her family, there is a good chance that the client will have what type of twins? 1. Dizygotic twins 2. Monozygotic twins 3. Identical twins 4. Nonzygotic twins

Answer: 1 Explanation: 1. Studies indicate that dizygotic twins tend to occur in certain families, perhaps because of genetic factors that result in elevated serum gonadotropin levels leading to double ovulation.

The pregnant client who is at 14 weeks' gestation asks the nurse why the doctor used to call her baby an embryo, and now calls it a fetus. What is the best answer to this question? 1. "A fetus is the term used from the ninth week of gestation and onward." 2. "We call a baby a fetus when it is larger than an embryo." 3. "An embryo is a baby from conception until the eighth week." 4. "The official term for a baby in utero is really zygote."

Answer: 1 Explanation: 1. The fetal stage begins in the ninth week.

The nurse educator is presenting a program to college students about factors that can cause congenital malformations. What should the nurse tell them? 1. The growing embryo is considered most vulnerable to hazardous agents during the first months of pregnancy. 2. Spontaneous abortion always occurs if the fetus is affected by a teratogen. 3. Potential teratogens can cause malformations of the heart, limbs, eyes, and other organ systems only in the second trimester. 4. Teratogen agents are primarily drugs.

Answer: 1 Explanation: 1. This is true. Because organs are formed primarily during embryonic development, the growing embryo is considered most vulnerable to hazardous agents during the first months of pregnancy.

After explaining how meiotic division occurs within the ovum, the nurse knows that the pregnant client understands when she makes what statement? 1. "The second meiotic division is arrested until and unless the oocyte is fertilized." 2. "Meiosis in the oocyte begins at puberty." 3. "The first meiotic division continues when the female infant is born." 4. "Fertilization does not take place in the secondary oocyte."

Answer: 1 Explanation: 1. This is true. The secondary oocyte moves into the metaphase stage of cell division, where its meiotic division is arrested until and unless the oocyte is fertilized.

The nurse is teaching about reproduction, and explains that which of the following are the purposes of meiosis? Select all that apply. 1. Produce gametes 2. Reduce the number of chromosomes 3. Introduce genetic variability 4. Produce cells for growth and development 5. Divide somatic cells into new cells with identical characteristics

Answer: 1, 2, 3 Explanation: 1. Meiosis is a special type of cell division by which diploid cells give rise to gametes (sperm and ova). 2. The cells contain half the genetic material of the parent cell-only 23 chromosomes-the haploid number of chromosomes. 3. During meiosis new combinations of cells are provided by the newly formed chromosomes; these combinations account for the wide variation of traits.

The nurse is teaching the significance of good nutrition on fetal development to a group of young women. What factors will the nurse discuss? 1. Vitamins and folic acid are important before conception. 2. Maternal nutrition may predispose to the development of adult coronary heart disease, hypertension, and diabetes. 3. Glucose, amino acids, and fatty acids are of high importance. 4. Nutrition is important only during the first trimester. 5. Maternal nutrition can affect brain and neural tube development.

Answer: 1, 2, 3, 5 Explanation: 1. Vitamins and folic acid supplements taken before conception can reduce the incidence of neural tube defects. 2. This is true. Maternal nutrition may predispose to the development of adult coronary heart disease, hypertension, and diabetes. 3. Amino acids, glucose, and fatty acids are considered to be the primary dietary factors in brain growth. 5. Adequacy of the maternal environment is also important during the periods of rapid embryonic and fetal development. Maternal nutrition can affect brain and neural tube development.

The nurse educator is teaching student nurses what a fetus will look like at various weeks of development. Which descriptions would be typical of a fetus at 20 weeks' gestation? 1. The fetus has a body weight of 435-465 g. 2. Nipples appear over the mammary glands. 3. The kidneys begin to produce urine. 4. Nails are present on fingers and toes. 5. Lanugo covers the entire body.

Answer: 1, 2, 4, 5 Explanation: 1. A fetus at 20 weeks' gestation has a body weight of 435-465 g. 2. A fetus at 20 weeks' gestation has nipples appear over the mammary glands. 4. A fetus at 20 weeks' gestation nails are present on fingers and toes. 5. A fetus at 20 weeks' gestation has lanugo that covers the entire body.

The nurse is holding a class for newly pregnant couples, and discussing good and bad influences on their developing babies. Prenatal influences on the intrauterine environment include which of the following? 1. The use of saunas or hot tubs 2. The use of drugs 3. The quality of the sperm or ovum 4. Maternal nutrition 5. Vitamins and folic acid

Answer: 1, 2, 4, 5 Explanation: 1. The use of saunas or hot tubs is associated with maternal hyperthermia. Studies of the effects of maternal hyperthermia during the first trimester have raised concern about possible spontaneous abortion, central nervous system (CNS) defects, and failure of neural tube closure. 2. The use of drugs can have teratogenic effects. 4. Maternal nutrition affects brain and neural tube development. 5. Vitamins and folic acid supplements taken before conception can reduce the incidence of neural tube defects.

The OB-GYN nurse teaches a first-time pregnant client that functions of the amniotic fluid include which of the following? 1. Allowing fetal freedom of movement 2. Releasing heat to control fetal temperature 3. Acting as an extension of fetal extracellular space 4. Providing a water source for the fetus to swallow 5. Acting as a wedge during labor

Answer: 1, 3, 5 Explanation: 1. Amniotic fluid permits fetal freedom of movement. 3. A primary function of amniotic fluid is to act as an extension of fetal extracellular space. 5. A primary function of amniotic fluid is to act as a wedge during labor.

Student nurses in their obstetrical rotation are learning about fertilization and implantation. The process of implantation is characterized by which statements? Select all that apply. 1. The trophoblast attaches itself to the surface of the endometrium. 2. The most frequent site of attachment is the lower part of the anterior uterine wall. 3. Between days 7 and 10 after fertilization, the zona pellucida disappears, and the blastocyst implants itself by burrowing into the uterine lining. 4. The lining of the uterus thins below the implanted blastocyst. 5. The cells of the trophoblast grow down into the uterine lining, forming the chorionic villi.

Answer: 1, 3, 5 Explanation: 1. During implantation, the trophoblast attaches itself to the surface of the endometrium for further nourishment. 3. Between days 7 and 10 after fertilization, the zona pellucida disappears, and the blastocyst implants itself by burrowing into the uterine lining and penetrating down toward the maternal capillaries until it is completely covered. 5. The cells of the trophoblast grow down into the thickened lining, forming the chorionic villi.

The nurse is teaching a group of adolescents that sperm must undergo the process of capacitation in order to fertilize the ova. The characteristics of sperm that have undergone capacitation include which of the following? Select all that apply. 1. Ability to undergo an acrosomal reaction 2. Ability to block polyspermy 3. Ability to bind to the zona pellucida 4. Ability to release norepinephrine 5. Acquisition of hypermotility

Answer: 1, 3, 5 Explanation: 1. Sperm that undergo capacitation take on the ability to undergo the acrosomal reaction. 3. Sperm that undergo capacitation take on the ability to bind to the zona pellucida. 5. Sperm that undergo capacitation have the acquisition of hypermotility.

The nurse is presenting a class to pregnant clients. The nurse asks, "The fetal brain is developing rapidly, and the nervous system is complete enough to provide some regulation of body function on its own, at which fetal development stage?" It is clear that education has been effective when a participant makes which response? 1. "The 17th-20th week" 2. "The 25th-28th week" 3. "The 29th-32nd week" 4. "The 33rd-36th week"

Answer: 2 Explanation: 2. Between the 25th and 28th week, the brain is developing rapidly, and the nervous system is complete enough to provide some degree of regulation of body functions.

A pregnant woman tells the nurse-midwife, "I've heard that if I eat certain foods during my pregnancy, the baby will be a boy." The nurse-midwife's response should explain that this is a myth, and that the sex of the baby is determined at what time? 1. At the time of ejaculation 2. At fertilization 3. At the time of implantation 4. At the time of differentiation

Answer: 2 Explanation: 2. Fertilization is the point at which the sex of the zygote is determined.

During a class on genetics for pregnant families, the nurse is discussing the how the egg and sperm are formed before fertilization takes place. The nurse explains that these cells have only half the number of chromosomes, so when fertilization takes place, there will be the correct number. What is the process by which the egg and sperm are formed called? 1. Oogenesis 2. Gametogenesis 3. Meiosis 4. Spermatogenesis

Answer: 2 Explanation: 2. Gametogenesis is the process by which ovum and sperm are produced.

During a prenatal examination, an adolescent client asks, "How does my baby get air?" What correct information would the nurse give? 1. "The lungs of the fetus carry out respiratory gas exchange in utero similar to what an adult experiences." 2. "The placenta assumes the function of the fetal lungs by supplying oxygen and allowing the excretion of carbon dioxide into your bloodstream." 3. "The blood from the placenta is carried through the umbilical artery, which penetrates the abdominal wall of the fetus." 4. "The fetus is able to obtain sufficient oxygen due to the fact that your hemoglobin concentration is 50% greater during pregnancy."

Answer: 2 Explanation: 2. The placenta assumes the function of the fetal lungs by supplying oxygen and allowing the excretion of carbon dioxide into the maternal bloodstream.

The nurse is teaching the students in their obstetric rotation about fertilization. What processes must the sperm undergo before fertilization can occur? 1. Capacitation and ovulation 2. Capacitation and the acrosomal reaction 3. Oogenesis and the acrosomal reaction 4. Gametogenesis and capacitation

Answer: 2 Explanation: 2. The sperm must undergo two processes before fertilization can occur: capacitation and the acrosomal reaction. Page Ref: 173

The true moment of fertilization occurs when what happens? 1. Cortical reaction occurs 2. Nuclei unite 3. Spermatozoa propel themselves up the female tract 4. Sperm surrounding the ovum release their enzymes

Answer: 2 Explanation: 2. The true moment of fertilization occurs as the nuclei unite. Their individual nuclear membranes disappear, and their chromosomes pair up to produce the diploid zygote.

A woman pregnant with twins asks the nurse about differences between identical and fraternal twins. The nurse explains that since it has been determined that she is having a boy and a girl, they are fraternal, and will have with of the following? 1. One placenta, two amnions, and two chorions 2. Two placentas, two amnions, and two chorions 3. Two placentas, one amnion, and two chorions 4. Two placentas, two amnions, one chorion

Answer: 2 Explanation: 2. This is the correct answer. Fraternal twins have two placentas, two amnions, and two chorions, however, the placentas sometimes fuse and look as if they are one.

A pregnant client at 28 weeks' gestation asks the nurse what her baby is like at this stage of pregnancy. How would the nurse describe the fetus? 1. The fetus is developing subcutaneous fat. 2. The fetus is now opening and closing her eyes. 3. The baby could now breathe on her own, if she were born. 4. The fetus has fingernails and toenails. 5. The fetus is forming surfactant needed for lung function.

Answer: 2, 3, 5 Explanation: 2. At 28 weeks, the eyes begin to open and close. 3. At 28 weeks, the delivered baby can breathe. 5. At 28 weeks, the fetus has the surfactant formed needed for breathing.

Which statement by a pregnant client to the nurse would indicate that the client understood the nurse's teaching? 1. "Because of their birth relationship, fraternal twins are more similar to each other than if they had been born singly." 2. "Identical twins can be the same or different sex." 3. "Congenital abnormalities are more prevalent in identical twins." 4. "Identical twins occur more frequently than fraternal twins."

Answer: 3 Explanation: 3. Monozygotic twinning is considered a random event and occurs in approximately 3 to 4 per 1000 live births. Congenital anomalies are more prevalent and both twins may have the same malformation.

he nurse is creating a poster for pregnant mothers. Which description of fetal development should the nurse include? 1. Four primary germ layers form from the blastocyst. 2. After fertilization, the cells only become larger for several weeks. 3. Most organs are formed by 8 weeks after fertilization. 4. The embryonic stage is from fertilization until 5 months.

Answer: 3 Explanation: 3. Most organs are formed during the embryonic stage, which lasts from the 15th day after fertilization until the end of the 8th week after conception.

The nurse is creating a handout on reproduction for teen clients. Which piece of information should the nurse include in this handout? 1. The fertilized ovum is called a gamete. 2. Prior to fertilization, the sperm are zygotes. 3. Ova survive 12-24 hours in the fallopian tube if not fertilized. 4. Sperm survive in the female reproductive tract up to a week.

Answer: 3 Explanation: 3. Ova are considered fertile for about 12 to 24 hours after ovulation.

The nurse has completed a presentation on reproduction. Which statement indicates that the teaching has been successful? 1. "A male is born with all the sperm he will ever produce." 2. "Females create new ova throughout their reproductive life." 3. "Ova separate into two unequally sized cells." 4. "Each primary spermatocyte divides into four haploid cells."

Answer: 3 Explanation: 3. The first meiotic division produces two cells of unequal size with different amounts of cytoplasm but with the same number of chromosomes.

The nurse is explaining the difference between meiosis and mitosis. Which statements would be best Select all that apply. 1. Meiosis is the division of a cell into two exact copies of the original cell. 2. Mitosis is splitting one cell into two, each with half the chromosomes of the original cell. 3. Meiosis is a type of cell division by which gametes, or the sperm and ova, reproduce. 4. Mitosis occurs in only a few cells of the body. 5. Meiotic division leads to cells that halve the original genetic material.

Answer: 3, 5 Explanation: 3. Meiosis is a special type of cell division by which diploid cells give rise to gametes (sperm and ova). 5. Meiosis creates two cells that contain half the genetic material of the parent cell.

The nurse explains to a preconception class that if only a small volume of sperm is discharged into the vagina, an insufficient quantity of enzymes might be released when they encounter the ovum. In that case, pregnancy would probably not result, because of which of the following? 1. Peristalsis of the fallopian tube would decrease, making it difficult for the ovum to enter the uterus. 2. The block to polyspermy (cortical reaction) would not occur. 3. The fertilized ovum would be unable to implant in the uterus. 4. Sperm would be unable to penetrate the zona pellucida of the ovum.

Answer: 4 Explanation: 4. About a thousand acrosomes must rupture to clear enough hyaluronic acid for even a single sperm to penetrate the ovum's zona pellucida successfully. If only a small amount of sperm were released, there most likely would be an insufficient quantity of acrosomes to penetrate the zona pellucida of the ovum and allow fertilization.

The client has read that the placenta produces hormones that are vital to the function of the fetus. It is evident that that the client understands the function of the placenta when she states that which hormone is primarily responsible for the maintenance of pregnancy past the 11th week? 1. Human chorionic gonadotropin (hCG) 2. Human placental lactogen (hPL) 3. Estrogen 4. Progesterone

Answer: 4 Explanation: 4. Progesterone is a hormone essential for pregnancy. After the 11th week, the placenta produces enough progesterone and estrogen to maintain pregnancy.

The nurse working with a client describes cellular multiplication and how the zygote moves through the fallopian tube, a movement that takes place via what process? 1. A squeezing motion 2. Pushing from another ovum that has not been fertilized 3. Hormone action 4. A very weak fluid current in the fallopian tube resulting from the beating action of ciliated epithelium

Answer: 4 Explanation: 4. This is correct. There is a very weak fluid current in the fallopian tube resulting from the beating action of the ciliated epithelium that lines the tube.

The nurse is preparing a class on reproduction. What is the cell division process that results in two identical cells, each with the same number of chromosomes as the original cell called? 1. Meiosis 2. Mitosis 3. Oogenesis 4. Gametogenesis

2. MitosisExplanation: 2. Mitosis results in the production of diploid body (somatic) cells, which are exact copies of the original cell.

The nurse educator is discussing human chromosomes with her students, and knows that the teaching has been effective when a student makes which statement? 1. "All humans have 48 chromosomes and 2 sex chromosomes." 2. "Human chromosomes are shaped like a 'Y'." 3. "Humans have 46 chromosomes, 2 of which are the sex chromosomes." 4. "Only certain body cells contain the chromosomes."

3. "Humans have 46 chromosomes, 2 of which are the sex chromosomes." Explanation: 3. This is the correct answer. There are 22 pairs of similar cells and 2 sex chromosomes.