Fetal Development

Spermatogenesis is the process by which primary spermatocytes become mature sperm. When does spermatogenesis begin? -Before birth -During puberty -When secondary sex characteristics begin to develop -Late school age

During puberty Explanation: Spermatogenesis begins at puberty in the male.

A pregnant client at 10-weeks' gestation asks the nurse if the developing fetus can get infections. The nurse explains that until about 24 weeks' gestation the cytotrophoblast layer of cells protects the fetus from certain infections. The cytotrophoblast layer will protect against which of these infections? Select all that apply. -Syphilis -Gonorrhea -Group B streptococcus -HIV -Toxoplasmosis

Syphilis Gonorrhea Group B streptococcus Explanation: The cytotrophoblast layer has a secondary function to protect the growing embryo and fetus from certain infectious organisms, specifically bacteria such as spirochete of syphilis or Neisseria gonorrhea of gonorrhea and Group B streptococcus. The cytotrophoblast layer offers little protection against viral invasion at any point during pregnancy. Therefore, the developing pregnancy is at risk for infection from viruses that cause infections such as HIV and toxoplasmosis.

A pregnant patient is concerned that the baby is going to drown in the uterus because of the fluid. What should the nurse respond about fetal respiration? -"You are breathing for the baby." -"The baby's breathing is very minor until delivery." -"The baby's lungs can accommodate all of the fluid." - "Oxygen is provided to the baby through the placenta."

Oxygen is provided to the baby through the placenta." Explanation: Fetal circulation differs from extrauterine circulation because the fetus derives oxygen and excretes carbon dioxide not from gas exchange in the lung but from exchange in the placenta. The baby's lungs are not functioning in utero so the response that the baby's breathing is very minor until delivery and the baby's lungs being able to accommodate the fluid are incorrect. The patient is not "breathing for the baby."

A couple comes to the clinic for preconception counseling and care. As part of the visit, the nurse teaches the couple about fertilization and initial development, stating that the zygote formed by the union of the ovum and sperm consists of how many chromosomes? -22 -23 -44 -46

46 Explanation: With fertilization, the ovum, containing 23 chromosomes, and the sperm, containing 23 chromosomes, join, forming a zygote with a diploid number or 46 chromosomes.

The nursing student is preparing a presentation which will illustrate the various stages of fetal development. The student will label which stage as the time when the various tissues of the growing embryo begin to assume specific functions? -pre-embryonic -embryonic -fetal -post-embryonic

embryonic Explanation: During the embryonic period, the cells multiply and tissues begin to assume specific functions, a process known as differentiation. This stage lasts from the end of the second week after fertilization until the end of the eighth week. The pre-embryonic stage begins with fertilization and lasts for 2 weeks. Cellular division and implantation occur during this stage of development. The fetal stage is from the beginning of the ninth week after fertilization and continues until birth. There is additional growth and maturation of the organs and body systems during this time. There is no post-embryonic stage.

The school nurse is presenting a lecture to adolescents to teach them how conception occurs. Which statement by the nurse would accurately describe this process? -"Human life begins with the union of two cells: the zygote and the sperm." -"At the time of conception, the ovum determines the sex of the baby." -"Conception usually occurs when the ovum is in the outer third of the fallopian tube." -"The ovum carries the Y chromosome, and the sperm carries an X or Y chromosome."

"Conception usually occurs when the ovum is in the outer third of the fallopian tube." Explanation: Conception usually occurs when the ovum is in the outer third of the fallopian tube (oviduct). Human life (conception) begins with the union of two cells: the ovum (female) and the sperm (male). At the time of conception, the sperm determines the sex. An ovum carries only one type of chromosome to determine sex: the X chromosome. A male sperm cell may carry either an X or Y sex chromosome. If a sperm cell carrying a Y chromosome fertilizes the ovum, a boy (XY) will result; if the sperm cell carries an X chromosome, the result will be a girl (XX).

The nursing student is preparing a presentation which will depict the pre-embryonic stage. The instructor determines the student has correctly illustrated the process by putting the stages in which order? Use all the options. 1 formation of the zygote 2 cleavage 3 formation of the morula 4 implantation 5 formation of blastocyte

1 formation of the zygote 2 cleavage 3 formation of the morula 4 formation of blastocyst 5 implantation Explanation: The pre-embryonic stage begins with fertilization and the formation of a zygote. Mitosis or cleavage occurs. After four cleavages, the 16 cells appear as a solid ball of cells or morula. With additional cell division, the morula divides into specialized cells, the blastocyst and trophoblast. The trophoblast attaches itself to the surface of the endometrium, and implantation occurs.

A woman has just learned that she is pregnant and would like to know how soon she can find out via ultrasound the sex of her fetus. The nurse should respond with which of the following? -At about 4 months -At about 2 months -At about 6 months -Fetal gender can only be determined by analysis of maternal serum

At about 4 months Explanation: Although fetal gender is usually determined by an ultrasound screen at about 4 months, it can be determined as early as 7 weeks by analysis of maternal serum.

The process of oogenesis begins before birth but is not complete until the childbearing years. At what point does the second meiotic division occur in this process? -At the time of fertilization by the sperm -At the time of division of the secondary oocyte and the first polar body -When the ovum attaches to the uterine wall -As the ovum is expelled from the corpus luteum.

At the time of fertilization by the sperm Explanation: The first meiotic division occurs before ovulation, forming a secondary oocyte and a polar body. The polar body disintegrates due to lack of cytoplasm. This leads to the second meiotic division as the sperm fertilizes the oocyte. The second division occurs long before attachment to the uterine wall, and after the division producing the polar body and as the ovum leaves the ovary.

A nurse is reviewing an article on genotypes. The nurse demonstrates understanding of the information by identifying which designation as homozygous dominant? -Bb -BB -XX -XY

BB Explanation: Homozygous dominant would be reflected in both alleles as the same and identified by an uppercase letter. Recessive alleles would be identified with a lowercase letter. X and Y are sex chromosomes, where XX would indicate a female and XY would be a male.

A client has learned that she is 4 weeks pregnant. The client states, "I don't see how that's possible. I'm sure that I had some bleeding almost exactly 4 weeks ago." The nurse should educate the client about what phenomenon? -Bleeding that sometimes accompanies implantation -The possibility that the client had a vaginal tear -The precision of pregnancy testing -Blastocyte formation

Bleeding that sometimes accompanies implantation Explanation: Implantation can sometimes cause a scant amount of bleeding, causing the client to misjudge the timing of pregnancy. The client would likely be very aware of a vaginal tear. Blastocyte formation has no relationship to this client's query. Similarly, teaching the client about pregnancy testing does not address her implied question.

The nurse is explaining the process of fertilization to a patient who has just learned of being pregnant. On which day during pregnancy should the nurse explain that the embryo implants on the uterine surface? -Four days after fertilization -Eight to 10 days after fertilization -The 14th day of a "typical" menstrual cycle -Ten days after the start of the menstrual flow

Eight to 10 days after fertilization Explanation: Implantation, or contact between the growing structure and the uterine endometrium, occurs approximately 8 to 10 days after fertilization. Four days after fertilization the structure is a zygote. Implantation does not occur on the 14th day of a typical menstrual cycle or 10 days after the start of a menstrual flow.

During which stage of fetal development is exposure to teratogens most damaging? -Pre-embryonic stage -Embryonic stage -Fetal stage -Mitosis stage

Embryonic stage Explanation: The most sensitive period of fetal development related to teratogens is during the embryonic period when the different body systems are developing. During the pre-embryonic stage, the fetal stage and the mitosis stage, the risk of teratogenic exposure is not as influential on the fetus.

A pregnant client is diagnosed with hydramnios. The nurse explains that further testing will be done to determine if which conditions are present? Select all that apply. -Esophageal atresia -Anencephaly -Renal atresia -Anuria -Fetal hypoxia

Esophageal atresia Anencephaly Explanation: Hydramnios or excessive amniotic fluid is found when the fetus has a condition such as esophageal atresia or anencephaly, which inhibit swallowing. Renal atresia or renal conditions that decrease urine production results in oligohydramnios. The volume of amniotic fluid protects the umbilical cord from pressure thus protecting the fetal oxygen supply.

Often, an ectopic pregnancy occurs in one of the woman's fallopian tubes. If undetected, the growing embryo puts extreme pressure on the tube, dilating it until it finally ruptures. Hemorrhage then occurs, putting the mother's life at risk. Where does the blood hemorrhage into? -Uterus -Peritoneal cavity -Rectum -Plural cavity

Peritoneal cavity Explanation: As the embryo grows in the confined space of the fallopian tube, it causes the tube to dilate. The tube will eventually rupture if the condition remains undetected. If the tube ruptures, hemorrhage into the peritoneal cavity can lead to maternal death.

The nurse is explaining the ultrasound procedure to a pregnant client and mentions part of the purpose is to evaluate the amniotic fluid. When questioned by the client how the amniotic fluid helps the fetus, which functions should the nurse point out? Select all that apply. -Provides physical protection -Helps regulates temperature -Produces necessary hormones -Provides unrestricted movement -Helps permit symmetrical growth

Provides physical protection Helps regulates temperature Provides unrestricted movement Helps permit symmetrical growth Explanation: Amniotic fluid fills the amniotic cavity. It serves four main functions for the fetus: physical protection, temperature regulation, provision of unrestricted movement, and symmetrical growth. The amniotic fluid does not produce hormones. Hormones are produced by the placenta.

The nurse is assessing a newborn infant for possible intrauterine growth restriction (IUGR). Which factor should the nurse analyze first to help determine if this diagnosis is accurate? -The mother's diet during the pregnancy -The ethnicity and stature of both the mother and father -Medication the mother took prior to conception -Inaccurate information to determine the due date

The ethnicity and stature of both the mother and father Explanation: The nurse should first ensure it is truly IUGR and not related to other issues such as the ethnicity and stature of both the mother and father, as some ethnic groups commonly produce offspring that are smaller than others. The diet, certain teratogenic medications, and incorrect due dates may contribute to the correct diagnosis of IUGR.

What physiologic changes occur after birth when the cord is cut and clamped? -The infant takes its first breath and the lungs expand to increase blood oxygen levels. - The ductus ovale closes over the next 2 to 3 days. -The oxygenated blood coming from the placenta is diverted around the liver through the ductus venosus. -The placenta is immediately expelled.

The infant takes its first breath and the lungs expand to increase blood oxygen levels. Explanation: As the infant takes its first breath, the pulmonary resistance decreases and blood flow increases to the lungs, resulting in increased oxygenation of the infant's blood. The ductus venosus and the ductus arteriosus close, not the ductus ovale. The foramen ovale normally closes when the pressure gradient in the heart shift from higher pressure on the right side to higher pressure on the left side of the heart. The placenta is not immediately expelled once the infant takes its first breath.

A nurse is conducting a prenatal class for expectant mothers and one of the mothers asks her how the placenta works. The nurse would explain that the placenta serves which purposes? Select all that apply. - The placenta provides nourishment for the fetus. - It serves as an exchange site for oxygen and carbon dioxide. -The placenta helps physically protect the fetus by surrounding the fetus with fluids. -It serves as a barrier to some medications and hormones in the maternal blood supply. -It releases insulin into the amniotic fluid for fetal usage.

The placenta provides nourishment for the fetus. It serves as an exchange site for oxygen and carbon dioxide. It serves as a barrier to some medications and hormones in the maternal blood supply. Explanation: The placenta serves three main functions: transfer and exchange of substances such as nutrients and waste products, production of hormones, and to act as a barrier to certain substances. It does not provide a physical protection to the fetus, not does it release insulin into the amniotic fluid for fetal use.

The nurse is conducting a presentation for a young adult community group about fetal development and pregnancy. The nurse determines that the teaching was successful when the group identifies that the sex of offspring is determined at which time? -during meiosis cell division -at fertilization -when the morula forms -during oogenesis

at fertilization Explanation: Sex determination occurs at the time of fertilization. Meiosis refers to cell division resulting in the formation of an ovum or sperm with half the number of chromosomes. The morula develops after a series of four cleavages following the formation of the zygote. Oogenesis refers to the development of a mature ovum, which has half the number of chromosomes.

After teaching a class on the various structures formed by the embryonic membranes, the nurse determines that the teaching was successful when the class identifies which structure as being formed by the mesoderm? -lungs -bones -ears -stomach

bones Explanation: The endoderm forms the structures of the respiratory system. The mesoderm forms the structures of the skeletal system. The ectoderm forms the structures of the special senses. The endoderm forms the structures of the digestive system.

A nursing student is explaining to a newly pregnant woman what happens during each stage of fetal development. At which stage does the nurse inform the woman that the lungs are fully shaped? -end of 4 weeks -end of 8 weeks -end of 12 weeks -end of 16 weeks

end of 16 weeks Explanation: At the end of 16 weeks, the lungs are fully shaped, fetus swallows amniotic fluid, skeletal structure is identifiable, downy lanugo hair is present on the body, and sex can be determined using ultrasound.

During a prenatal class for a group of new mothers, the nurse is describing the hormones produced by the placenta. What hormone would the nurse include? Select all that apply. -prolactin -estriol -relaxin -progestin -human chorionic somatomammotropin

estriol relaxin progestin human chorionic somatomammotropin Explanation: Estriol, relaxin, progestin, and human chorionic somatomammotropin are secreted by the placenta. Prolactin is secreted after delivery for breast-feeding.

An expectant mother is on heparin for previous blood clots and voicing concerns about how her medications will affect her baby. The nurse would inform the mother that: -heparin does not cross the placenta and is safe for her to take. -any medication that an expectant mother takes can cause sequelae for the infant. -she should discontinue the heparin and change to another anticoagulant. -it is recommended to stop taking the heparin while she is pregnant.

heparin does not cross the placenta and is safe for her to take. Explanation: Heparin is a medication that does not cross the placenta and therefore is safe to use during pregnancy. Not all medications cause fetal sequelae. It is not recommended to abruptly discontinue any medication without consulting the mother's health care provider and heparin is the safest anticoagulant for a pregnant woman to take.

A woman just gave birth to a healthy term newborn. Upon assessing the umbilical cord, the nurse would identify which structures as normal? Select all that apply. -one vein -two veins -one artery -two arteries -one ligament -two ligaments

one vein two arteries Explanation: The normal umbilical cord contains one large vein and two small arteries.

The nurse is providing prenatal care to a young couple who is pregnant with their first child. In what period of development would the nurse explain to the couple that most congenital defects would occur? -the period of the zygote -the period of the embryo -the period of the fetus -all periods are equally vulnerable

the period of the embryo Explanation: During the period of the embryo, which lasts until the eighth week after conception, the embryo is in what is called the critical phase of human development. During these weeks, all the organs and structures of the human are formed and are most susceptible to damage.