Regarding physical growth of preschool children (3-5 years), all are true EXCEPT

Correct Answer: A

Rationale: The correct answer for this question is option A) 7-8 kg weight increment/yr is not true for preschool children (3-5 years). Option A is incorrect because preschool children typically gain around 2-3 kg (4.4-6.6 lbs) per year, not 7-8 kg. Rapid weight gain is more common in infancy than during the preschool years. Preschool children are usually more active and their growth rate slows down compared to infants. Option B is correct as children usually have around 20 primary teeth erupted by the age of 3 years. This is a normal developmental milestone for preschoolers. Option C is incorrect as brain myelination, the process of forming a protective sheath around nerves, continues well beyond 8 years of age. Myelination is a crucial process for the proper functioning of the nervous system and continues into adolescence and early adulthood. Option D is incorrect because the average height increment per year for preschool children is around 6-7 cm, not 5-6 cm. The growth rate varies throughout childhood, with a rapid growth spurt typically occurring during adolescence. In an educational context, understanding the typical growth and development milestones of preschool children is essential for healthcare professionals working with this age group. By knowing what is considered normal for this age range, healthcare providers can monitor children's growth, detect any deviations from the norm, and provide appropriate interventions if needed. This knowledge also helps in educating parents and caregivers about what to expect in terms of physical growth during the preschool years.

Correct Answer: D

Rationale: The correct answer is D) milk. Mercury is a toxic heavy metal that can be found in various sources. Swordfish, old teething powders, and quicksilver are all potential sources of mercury exposure. Swordfish is known to contain high levels of mercury due to bioaccumulation in large predatory fish. Old teething powders may have contained mercury prior to regulations banning its use in consumer products. Quicksilver is another term for elemental mercury, a common form of mercury found in certain products. In the context of pediatric health, it is crucial for healthcare professionals to be aware of potential sources of mercury exposure as children are more vulnerable to the harmful effects of mercury toxicity. Educating parents about these sources can help prevent accidental exposure and protect children from adverse health outcomes. Monitoring dietary intake, especially of fish known to have high mercury levels, and avoiding products like old teething powders can reduce the risk of mercury exposure in children.

Correct Answer: C

Rationale: The correct answer is C) 36 months old. This question assesses the developmental milestone of a child's fine motor skills and cognitive abilities. At around 36 months (3 years old), a child should be able to imitate construction of a bridge using 3 cubes, copy a circle, and make a tower of 10 cubes. This age signifies the stage of development where a child's fine motor skills, hand-eye coordination, and cognitive abilities have sufficiently progressed to perform these tasks. Option A) 24 months old is incorrect because at 2 years old, children typically do not have the fine motor skills and cognitive abilities to accomplish tasks as complex as building a tower of 10 cubes or copying a circle. Option B) 30 months old is also incorrect because although children at this age may start imitating construction of simple structures with blocks, they are unlikely to be able to copy a circle or make a tower of 10 cubes. Option D) 42 months old is incorrect as children at 42 months are typically more advanced in their fine motor skills and cognitive abilities than what is described in the question. By this age, they would be expected to perform more complex tasks than those outlined in the question. Understanding these developmental milestones is crucial for pediatric nurses as it helps them assess a child's growth and development, identify potential delays, and provide appropriate interventions or referrals when necessary. By knowing what is developmentally appropriate for each age group, healthcare providers can offer targeted support to promote optimal child development.

Correct Answer: D

Rationale: The correct answer to this question is D) formation of human embryo is about 6 weeks. Explanation: During embryonic development, the human embryo is typically formed by around 6 weeks after fertilization. This marks the end of the embryonic period and the beginning of the fetal period. By this time, major organ systems have started to develop, and the embryo has undergone significant growth and differentiation. Why the other options are wrong: A) Formation of ectoderm by 8 days: This statement is true. The ectoderm, which gives rise to the nervous system, skin, and other structures, is one of the first germ layers to form during embryonic development. B) Formation of mesoderm by 10 weeks: This statement is incorrect. The mesoderm, which develops into structures like muscles, bones, and circulatory system, is actually formed earlier, around 3 weeks after fertilization. C) Formation of endoderm by 3 cm crown-rump length: This statement is incorrect. The endoderm, which gives rise to the digestive system and other internal organs, is formed around the third week of gestation, not at a specific length measurement. Educational context: Understanding the timeline of embryonic development is crucial for healthcare professionals, especially those working in pediatrics. Knowing when different germ layers form and when major developmental milestones occur can help in assessing the growth and development of a fetus or newborn. This knowledge is essential for providing appropriate care and interventions for pediatric patients.

Correct Answer: C

Rationale: The correct answer is C) 24 months. This question assesses developmental milestones in a child, specifically focusing on language and motor skills. At around 24 months, a child is typically able to put three words together (subject, verb, object), demonstrate improved fine motor skills like handling a spoon well, and participate in activities independently. This age aligns with the expected developmental milestones for a toddler. Option A) 15 months is too early for a child to be able to perform the described tasks. At 15 months, children are still developing their fine motor skills and may not have the language capabilities to form three-word sentences. Option B) 18 months is also too early for a child to exhibit all the described skills. While some children may start putting two words together at this age, handling a spoon well and actively participating in dressing tasks are more commonly seen in older toddlers. Option D) 30 months is beyond the average age for these milestones. By 30 months, children should have already mastered these skills. Waiting until 30 months to achieve these milestones would be considered a developmental delay, requiring further evaluation. Understanding typical developmental milestones is crucial for healthcare providers working with children to monitor growth and development, identify potential delays early, and provide appropriate support and interventions when needed. This knowledge helps in promoting early intervention and optimizing outcomes for children.