Anatomy and Physiology Flashcard 2

B. Rationale: The fetal alveolar sacs are filled with fluid and are inefficient for gas exchange in utero. Placental circulation between the mother and the fetus facilitates gas exchange, and thus it is necessary to bypass the fetal pulmonary vasculature. Fetal circulation must adapt through the right-to-left shunts. Temporary anatomic shunts make this possible during fetal life, and they close when there is a transition from fetal circulation to neonatal circulation.

B. Rationale: Chest compressions must be applied toward the lower third of the sternum, which optimally compress the heart against the spine and cause an increase in aortic pressure and right atrial pressure. When the chest is decompressed with full chest recoil, the right atrial pressure decreases faster than the aortic pressure. The resulting pressure gradient will cause blood to flow into the coronary arteries, perfusing them with oxygenated blood.

D. Rationale: The newly born is at risk of mortality, encephalopathy, and seizures if a mother in labor has a fever. On the other hand, maternal hypothermia during labor does not seem to pose a problem to the fetus or affect neonatal outcomes during birth.

C. Rationale: Pulmonary hypertension is a consequence of persistently constricted pulmonary vasculature after transitioning to extrauterine life, commonly seen in newly born infants > 34 weeks gestational age.

A. Rationale: When a baby is born, there is a significant amount of blood volume in the placenta, enough to continue gas exchange and blood flow in the first minutes of life postpartum. Delaying cord clamping allows this blood to circulate, delivering increased blood volume to the infant.

A. Rationale: The immature blood vessels in the preterm, especially in the brain, are sensitive to changes in blood pressure, which can be damaged and cause extravasation of blood, especially in the interventricular region of the brain. Aside from disturbances in the cerebral blood flow, intraventricular hemorrhage originates from the intrinsic fragility of the germinal matrix vasculature due to an abundance of angiogenic blood vessels.

B. Rationale: The gas exchange between the mother and the fetus occurs via placental respiration. The transition to pulmonary respiration happens after live birth when the newly born takes the first breath.

B. Rationale: Vital structures such as the nerves and blood vessels are situated in the inferior aspect of the rib, particularly in the costal groove. These structures are avoided when the catheter is directed above the rib.

A. Rationale: NRP focuses on establishing adequate ventilation rather than starting chest compressions. Most newly born’s that require resuscitation have a healthy heart. The common problem in neonates is respiratory failure with impaired gas exchange, and ventilation is a priority.

C. Rationale: The epiglottis is a flap made up of elastic cartilage that covers the glottis and prevents food material and water from entering the lower airways.