NPS NPS Neonatal Physiology and Pathophysiology 2

Question 1

Why are preterm neonates at increased risk for hypoglycemia compared to term infants?

Accepted Answer

Limited glycogen stores and immature gluconeogenesis

Answer

Higher insulin secretion

Answer

Increased glucose uptake by brown fat

Answer

Maternal diabetes causing beta-cell hyperplasia

Question 2

Patent ductus arteriosus (PDA) in a preterm neonate creates a left-to-right shunt. Which organ is MOST at risk from increased blood flow?

Accepted Answer

Lungs

Answer

Kidney

Answer

Brain

Answer

Liver

Question 3

Retinopathy of prematurity (ROP) development is primarily driven by which pathophysiological mechanism?

Accepted Answer

Hyperoxia causing cessation of retinal vascularization followed by hypoxia-driven neovascularization

Answer

Direct light toxicity to the retina

Answer

Systemic hypertension causing retinal artery damage

Answer

Vitamin A deficiency impairing photoreceptor development

Question 4

A neonate has persistent metabolic acidosis with an elevated anion gap. Which condition should be suspected?

Accepted Answer

Inborn error of metabolism

Answer

Respiratory alkalosis from hyperventilation

Answer

Normal anion gap acidosis from diarrhea

Answer

Hypoalbuminemia

Question 5

Which physiological change explains the normal 'physiological jaundice' seen in healthy term newborns at 2–5 days of life?

Accepted Answer

Breakdown of fetal RBCs releasing unconjugated bilirubin exceeding immature hepatic conjugation capacity

Answer

Liver immaturity causing conjugated hyperbilirubinemia

Answer

Breastfeeding causing increased enterohepatic circulation only

Answer

Hemolysis from ABO incompatibility

Question 6

A newborn with trisomy 21 (Down syndrome) is found to have a large atrioventricular septal defect (AVSD). What is the most likely reason this lesion is particularly associated with trisomy 21?

Accepted Answer

Defects in endocardial cushion formation are common in trisomy 21

Answer

Gene on chromosome 21 directly causes cardiac malformation

Answer

Pulmonary hypertension prevents normal cardiac development

Answer

Thyroid dysfunction from trisomy 21 impairs heart formation