Fetal Development
What organ supplies oxygenated blood to the fetus?
placenta
What is the primary role of surfactant?
To reduce surface tension in the alveoli
because the are preferential nose breathers
What major event happens to the lungs during the first breath?
They expand and fill with air
what age is a neonate
birth-28days
Name the five stages of lung development
Embryonic, Pseudoglandular, Canalicular, Saccular, Alveolar
What type of cells produce surfactant?
Type II alveolar cells (pneumocytes)
Which fetal shunt connects the right atrium to the left atrium?
Foramen Ovale
What L/S ratio value indicates that fetal lungs are mature and ready for birth?
2:1 or higher
If the L/S ratio is less than 2:1, what condition is the newborn at high risk for?
Infant Respiratory Distress Syndrome (IRDS)
During which stage does the first surfactant appear?
Canalicular stage (24-26 weeks)
At what gestational age does surfactant production significantly increase?
Around 34-36 weeks
Which fetal shunt connects the pulmonary artery to the aorta?
Ductus Arteriosus
What provides the initial strong stimulus for the first breath?
temperature change and tactile stimulation
Which group of muscles do infants primarily rely on for breathing?
Diaphragm
Why are the fetal lungs bypassed in circulation?
Because they are fluid-filled and not used for gas exchange before birth.
What condition occurs due to a lack of surfactant in premature infants?
Infant Respiratory Distress Syndrome (IRDS)
Which fetal shunt connects the umbilical vein to the inferior vena cava?
Ductus Venosus
Name one difference in upper airway anatomy between infants and adults.
Infants have proportionally larger tongues and epiglottis is larger and less flexible
How many umbilical arteries and veins are present in the umbilical cord?
Two arteries, one vein
Which structure carries oxygenated blood from the placenta to the fetus?
Umbilical vein
Name one medication used to replace surfactant in premature infants.
Curosurf or Survanta
At birth the lungs hold about how much fluid and if low fluid what can happen
40ml/ cause hypoplastic lung
Why are infants at higher risk for airway collapse?
infants rib cage is more complaint making them more prone to airway collapse and retractions when in distress
The foramen ovale allows blood to flow directly from the ______ to the ______.
Right atrium to left atrium