Neonatal Physiology Flashcards
Describe the ductus venous and what vasculature it drains into?
bypasses the liver and drains into the inferior vena cava
continuation of the umbilical vein
Ductus arteriosus?
connects pulmonary artery with descending thoracic aorta
Relaxation of the smooth muscle layer of the ductus arteriosus is mediated by what?
PGE2
Describe where blood flow comes from to RA in neonatal system?
oxygenated (mixed) blood from IVC
deoxygenated blood from SVC
Where does the RA of the neonatal heart pump blood to?
to the LA (through the foramen ovale) mainly blood from IVC
To the RV- mainly blood from SVC
Where does the LA of neonatal heart receive blood from?
mixed blood (oxygenated and deoxygenated) from the RA (through the foramen ovale)
What chamber of the neonatal heart does the LA pump blood?
mixed blood into the LV
What are the factors/stimuli for initiation of respiration?
chemical (transitory hypoxia of fetus and neonates)
thermal
sensory and physical
mechanical
Describe the factors considered chemical stimuli (transitory hypoxia of fetus and neonates), that aid in the initiation of respiration?
Fetal factors:
Compression of umbilical cord
Changes in Maternal posture
Fall in maternal oxygenation (bearing down )
Neonatal factors:
Cessation of placental gas exchange
Cessation of umbilical cord pulsation
Cutting of the cord
Temporary asphyxia * respiratory center stimulated
How does thermal stimuli initiate respiration in the neonate?
Change in temp from intrauterine (98.6° F) to Extra uterine (70.75° F) , Excite nerve impulse in skin stimulate respiratory center
What are the sensory and physical stimuli that aid in causing the neonate to initiate respiration?
-Tactile stimuli—Touch
-Auditory –sounds- noise
-visual- Light
-respiratory center stimulated
Mechanical Stimuli
Compression of chest in birth canal
Sudden expansion (Recoil of chest wall) -ve pressure
Inspiration (mechanical suctioning)
What is the normal rate of respiration for the neonate?
30-50 breaths /min
Describe the normal breathing of a neonate.
Nature: diaphragmatic with some synchronization with chest movement
initially shallow and irregular
later ,deep & regular
Be able to map out cues (flow diagram) showing establishment of respiration for the baby.
What do the umbilical arteries form postnatally?
medial umbilical ligament