Respiratory Day Flashcards
from Pediatrix review (119 cards)
ENaC is inhibited by what
Amiloride
Fetal lung fluid and aminoic fluid
lung fluid go to aminoic fluid but amnioci fluid don’t go to lung (small)
amount of FLF secreted daily
250-300ml/day in human (4-5ml/kg/hr in near term infants)
20-30ml/kg, similar to FRC.
pressure gradient 3-5 cm H2O across laryn. –> CPAP volume.
secretion FLF:
inhibit by what
Driven by what molecule
inhibit by: Bumetanide, beta adrenergics, vaspressin, epinephrine
Na-K-2Cl Tri-transporter and Chloride
channels (ClC2, CLCN2)
Cl
absorption of FLF by what channel
Driven by what molecule
inhibited by what medications?
Epithelial Na Channel (ENaC) (face alveolar lumen)
Na-K-ATPase (face blood)
Na
Inhibited by Amiloride.
Na-K-ATPase inhibited by Ouabain
FLF composition
rich in Na
rich in Cl
protein content is ZERO –> allow the fluid to be absorbed after birth
low bicarb
very acidic
FLF Clearance
Before Birth
During Labor
After Birth
35% cleared during days prior to birth (decrease secretion of FLF through decrease Cl secretion, increase Na transport from alveolar space, increase lymhatic oncotic pressure)
30% cleared during labor:
- ENac Channel, active Na absorption
From catecholamine surge, higher cortisol and thyroid hormone
- mechanical force compresse fetal chest
- epinephrine suppress FLF secretion (cl channels)
35% cleared postnatally: lung distention (↑transpulmonary pressure), ↑ Lymphatic oncotic pressure associated with low fetal alveolar protein, crying.
Fetal Breathing Movement
( not a good card)
occurs in discrete episode (resemble REM sleep in periods of low voltage crotical activity)
principle musles: diaphgragm and glottis.
later half of gestation 40-50% FBM alternates with complete apnea.
without breathing movement, lung cannot grow.
REM sleep in baby
(not a good card)
irregular breathing
loss of upper airway and intercostal muscle activity, leading to a greater risk of airway obstruction
what causes bradycardia after birth
(Maybe not a good card)
lack of pulmonary stretch
Asphyxia -> hypoxia -> carotid chemo-rectorps -> bradycardia.
In addition:
Periglottic stimulation -> laryngeal reflex (tickle vocal cord with suctioning, vocal cord close)
Lung inflation and vagal tone
lung inflation, -> decrease vagal tone -> increase heart rate
What are these respiratory reflexes:
Hering-Breur inflation Reflex
Parodoxical reflex of head
Hering-Breuer Deflation Relex
J receptor reflex ?
Hering Breur Reflex: Lung over-inflation leads to cessation of inspiration. Protective. increase with GA, strongest in first few months. NB>Adults (via pulmonary stretch receptor (on airway smooth muscle > medulla > vagal nerve )
Parodoxical reflex of Head
* Inhibition of Hering Breur reflex results in extended inspiration. initial NB breaths in term infant (parodoxical increase in diaphgramatic contraction during inflation)
* probably important in causing periodic deep sighs breath.
Hering-Breuer Deflation Relex:
increase in ventilatory rate with abrupt deflation of the lungs (i.e. pneumothorax)
associated with deep sign breath.
Help maintain FRC in infant’s
J Receptor Reflex: Juxta capillary receptors; Rapid shallow breathing (can be dissociated from chemoreceptor)
iNO
where does it come from and how does it work?
Arginine becomes NO (nitric oxide, using NO synthase)
iNO convert GTP -> cGMP (guanyl cyclase)
cGMP -> K+ channels -> vasodilation
Sildenafil block PDE5, whcih break down cGMP.
PDE5 = phosphodiesterase 5
what’s most rapidly depleted in neuronal injury and cell death.
Phosphocreatine most rapidly depleted
apoptotic cell death
vs.
necrotic cell death
caspases (in apototic cell death)
Cytochrome c released from mitochondria
activates caspase-8 & caspase-9
Initial hypoxia and glucose deprivation disrupts cellular
homeostasis and ATP depletion
* Loss of Na-K-ATPase, membrane depolarization, influx
of Na, Ca, and H2O
* Excess extracellular glutamate increases Ca entry
* Phospholipases, Xanthine oxidase, nNOS
* Cell swelling and death
what are some of scavengers (or lack of scanvengers) in oxidative stress
(might not be important?)
Lack of scavengers:
glutathione, SOD, catalase,
cholesterol
Radicals with unpaired electrons react with proteins, lipids and DNA producing oxidative damage
inflammatory damage from chorioamnionitis is due to what chemicals
release of cytokines like IL-6, IL-8, interferon gamma as well
(cause iNO production, vasodilation, capillary leak)
Temporal relationship to CP
Prolonged intrauterine hypoxia shows up as what in the cord gas
profound metabolic acidosis
BE high.
what stage in lung development is consider viable
canalicular
primitive alveoli = respiraotry bronchioles
lung buds is from what germ layer
endoderm
pulmonary arteries originated from what?
Pulmonary vein originated from what
6th pair of aortic arches
(also where PDA comes from, the 6th left arch, same as L pulmonary artery)
left atrium
Airway development under control of what signaling
Airway development under control by retinoic acid signaling
In pseudoglandular phase, what gene/signaling pathway control development
*Early branching is regulated by the insulin-like growth factor
*Cellular differentiation (ciliated, goblet, basal) under the control of FGF-10 and FGF-7
*Disruption of FGF-10 results in lung agenesis
*Excess FGF-7 leads to poor differentiation, resembles CPAM
*Mutations on FGFR2 –Pfeiffer, Apert, Crouzons – variety of defects (laryngomalacia, tracheomalacia, lobar atresia, pulmonary aplasia)
*Note: *FGFR3 = achondroplasia
what disease happened during Embryogenic stage of lung development
TEF
tracheal stenosis
laryngeal cleft
Bronchiogenic cyst