Cardiorespiratory Adaptation At Birth Flashcards
What is required for the maturation of the fetal lung response to adrenaline?
Thyroid hormone and cortisol
At what week does the saccules develop in the alveolus?
24 weeks
On which receptors does adrenaline act on the apical membrane for chloride active transport?
B receptors
Why is a baby born by caesarean more likely to retain fluid in the lungs?
There’s no adrenaline rush or cortisol
Where is surfactant produced?
Type 2 pneumocytes - in the endoplasmic reticulum
Where is surfactant stored?
Lamellar bodies
Why do we need surfactant?
Reduces alveolar surface tension therefore deuces work to breathe
Makes sure alveoli doesn’t collapse
What is surfactant made up of?
Phospholipids
Neutral lipids
Protein
What are the 4 types of protein that surfactant is made of?
SP A
SP B
SP C
SP D
What is the function of SP A protein in surfactant?
Determines structure of tubular myelin
Stability and spreading of phospholipids
Negative feedback loops
What is SP B protein used for in surfactant?
Formation of tubular myelin
Spreading
Increases lung compliance in vivo
Protects surfactant film from inactivation by serum proteins
What does the SP C protein do in surfactant?
Significantly enhances adsorption and spreading on phospholipids
What is the function of SP D protein in surfactant?
Immune function
Which glucocorticoid enhances beta 2 receptor gene expression which leads to increased surfactant secretion
Dexamethasone
What does the thyroid hormones do in terms of surfactant?
T4 - increases surfactant production
TRH - increases phospholipid independent of T3 and T4
