Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Neo boards > Respiratory Embryology, Devp > Flashcards

Respiratory Embryology, Devp Flashcards

(79 cards)

Start Studying
1
Q
A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Lung and airway development
- derived/arises from…
- type of morphogenesis
- morphogenesis depends on underlying…
- depends on many factors

A
  • resp tract derived from endoderm
  • lung forms from ventral bud of esophagus (FOREGUT)
  • branching morphogenesis
  • branching morphogenesis depends on mesodermal MESENCHYME
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Describe how lung development depends on:

  • morphogens
  • transcription factors
  • exogenous factors
  • growth factor (where is this made)

Recognize some of the factors involved in this lung development (chart)

A
  • morphogens
  • transcription factors: convert type II to I pneumocyte
  • exogenous: preterm birth, infection, vent days
  • growth factor: made by mesenchyme
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Describe development of pulmonary vascular system
- where does it form from
- larger bronchial arteries..from..supply..
- smaller pulmonary arteries supply..are complete by…

A

Pulm vasculature forms from branches off 6TH AORTIC ARCH

  • bronchial arteries - from aorta to conducting airways, visceral pleura, pulm arteries
  • small pulm arteries
    – preacinar arteries (angiogenesis) - up to nonresp bronchioles; complete at 16 weeks
    – intra-acinar arteries (vasculogenesis) - supply resp bronchioles ; and alveolar ducts; growth along w. alveolar devp until 8 - 10 years
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Name stages of lung development
- describe
- timing re GA
- abnormalities that can occur

A

Every Premie Can Suck Air

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Embryonic stage

A

Formation of:
Lung Bud, Trachea (28d)
Separation of the trachea and esophagus is complete
Left and right primary bronchus
Major airways (all 37 d)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Pseudoglandular stage

A

establish bronchial tree
pre-acinar bronchi
separation of pleuroperitoneal cavity pulm lymphatics
spec epithelial cells (from primary epithelial cells)

Also congenital lobar emphysema

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

CPAM vs BPS

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Cannalicular

A

Main events
*Formation of Pulmonary Acinus *Increase of Capillary Bed *Differentiation of Cuboidal Type II to squamous Type I cells (so start to secrete some surfactant)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Saccular

A

Main events
*Formation of Saccules
*Thinning of the Mesenchyme *Double Capillary Network in the septal walls
*Elastin deposition at secondary crests
*Fetal Lung Fluid Secretion**

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Alveolar

A

Main events
*Formation of alveoli by epithelial outgrowth
*Double Capillary Network fuses into a single layer
*Surfactant production increases in the Type II cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Alveoli Trivia (development)

When do most of alveoli form?

Number of alveoli at birth vs adulthood

How long do alveoli cont to develop

How long does lung surface area cont to grow

A

1st 6 months of life (when most alveoli form)

50 million to 300 million

2 to 8 years

18 years (squash court)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

The earliest stage of lung development, which is considered viable

A

cannalicular

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Respiratory Bronchioles are present earliest during

A

cannalicular

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Epithelial Differentiation is
* Centrifugal
* Centripetal
* Specific
* Locus-centric

A

centrifugal (inside-out)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Which protein is expressed at the FREE MARGIN of the MESENCHYMAL rings?

A

fibroblast growth factor eg FGF 10

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Mediators of Alveolarization

  • Positive mediators
  • Negative mediators
A

Positive
- Vit A, thromboxine
- fibroblast growth factor (from MESENCHYME) will direct development eg FGF10 (BIG in branching morphogenesis)

Negative
- post-natal steroids
- oxygen
- insulin
- ventilator

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

List some of the mediators of lung development

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Origin of major vessels of the lung

  • Pulmonary arteries
  • Pulmonary veins
  • Lymphatic vessels
A

PA - 6th pair of aortic arches
PV - outgrowth of LA
LV - cardinal vein

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Shaped like fried egg w. tight junctions

-which cells (type I vs II pneumocytes)
- how much of alveoli does it cover?
-stage of devp

A

Type I pneumocyte

  • role in gas exchange
  • derived from type II cells
  • covers 90% of alveoli surface (although less # of type I b/c flat so covers more surface with less #)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Cuboidal shaped pneumocytes
-which pneumocyte
-how much alveoli surface it covers
- role

A

Type II pneumocyte
- 10% of alveoli surface covered (but greater # of cells)
- role in surfactant metabolism and secretion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Composition of fetal lung fluid
- Cl high or low
- HCO3 high or low
- Protein high or low

A

Cl high
HCO3 and protein low

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Volume of fetal lung fluid produced hourly near term (similar to FRC at birth)

A

4 - 5 mL/kg/hour OR 20-30 mL/kg

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Describe fetal respirations and fetal lung fluid

A

Respiration -> larynx opens -> FLF slowly flows out of trachea -> this fluid either swallowed or mixes with amniotic fluid -> larynx closes -> helps lung maintain distended pressure (VITAL for lung growth)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
How is fetal lung fluid created?
Cl secreting channels in resp epithelium -> ACTIVE transport Cl across and into future air spaces -> osmotic gradient -> flow of liquid into lungs
26
How does epithelial cell transition (channels) to decrease fetal lung fluid production and increase its absorption
Cl secreting TO Na absorption channels (ENaC) -> Na into interstitium -> fluid follows
27
Amount of: - prenatal FLF clearance - during active labor FLF clearance - post-natal FLF clearance Describe how FLF occurs
35%, 30%, 35% Pre - less formed, Cl to Na channels, lymphatic oncotic P, low fetal alveolar protein Labor - mech forces, catecholamine, hormones Postnatal - lung distension, lymphatic oncotic P, low alv protein
28
Catecholamines and hormones that help with FLF clearance during labor
Catecholamines (increase transepithelial Na transport) Higher cortisol, higher thyroid hormone
29
Primary component of surfactant
mostly lipid 50% phosphatidylcholine desaturated + 20% PC mono + 8% surf proteins + 8% lipids + 8% PG
30
Most common cause of surfactant deficiency (genetic cause)
ABCA3 AR inheritance
31
Other Items Surf protein A,B,C,D - which are in exogenous surfactant - which cause disease, which most severe
B, C in exogenous Disease - A,B,C Involved in host defenses - A,D Most severe disease - Surf B defn B, C = critical esp B (tubular myelin formation)
32
surfactant production and secretion
* Stored as Lamellar Bodies (SPB, SP-C and lipids) * Secreted and then interact with SP-A to form tubular myelin * Recycled (almost 95%) * Some cleared by alveolar macrophages
33
Is the half life of surfactant longer in preterm babies? Why?
Recycling and turnover of surfactant takes longer. YES
34
Which surfactant proteins are hydrophilic? hydrophobic?
the hydrophobic surfactant proteins (SP-B and SP-C) play important roles in surfactant function and structure, and the hydrophilic surfactant proteins (SP-A and SP-D) in innate immunity, as well as in surfactant function (SP-A)
35
which surfactant protein is the most abundant?
surfactant A
36
*SP-B and SP-C are expressed early at the end of first semester *SP-D is expressed last (early third trimester) *SP-D is also present in many non-pulmonary cells *SP-B homozygous deficiency leads to the most severe respiratory failure at birth
Other Surfactant Factrs
37
Which of the following surfactant proteins are important in host defense?
A and D
38
Animal derived natural surfactants lack...
Surf A and D proteins
39
What metrics indicate lung maturity
L/S > 2 +PG (phosphatidylglycerol)
40
When does L/S = 2
35 weeks
41
When does % PG within amniotic fluid increase?
phosphatidylglycerol after 34- 35 weeks NOTE: not present in infants with RDS; those with resolving RDS will have increasing levels in lung.
42
L/S ratio of 2 and appearance of PG in amniotic fluid occurs by
35 weeks
43
Changes in surfactant with development
44
Surfactant secretion is increased by
Purines B agonists Lung distension
45
Term baby with severe RDS is negative for SP-B deficiency. Which other gene defect presents similarly?
ABCA3 deficiency
46
After you give surfactant to a baby with RDS the time constant
Increases
47
What changes first after surfactant administration? - oxygenation - compliance - ventilation Consider what happens to your P-V curve after surfactant
OXYGENATION! (compliance takes time). Think about hysteresis curve.
48
How do antenatal CS work?
* Induction of surfactant synthesis (types II pneumocytes to mature and cause differentiation of type II to I) * Increase surface area for gas exchange (making more surf, makes you recycle more surf!) * Improved response to postnatal surfactant *Also decreases: IVH, PDA, NEC and postnatal blood pressure
49
In experimental models, endotoxin is more effective than maternal betamethasone in inducing lung maturation
No? LPS is an endotoxin, can induce inflammatory cycle??
50
Recognize description of RDS CXR - what causes the described pattern
- groundglass - alveolar atelectasis - air bronchograms - open larger airways (increased aeration of these airways, increased resistance)
51
Surfactant administration decreases *Mortality * IVH * Symptomatic PDA * Sepsis * BPD
MORTALITY! but also has improved effect on all of the above
52
Describe La Place's law in the alveoli (surface T, P, r)
P = 2T / r
53
what influences delivery of surfactant positively? - volume of surfactant - rate of giving surfactant - vol of fetal lung fluid at the time of giving surfactant - GA of infant receiving surfactant
better to give more, faster, and when there is more fetal lung fluid (eg shortly after delivery)
54
Memorize - Genetic Lung Diseases Central hypoventilation syndrome (which mutation)
PHOX2B (paired like homeobox)
55
Memorize Genetic Lung Disease SFTPB - presentation
severe respiratory failure + PPHN
56
Memorize Genetic Lung Disease Forkhead box F1
Alveolar capillary dysplasia with misalignment pulmonary veins
57
NK2 Homeobox 1 (NKX2-1)
Interstitial lung disease thyroidtranscription factor gene mutation abnormalities of BG, thyroid gland and presents like surf deficiency
58
ABC3A mutation
Deficient in PG and DPPC | transport defect of lipids - so deficient DPPC, PG, lamellar bodies
59
60
61
Describes pathyphysiology of apnea of prematurity
DECREASE vent response to hypercarbia (increase TV rather than RR) - central IRRITATION of laryngeal mucosa (water, acid) -> INHIBITS breathing (mediated via superior laryngeal n) Response to hypoxic vent depression - centrally mediated in pons by INHIBITORY neurotransmitters lke adenosine (INHIBITS phrenic and hypoglossal nerve) - carotid body receptors - blunted response?
62
How do methylxanthines work for apnea of prematurity
Competitive ANTAGONIST of adenosine -- so inhibits adenosime Caffeine preferred - wider therapeutic index
63
CPAP for apnea of prematurity
increase FRC so increase baseline RESERVE of oxygenation to prevent apnea
64
REVIEW PAGE ON PPHN pathophysiology
increased PVR ->R to L shunt at atrial or ductal level -> decreased PBF -> hypoxemia
65
Factors that contribute to PPHN
Airway obstruction/atelectasis Inflammation - increase platelet activation, leukotrienes, thromboxane Pulm hypoplasia Mat meds - indocin, aspirin, tylenol Acidosis, hypoxia
66
PPHN - describe with ex maldevelopment vs maladaptation
Maldevp - PV bed abnormal in structure or size - SM hypertrophy with FGR, fetal ductal closure; decreased cross sectional area CDH, pulm cap dysplasia, ELBW Maladapt - normal pulm vasc bed - pna, MSAF, sepsis, amniotic fluid aspiration, perinatal depression
67
PPHN clinical presentation
hypoxemia +/- hypercarbia, pre-post spot 20% (except if there is significant atrial mixing)
68
PPHN management - evaluation - medications - optimize cardiac functioning
ECHO to rule out CHD, may see bowing of IV septum into RV, shunting R to L O2, surf (depending on etiology), correct TEMP, correct ACIDOSIS, Euglycemic! pRBCs Maybe inotropes to increase SVR - may help with improving L to R shunting (even driving SBP a bit higher than usual)
69
iNO - evidence FDA - explain how it works
Selectively dilates pulm vessels that are VENTILATED evidence that it enhances oxygenation, decreases ECMO - for term. FDA approved for PPHN for > 34 weeks Careful of rebound pulm vasoconstriction after discontinuing
70
Action of sildenafil
PDE5 inhibitor - PDE (phosphodiesterase) 5 hydrolyzes cGMP to GMP -> inhibits THIS so that there is prolonging effect of cGMP (which vasodilates in pulm arteries) see change by about 2 weeks, titrate to try and avoid hypotension NOTE: phosphodiesterases block the action of cGMP (cGMP increases Ca efflux for vascular SM relaxation) --> so want to inhibit these PDEs
71
Action of milrinone
PDE 3 inhibits PDE 3 which hydrolyzes cAMP to AMP
72
PPHN and BPD
vascular remodeling -> pruning vascular tree -> with decreased microvessel density and decreased blood flow area
73
74
A Note - B is normal
75
what can delay alveolarization
76
77
Histopatho old vs new BPD
78
D
79
E

Neo boards (14 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions