Pulmonary Embryology/Pediatric Lung disorders Flashcards Preview

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Flashcards in Pulmonary Embryology/Pediatric Lung disorders Deck (44):
1

lung tissue is derived from..

embryonic endoderm in the yolk sac

2

Pulmonary circualtion vessels is derived from

mesenchyme

3

Week 4

Lung bud moves ventrally into mesoderm "respiration diverticulum"
(primitive foregut epithelial cells invade splanchnic mesenchyme)

4

what happens Day 32?

laryngotracheal groove - out pouching between 4th and 6th brachial arch

5

Week 5

R and L lung buds push into the primordial pleural cavity

6

Wk 6

Descent into the thorax (lung and heart) until pleuroperitoneal foramen close

7

Week 7

descent halted by liver

8

Major events of Months 3-9

lungs grow (glandular)

9

Month 6

surfactant production

10

Month 7

respiratory bronchioles proliferate and alveolar ducts and sacs form

11

Outline of the stages

embryonic --> pseudoglandular --> Canalicular --> Saccular/terminal --> alveolar/postnatal

12

Embryonic

Week 4-7
Formation of the proximal tracheobronchial tree by branching of the foregut endoderm.
Formation from main --> lobar --> segmental (tertiary) --> subsegmental.
Occurs assymetrically and dichotomous

13

Disorders associated with embryonic stage dvmt issues

pulmonary agenesis
tracheoesophagel fistula
Vascular malformation to cause airway compression
Laryngomalacia

14

Pseudoglandular stage

Weeks 8-16
Formation until terminal bronchioles (but not alveoli).
Differentiation of conducting airway epitheilum
Splancnic mesoderm forms cartilage, Smooth muscle and mucus glands.

15

Canalicular

17-26 weeks
Formation of the respiratory bronchioles
Delineation of pulmonary acinus and initial development of pulmonary capillaries.
Beginning of fetal breating.
Survival is possible - but limited.

16

Diseases associated with canalicular stage

Pulmonary hypoplasia, potter's syndrome (decreased renal function), diaphragmatic hernia, RDS

17

Saccular/Terminal phase

26-36 weeks, or to term
growth and branching of sacs to increase in number. (alveolar ducts and terminal sacs)
Increase in vascularization! and epithelial differentiation to cause surfactant production increases

18

Alveolar/Postnatal phase

37 weeks to 3 yr
secondary septal formation and True Alveoli (90% occur after birth).
Continued formation of Type I from type II with lengthening of capillaries.
Alevoli thins

19

Pulmonary Arch and capillaries forms from..

6th aortic arch

20

Pulmonary veins form from

outgrowth of left atrium

21

Lungs/airways/chest in children vs. adults

Children have smaller airways - decreased radiance so larger resistance.
Larynx is more anterior and higher, large tongue, floppy epiglottis (for suck and swallow).
Smallest part is cricoid cartilage (adults is vocal cords)
Intercostal muscles are weaker
Diaphram is flat and easily fatigued due to type I muscles.
Increased compliant thorax (due to flat diaphragm)
Horizontal ribs

22

what does a increased compliant thorax mean for infants?

- decreased negative intrathoracic pressure and outward recoil
- decreased tidal volume -- prone to atelactasis.
ultimately cause less effective pump and easily fatigued.

23

PE signs of upper airway obstruction

Stridor, dysphagia, (drooling to avoid swallowing), dypsnea and distress.
No hypoxemia - that is a lower airway problem.

24

larygomalacia

Most common cause of stridor in kids.
Ineffective cartalaginous support of supraglottic structures.
Early presentation (before 6 months), worse with increase airflow or supine.
Outgrowth by 1 (female) or 2 (male)

25

tracheobronchomalacia

abnormal cartilage of trachea and bronchi to cause problems with exhalation.
increased secretion, recurrent wheeze, hoarse cough, and recurrent pneumonia.

26

Causes of Acute Stridor

Croup, Foreign Body, Epiglottitis, Bacterial Trachilitis

27

Croup

Laryngotracheobronchitis
Most common cause of acute stridor.
Viral and mild symptoms due to virus
Cough, low grade or no fever, NO drooling.
Treatment with steroids

28

Epiglottitis

A medical emergency cause of acute stridor.
Not seen often due to immunization of H influenza B.
Also with strep A and N. Gonnorhea or Hot liquid aspiration.
Occurs in older 2-7 year olds.
Associated with HIgher fever, drooling, dysphagia and low saturation
Tx: intubation and IV antibiotics

29

Bacterial Trachilitis

Acute stridor due to viral croup that progresses or staph aurea to cause edema and purulence.
High fever, normal epiglottis, in older kids.
recovery is longer than with epiglotitis.
Tx: intubation, debrdiement, suctioning, IV antibiotics.

30

Physical exam for lower airway disease

Hypoxemia, Wheeze, crackles

31

Bronchopulmonary dysplasia

decreased number of alveoli due to thickened interstitum and simplification of lung structure.
Defined as any baby that needs O2 after due date.

32

RDS vs BPD

RDS is a description of what happens when you are born. - whether at 27 weeks or 40.
BPD - use of oxygen after due date (40 wks).

33

causes of hypoxemia

VQ mismatch, hypoventilation, shunt, diffusion, extreme altitude, hemoglobinopathy

34

Causes of acute polyphonic wheeze

Bronchioloitis, viral pneumonia, CF, Heart disease, aspiration pneumonia, asthma

35

are you likely to grow out of asthma

no if you have eczema or allergies

36

Pneumonia causes for birth to one month

strep agulactiae and staph aureus

37

Pneumonia 1month - 5 years causes

strep pneumo

38

Pneumonia 5 y - 18 y

Mycoplasma

39

Tx for Px 1 -5 yrs

amoxicillin

40

what do babies do to prevent atelactasis and maintain minute ventilation

increase TV (retractions)
increase respiratory rate (tachypnea)
grunt to keep oxygen in lungs longer

41

Differentials for recurrent Px

immunodeficient, Aspiration Px, CF, airway anomalies, foreign body, TB, neuromucocilliary dysfunction

42

Poor growth is due to..

decreased absorption, decreased intake, increased WOB to cause increased metabolic demand

43

CF effects on lungs

Endobronchitis, bronchiectasis, fibrosis, inflammation, mucus plugging

44

Tx of CF

mechanical, antibiotics, DNase, bronchodilators, enzyme replacement, Fat soluble.