week 9- fetal chest, lung, diaphragm Flashcards
lungs begin developing in the __week gestation
5th
Name the stages of embryological lungs development and correlate them to appropriate gestational age?
- Embryonic (4-5 weeks)
- Pseudoglandular (5-17 weeks)
- Canalicular (16-26~28 weeks)
- Terminal saccular (26-36 weeks)
- Alveolar (36-term)
smooth muscle, cartilage, and Connective tissue originate from ___ layer
mesoderm
epithelial lining originate from the ___ later
endoderm
from the ___ the respiratory diverticulum forms and at the caudal end, the ___ is formed
foregut
lung bud
upper portion of ____ contributes to the trachea and larynx
respiratory diverticulum
___ forms the respiratory tree
lung bud
trachealesophageal folds fuse to form the
trachea-esophageal septum
trachea is ___ and esophagus is ___ (location)
ventral
dorsal
what forms the pleural cavity
pericardial peritoneal canal
parietal pleura is from the ____
somatic mesoderm
visceral pleura is from the ___
splanchnic mesoderm
bronchial buds form the R & L ____ bronchi that then divide and from ___ bronchi and then into ___ bronchi
primary
secondary
tertiary
bronchi that supply individual lobes
secondary
number of secondary bronchi on the right __ and left __
3
2
number of tertiary bronchi
10 on R and 10 on L
by week __ all bronchiopulmonary segments are formed
6
upper and lower respiratory system arise from
foregut
From what germinal layer do the lungs develop?
endoderm
From what structure do the lungs start to develop
caudal end of the respiratory diverticulum of the foregut
How does the echogenicity of the lungs compare to the echogenicity of the liver in 2nd trimester
lungs isoechoic to liver
How does the echogenicity of the lungs compare to the echogenicity of the liver in 3rd trimester
lungs slightly echogenic / hyperechoic
How we can assess the fetal lung maturity
amniocentesis to measure measure L/S Ratio (lecithin/sphingomyelin ratio) of amniotic fluid
How could lungs maturity be increased if C-Section is needed
give surfactant to increase maturity
stage where formation of the basic structure of gas exchanging portion of the lung develops (vascularization)
canicular (16-26 weeks)
stage where airways terminate in large smooth-walled cylindrical structures. subdivided by ridges called crests. Thinning of the interstitium
saccular stage (26-36)
Thinning of the blood-gas barrier, increased surfactant, and progressive branching of resp. airways
alveolar stage (36 weeks - term)
lungs medial border
heart
lung inferior border
diaphragm
lung lateral border
ribs
why do we assess the lungs
size, texture, location
phospholipoprotein produced by type II alveolar cells.
The main functionis to lower the surface tension at the air/liquid interface within the alveoli of the lung.
surfactant
surfactant level that indicates lung maturity
2-2.5
lungs develop ___ in pregnancy
late
34
> __ weeks lungs are mature
37
transitional age of lung maturity
34-47 weeks
low level of surfactant indicate
lungs are IMMATURE
later in pregnancy = more interfaces = ___ echogenicity
more
diaphragm appears as ___, __, ___, ___ (4) band
thin
hypoechoic
dome shaped
muscular
separates the abdominal cavity from thoracic cavity
diaphragm
what lobe of the liver is bigger in fetus
left
fetal lungs are more echogenic than the liver in ___ trimester
3rd
