w7- lung devo Flashcards
if the ventral wall fails to fuse, what connection will be maintained and what condition would this result in
connection between the intra and extra-embryonic coelom
would result in ectopic cordis
what does the septum transversum form
where is it derived from
central tendon and the connective tissue of the liver
derived from visceral so the splachnic mesoderm of the lateral plate
what divides the:
coleum
the thoracic and the peritoneal cavity
pericardial and the pleural cavity of the thoracic
the pleural and the peritoneal cavity
septum transversum
pericardoperitoneal canal
pleuropericardial membrane
diaphram
what forms the fibrous pericardium
pleuropericardial membranes
what 4 structures make the diaphragm
what condition can occur if it does not fuse properly
(1) septum transversum, (2) esophageal mesentery, (3) pleuroperitoneal membranes, and (4) muscle
the pleuroperitoneal membranes are overlayed by central musculature of diaphragm from C3-5
body wall mesenchye forms the peripheral musculature innervated by T7-T12
congenital diaphragmatic hernia (CDH).
what are the three places that hernias form in CDH
what is CDH often associated with
sternal, esophageal, and posterior regions
posterior are most common
esophageal hiatus–> stomach in pleural cavity
left pleuropericardial membrane –> intestines in pleural cavity
pulmonary hypoplasia
where does the respiratory diverticulum derive from
how is it seperated from the foregut
what happens if this fails
Respiratory diverticulum pouches off of foregut endoderm from floor of primordial pharynx
tracheoesophageal ridges –> This septum results in the formation and separation of the esophagus and the laryngotracheal tube
TE fistula
what other conditions is TEF often associated with
VATER
vertebral defects
anal atresia
TEF
renal dysplasia
what is the psuedoglanular phase characterized by
formation and growth of the respiratory conducting zone , resulting in the formation of terminal bronchioles within the bronchopulmonary segments
what is the earliest stage life is viable
the canalicular after 20 weeks when surfactant production begins
what occurs in the cannalicular phase
formation of vascular beds. (VEGF), respiratory bronchioles and terminal sacs (primitive alveoli), and surfactant
•Lung epithelium differentiatesinto specialized cells types.
when are type I and II pneumocytes fully differentiated
saccular stage
surfactant low until 24 weeks
what occurs in alveolar stage
lung size increases due to maturation of alveoli, secondary septationand remodeling and maturation of tissues
: It doesn’t end there—the lungs continue to grow and mature until age 18.
what determines fetal lung growth
fetal lung volume –> secrections and movements
- Fetal respiratory movements (FRM) or fetal breathing movements (FBM) are regular muscular contractions occurring as early as the 10thweek.
- Amniotic fluid, produced by maternal plasma as well as fetal kidneys, is breathed into the lungs and is critical for proper lung development.
- Distention of fetal lungs by fetal lung fluid is related to hyperplasia of the lung; drainage or lack of fluid results in pulmonary hypoplasia
Thus, fetuses with kidney anomalies or other conditions that result in oligohydramnios often present with hypoplastic lungs.