Respiratory Embryo Flashcards
When does gas exchange happen in a baby?
Not until after birth (transitional circulation)
What layer is the lining of the respiratory system from?
endoderm
What are the muscle, cartilage, vessels, and connective tissue of the respiratory system from?
mesoderm
What is the nervous system part of the respiratory system from?
ectoderm
What is the lung bud?
Out-pouching from the ventral wall of the cranial portion of the endoderm (foregut)
What is the innervation of the larynx?
superior laryngeal and recurrent laryngeal nerves
What are the cartilage and muscles derived from in the larynx?
4th and 6th pharyngeal arches
Where does the larynx open into the pharynx? What part of the respiratory tree is the larynx?
Btn the 4th & 6th pharyngeal arches; larynx is most proximal portion of the respiratory tree
How are the trachea and esophagus divided?
Two ridges form to separate them - tracheo-oesophageal septum
What’s a tracheoesophageal fistula? What’s a fistula in general? What’s an esophageal
atresia?
A TEF is an abnormal connection (fistula) between the esophagus and the trachea. A fistula in general is an abnormal communication between two epithelialized surfaces. Congenital TEF can arise due to a failed fusion of the tracheoesophageal ridges during the 3rd week of embryological
development. VACTERL association.
Esophageal atresia - the esophagus ends in a blind-ended
pouch rather than connecting normally to the stomach
What is the VACTERL association with TEF?
Vertebral Anorectal Cardiac Tracheal Esophageal Radial/Renal Limb
The trachea buds into the right and left main bronchi in the 5th week. What do the right and
left main bronchi branch into?
R: 3 secondary bronchi, 10 tertiary (segmental) bronchi. L: 2 secondary bronchi, 8 segmental
bronchi
What are heterotaxy syndromes?
Heterotaxy syndrome is a disorder that results in certain organs forming on the opposite side
of the body. For example, instead of the heart normally forming on the left side of the chest, it
will be located on the right side. Heterotaxy has been known to affect the development of the
heart, liver, lungs, intestines, and spleen.
What’s in the pseudoglandular period (5-16 wks)?
Terminal bronchioles present
What’s in the canalicular period (16-26 wks)?
Respiratory bronchioles and alveolar ducts