Development of the respiratory System Flashcards
What happens in Week 3 embryonic development
Oropharangeal membrane forms on the dorsal surface of the anterior region.
cloacal membrane forms on the dorsal surface of the posterior region.
What happens to to the oropharyngeal membrane in week 4
The oropharngeal membrane breaks down in week four to connect to the oral cavity to the pharynx and the GI tract.
What happens to the cloacal membrane
It breaks down forming the openings of the anal, urinary and reproductive tract.
What happens to the embryonic folding in week 4
Causes unequal grownths rates at different parts.
What does folding in the medial plane give
Head and tail
What does the lateral folds form
coelom and pinches off the yolk sac giving rise to the primitive gut.
What is the primitive gut make up of
Foregut, the midgut and the hind gut
What does folding cause
It cause the pharyngeal arches to develop on either side of the head and internal pharngeal pouches.
When does the lung bud appear and what stage
Week 4 the lung bud and respiratory diverticulum appear as outgrowths from the ventral wall of the foregut.
What happens to the lung bud in its early staged.
Has a similar opening to the foregut but as it starts to extend it becomes separated from the foregut by the oesophageal rises.
What does the oesophageal ridges fuse with
They fuse with oesophageal septum which then divides the foregut into a dorsal region which is the oesophagus and the ventral region which is the trachea.
What is the lining of larynx made up of
Endodermal
What is the lining of the muscles and cartilage made up of
Mesenchymal cells
Where do mesenchymal cells arise from
4th and 6th pharyngeal arches.
What do the pharyngeal arches differentiate into
Thyroid, arentonid and carotid cartilages.
How are mesenchymal cells used to develop the larynx
They divide inducing the larnageal opening to change from a simple split to a T Shaped opening.
What happens to laryngeal cartilages
they form the laryngeal epithelium which proliferates and temporal blocks the lumen of the deverticulum.
How are the trachea and bronchi developed.
The diverticulum separated from the foregut forming two lateral branches to form the right and left primary bronchi by week 5
How are the lungs developed
pericardioperitineal canals are found either side of the foregut and they fill.
formation of the type 1 and type 2 cells form.
what is oesophageal atresia and tracheosesophageal fistula
Abnormal portioning of oesophagus and the trachea.
Oesophageal atresia the oesophagus terminates in. a blind ended passage
TEF abnormal openings forms between the oesophagus and the trachea.
What are congenital cysts
Abnormal budding of the diverticulum, resulting gin dialled and poorly vascualrised terminal or larger bronchioles.
What is respiratory distress syndrome
Insufficent quantities of surfactant are produced.
Most common causes of death in premature infants.
Collapse alveoli may become filled with a protein rich fluid and may from what ae known as hyaline membranes.
