Development of the respiratory System Flashcards
What do the spaces in the lateral plate mesoderm become?
The intraembryonic coelom
What does the primitive yolk sac give rise to?
- The gut tube
- The secondary yolk sac
- The viteline duct
What does the intaembryonic coelom become?
The body cavities
What does the somatic mesoderm line?
The wall of the thoracic cavity
What does the gut tube give rise to?
- Digestive system
- Accessory organs of digestive system
- Respiratory system
What is the gut tube formed from?
The endoderm
What is the respiratory diverticulum?
Develops from gut tube and grows anteriorly towards visceral layer of lateral plate mesoderm and also inferiorly
Develops into respiratory tract
What does the tracheo-esophageal ridge do?
Seperates the gut tube into foregut and respiratory diverticulum
Where/when do the laryngeal arches appear?
Cervical part of gut tube around week 4
How many pharyngeal arches are there?
5
What does each pharyngeal arch have?
- A cartiliginous element (develops into bone, ligament or cartilage)
- Aortic arch artery
- Its own nerve
What are the two swellings in the laryngeal orifice?
Epiglottal and laryngeal
What isthe small oriffice called that makes a connection between foregut and respiratory tract?
Laryngeal orifice
What does the endoderm develop into (in the respiratory system)?
Respiratory epithelium only
What does the mesoderm develop into (in the respiratory system)?
Cartilage, trachealis muscle etc.
What structures does the diaphragm develop from?
4 structures
- Pleuroperitoneal fold (posterolateral part of intraembryonic coelom)
- Septum transversum (anterior foetal wall)
- Mesentery of gut tube
- Abdominal muscle walls ingrow
What is the crus of the diaphragm developed from?
The mesentery
What happens if one of the structures which develop the diaphragm does not meet?
Diaphragmatic hernia occurs
What does the pleuropericardial fold contain?
Myoblasts from C3, 4, 5
Phrenic nerve
What is the most common congenital respiratory disorder
- Defect with tracheo-oesophageal ridge
- Gut tube becomes disconnected
- Proximal part of gut tube becomes atresic
- Distal part maintains connection with respiratory system
- 90% of disorders
What is the abnormal connection between the trachea and oesophagus called (congenital defect)?
Tracheoesophageal fistula (can cause pneumonitis from stomach acids)
What are the diaphragmatic hernias
- Bochdalek hernia
Posterolateral defect in fusion of pleuro-peritoneal folds
Most common
95% - Morgagni hernia (anterior, 2%)
- Central hernia (defect of septum transversum)
