Respiratory embryo Flashcards
Separation of respiratory tract
Upper and lower
Upper respiratory tract parts
nose, nasopharynx, oropharynx and laryngopharynx
Lower respiratory tract parts
Larynx, trachea, bronchi, lungs
When is the respiratory system fully developed
After birth (alveolar sacs)
When does the respiratory system start to develop?
Begin during week 4, both upper and lower respiratory tract
Where does the respiratory system develop from?
The respiratory (laryngothracheal) diverticulum originates from the anterior wall of the foregut
What cells give rise to the internal respiratory epithelium and glands of the lower respiratory tract
The endoderm
What cells give rise to the CT, cartilage and smooth muscle of the lower respiratory tract?
The splachnic mesoderm (of the foregut)
Respiratory lung buds origin
Distal end of the respiratory diverticulum, appear as outpouchings
The respiratory diverticulum separates from the primordial pharynx by :
Tracheoesophageal septum, forming the laryngotrachea and the esophagus.
Foregut 3 portions:
Upper portion (respiratory diverticulum) Midgut (distal duodenum, jejunum, ileum, ascending colon & 2/3 of transverse colon) Hindgut (3/3 of transverse colon, descending colon, sigmoid colon & superior portion of rectum)
What is a trachea-esophageal fistula?
Incomplete separation or narrowing (atresia) of trachea and esophagus. Septum not formed correctly
Trachea-esophageal fistulas associated with defect in which of the three germ layers?
Mesoderm development.
Trachea-esophageal anormalities incidence
1/3000 births
Trachea-esophageal fistulas associated with
polyhydramnios(too much amniotic fluid) and regurgitate after feeding
The diaphragm develops from 4 embryonic components:
Septum transversum
Pleuroperitoneal membranes
Dorsal mesentry of esophagus
Muscular ingrowth from lateral body walls
The septum transversum grows ____ from the _____ body wall
Dorsally (front to back)
ventrolateral
Separates which two structures
Heart from liver, as it forms the central portion of the diaphragm.
The septum transversum is made up of
Mesodermal tissue
The septum transversum ____ separate thoracic and abdominal cavities
does not completly
The pericardioperitoneal cannals connect the:
Pericardial cavity with the peritoneal cavity
The septum fuses with the
Dorsal mesentry of the esophagus and the peluroperitoneal membranes.
The pleuroperitoneal membrane will
Cover the pericardioperitoneal canals separating the pericardium from the peritoneal cavity
Innervation of the septum transversum
Phrenic nerves
Congenital diphragmatic hernias are
deffects of the pleuroperitoneal membrane, the pericardial cannals do not close
More common on left side (bochdalek hernia)
Lung buds grow and as they grow what happen to the pleural cavities
The pleural cavities become smaller
The pericardioperitoneal cannal is the primordia of
The pleura cavities, only differnce is that the pleuropericardial folds separate the pericardium prom the pleura
Pleura cavity comes from____ and then forms the____
- Intraembryonic thelom/parietal mesoderm
- Parietal pleura
The lung buds are formed by the___, then grow and form the____
- splachnic mesoderm
- visceral pleura
Pattering of the lung into 2 primary brochi, which are:
Right (3 secondary bronchi) and left (2 secondary bronchi)
Maturation of the lung: pseudoglandular stage (week 5-16) 2 most important events are:
Terminal bronchi are formed, no alveoli
Maturation of the lung: canalicular period (weeks 16-26), 2 main events
Each terminal brochiole divide into 2 - 3 respiratory bronchioles
With 3-6 alveolar ducts, baby can survive
Maturation of the lungs: Alveolar period (8 month to childhood), important event:
Maturation of alveoli and capillaries
Maturation of the lungs: Terminal sac period (week 26 to birth), important event:
Terminal sacs(primitive alveoli) form, capillaries close contact
