Respritory System And Thoracic Cavities Flashcards
The laryngotracheal groove and associated structures are comprise mainly of what and from where?
Foregut endoderm from the 6th primitive pharynx arch
When does the laryngotracheal groove form
Wk. 4
When does the tracheoesophageal folds complete the division into the tracheoseophageal septum
Wk. 5
An issue with the tracheoesophageal septum can gives rise to what disease
TEF
The laryngotracheal groove is derived from what
Foregut endoderm
What is the cartilage of the trachea is derived from
Splanchnic mesoderm
What does the epiglottis form from
The hypobranchial eminence
What is apoptosed during recanalizationm to allow passage between the vocal chords
Endoderm
When does recanalization take place and what does it form
Take place in week 10 and forms laryngeal ventricles and vestibular folds
Define laryngeal atresia. When does it occur, what is the clinical significance, and what causes it
Blockage of the upper airway. Also results in an inverted diaphragm and and fetal ascities (accumulation of serious fluid in the peritoneal cavity)
Occurs during the 10th week
Occurs due to a failure of recanalization (failure to apoptos the endoderm)
Baby needs immediate cric to survive
Define laryngeal webs. What causes it, what is the clinical significance, and how does it present
Is an incomplete atresia. The glottic opening is closed off with cartilage (endoderm) which fails to apoptose during recanalization
Presents as respiratory distress and stridor
Define laryngomalacia
A collapse of the supragolottic structures during inspiration
Is the most common abnormality of the larynx
The endoderm of the trachea gives rise to what
Epithelium and glands of the trachea
Pulmonary epithelium
The splanchnic mesenchyme of the trachea gives rise to what
Cartilage, connective tissue, and the smooth muscles
Define an esophageal atresia
A blind end esophagus - proximal esophagus stops while distal esophagus is joined with trachea via fistula
Happens in 84% of cases
Define tracheoesophageal fistula
An abnormal passage between the trachea and the esophagus
The bronchi and lungs grow into what
Pericardial peritoneal canals
At what week do the primary, secondary, and tertiary bronchi develop
Primary - wk. 5
Secondary - wk. 6
Tertiary - wk. 7
What happens during pseudoglandular stage and when is this stage
Terminal bronchioles form
Connective tissue forms
(5 - 17 weeks)
What occurs during the canalicular stage and when is it
16 - 25 wks.
Vascularization
Respiratory bronchioles gives rise to primordial alveolar ducts which give rise to terminal sacs (primitive alveoli)
What occurs during the terminal sac stage and when is it
24wks - birth
Gas exchange can occur here
Lymphatic capillaries form
Squamous epithelium differentiates into Type I pneumocytes
Secretory epithelial cells give rise to type II pneumocytes
What occurs in the alveolar stage and when is it
32 wks - 8yrs
Formation of alveolarcapillary membrane from endoderm and mesoderm
More primitive alveoli form
Mature alvioli form
What three things need to happen inorder for good lung development
- Fetal breathing movement
- Adequate thoracic space for growth
- Amniotic fluid
Define oligohydramnios
Very decreased amniotic fluid
Pulmonary hypoplasia may result (small lungs)
Splanchnic mesoderm gives rise to what in the airway
Cartilage
CT
Smooth muscles
Endoderm gives rise to what in the airway
Epithelium and the glands of trachea
Pulmonary epithelium
