Respiratory Dev.- Severson Flashcards
What cells are responsible for secreting pulmonary surfactant?
Type II alveolar cells
When does pulmonary surfactant BEGIN to form in the fetus?
20 weeks
When does pulmonary surfactant become SUFFICIENCY for a baby to survive?
24 weeks (says his practice questions)
26-28 (says his handout)
Where do Clara cells Goblet cells Type 1 pneumocytes and Type 2 pneumocytes develope from?
The epithelial component of the lung bud (respiratory diverticulum)
Congenital Lung cysts
formed by a dilation of terminal bronchioles due to a disturbance in bronchial development during late fetal life
Lungs have a honeycomb appearance
The lungs at birth are half inflated with liquid. What gives rise to this liquid?
Lung tissues
Describe the respiratory/laryngotracheal diverticulum
an endodermal outgrowth in the floor of the foregut
Where do the primitive pleural cavities originate from?
Pericardiperitoneal canals
Hyaline membrane disease (Respiratory Distress Syndrome)
Caused by a deficiency of pulmonary surfactant
injury to alveolar wall results in protein and fiberous rich exudation
What cells give rise to the cartilages of the larynx?
Neural crest mesenchyme!!!
Where does bronchial smooth muscle, cartilage in the bronchi, and pulmonary connective tissue arise from?
splanchnic mesenchyme
What is the most common congenital anomaly of the lower respiratory tract?
Tracheoesophageal fistula
What does laryngeal cartilage arise from?
Neural crest mesenchyme (ectoderm) of the 4th and 6th pharyngeal arches
Describe the difference between Type 1 and Type 2 pneumocytes
Type 1- 97% of alveolar surface. Line the alveoli. Squamous and THIN! Good for gas exchange
Type 2- secrete pulmonary surfactant
NOTE* Type II can serve as precuroses to Type 1 and other Type 2 cells. They proliferate during lung damage!!
HOW NEAT!
What part of the developing embryo does the respiratory diverticulum come from?`
Endoderm
What do the primitive pleural cavities originate from?
Pericardioperitoneal canals
Transesophageal fistula is frequently associated with what in regards to the esophagus?
Esophageal atresia = blind ending of esophagus, continues off the trachea
What causes eventration of the diaphragm?
Failure of cervical myotomes to migrate into the transverse septum
What causes oligohydraminos?
Bilateral renal agenesis (lack of urine production reduces the amount of amniotic fluid)
What 2 things may lung hypoplasia be associated with?
Congenital diaphragmatic hernia
Oligohydraminos
When do most of our mature alveoli develop?
Birth to age 8
What can you give in pregnancy to accelerate fetal lung development?
Glucocorticoids
What respiratory components arise from endoderm?
Epithelium and glands
of larynx, trachea, bronchi and pulmonary epithelium
What things arise from splanchnic mesenchyme?
Connective tissue
Smooth muscle (endothelial cells)
Cartilage
Where does splanchnic mesenchyme come from?
Myoblasts of 4th and 6th pharyngeal arch
Lungs at birth are 1/2 inflated with liquid, what gives rise to this liquid?
lung tissue
If an infant has a tracheoesophageal fistula, will you likely see polyhydramnios or oligohydramnios?
Polyhydramnios
Eventration of the diaphragm results from what?
Failure of cervical myotomes to migrate into transverse septum
What is ectopic cordis a result of?
Faulty development of sternum and pericardium
(secondary to incomplete fusion of lateral folds)
…so the heart is outside of the thorax!
What forms the central tendon of the diaphragm?
Septum Transversum!
When is do the alveoli completely mature?
Alveolar period of lung maturation = late fetal period to 8 years old
Describe the difference between Type 1 and Type 2 pneumocytes
Type 1- 97% of alveolar surface. Line the alveoli. Squamous and THIN! Good for gas exchange
Type 2- secrete pulmonary surfactant
NOTE* Type II can serve as precuroses to Type 1 and other Type 2 cells. They proliferate during lung damage!!
HOW NEAT!
What is a tracheoesophageal fistula?
Results from abnormal partitioning by the tracheoesophageal septus producing abnormal communication between the trachea and esophagus
What condition is most likely to be seen with a tracheoesophageal fistula?
Polyhydramnios = amniotic fluid accumulates
Transesophageal fistula is frequently associated with what in regards to the esophagus?
Esophageal atresia = blind ending of esophagus, continues off the trachea
What causes eventration of the diaphragm?
Failure of cervical myotomes to migrate into the transverse septum
What embryonic conditions leads to ectopic cordis?
Heart is found outside body
Fault development of the sternum and pericardium, secondary to incomplete fusion of the lateral folds
What can lead to the absence of the central tendon of the diaphragm?
The transverse septum failed to develope
Infant has left hypoplastic lung and herniation of abdominal intestines into the left thoracic cavity…. what failed to develop?
Pleuroperitoneal membrane
