Development of the Larynx, Trachea, and Lungs Flashcards
The respiratory system starts developing on the ……… week
4th week
The cartilaginous, muscular, and connective tissue components of the trachea and lungs are derived from ………………….
splanchnic mesoderm
The epithelium of the internal lining of the larynx, trachea, bronchi, and the lungs is entirely of ……….. origin
endodermal
the ……………….. separate the lung buds from the foregut
tracheoesophageal ridges
The respiratory primordium maintains its communication with the pharynx through the ………..
Laryngeal orifice
tracheoesophageal ridges fuse to form the …………..
tracheoesophageal septum
The internal lining of the larynx originates from …………..
endoderm
the cartilages and muscles of the larynx originate from …………..
mesenchyme of the fourth and sixth pharyngeal arches
When can the characteristic adult shape of the laryngeal orifice can be recognized?
when mesenchyme of the two arches transforms into the thyroid, cricoid, and arytenoid cartilages
all laryngeal muscles are innervated by ………….
- branches of the tenth cranial nerve
- the vagus nerve
the ……….. innervates derivatives of the sixth pharyngeal arch.
recurrent laryngeal nerve
The ……………nerve innervates derivatives of the fourth pharyngeal arch
superior laryngeal nerve
The trachea and bronchial buds are formed from …………….
The separation of the lung bud from the foregut
The bronchial buds enlarge to form right and left main bronchi in the …….. week
5th week
How many secondary bronchi are formed by th right and left main bronchi
The right main bronchi forms three secondary bronchi
The left main bronchi forms two secondary bronchi
………….. develops into the visceral pleura.
The mesoderm (which covers the outside of the lung)
How are the primitive pleural cavities formed?
the pleuroperitoneal and pleuropericardial folds separate the pericardioperitoneal canals from the peritoneal and pericardial cavities, respectively, and the remaining spaces form the primitive pleural cavities.
…………… becomes the parietal pleura
The somatic mesoderm layer (covering the body wall from the inside)
What is the pleural cavity?
The space between the parietal and visceral pleura
How are the bronchopulmonary segments of the adult lung created?
secondary bronchi divide repeatedly in a dichotomous fashion, forming 10 tertiary bronchi in the right lung and 8 in the left
The Pseudoglandular period extends from ……..
5th - 16th week
Alveolar period of lung development extends from ……..
8 months - childhood
The terminal sac period extends from ………
26th week to birth
The canalicular period extends from ………….
16th - 26th week
Up until the …………. prenatal month, the bronchioles divide continuously into more and smaller canals
7th
What is the blood-air barrier composed of?
The intimate contact between epithelial and endothelial cells makes up the blood–air barrier
………… produce surfactants
Type II alveolar epithelial cells
What are surfactants?
phospholipid-rich fluids capable of lowering surface tension at the air– alveolar interface
What is the role of surfactants in parturition?
As concentrations of surfactant increase during the 34th week of gestation, some of this phospholipid enters the amniotic fluid and acts on macrophages in the amniotic cavity. Once “activated,” these macrophages migrate across the chorion into the uterus where they begin to produce immune system proteins, including interleukin-1B (IL-1B). Upregulation of these proteins results in increased production of prostaglandins that cause uterine contractions.
What is atelectasis?
a complete or partial collapse of the entire lung or area of the lung.
How do the lungs grow after birth?
Growth of the lungs after birth is primarily due to an increase in the number of respiratory bronchioles and alveoli and not to an increase in the size of the alveoli.
What is the effect of absent or insufficienct surfactants in premature babies?
RDS
Respiratory distress syndrome occurs due to the collapse of the primitive alveoli, it is also known a hyaline membrane disease.
