Development of the Larynx, Trachea, and Lungs

Question 1

The respiratory system starts developing on the ……… week

Answer 1

4th week

Question 2

The cartilaginous, muscular, and connective tissue components of the trachea and lungs are derived from ………………….

Answer 2

splanchnic mesoderm

Question 3

The epithelium of the internal lining of the larynx, trachea, bronchi, and the lungs is entirely of ……….. origin

Answer 3

endodermal

Question 4

the ……………….. separate the lung buds from the foregut

Answer 4

tracheoesophageal ridges

Question 5

The respiratory primordium maintains its communication with the pharynx through the ………..

Answer 5

Laryngeal orifice

Question 6

tracheoesophageal ridges fuse to form the …………..

Answer 6

tracheoesophageal septum

Question 7

The internal lining of the larynx originates from …………..

Answer 7

endoderm

Question 8

the cartilages and muscles of the larynx originate from …………..

Answer 8

mesenchyme of the fourth and sixth pharyngeal arches

Question 9

When can the characteristic adult shape of the laryngeal orifice can be recognized?

Answer 9

when mesenchyme of the two arches transforms into the thyroid, cricoid, and arytenoid cartilages

Question 10

all laryngeal muscles are innervated by ………….

Answer 10

• branches of the tenth cranial nerve
• the vagus nerve

Question 11

the ……….. innervates derivatives of the sixth pharyngeal arch.

Answer 11

recurrent laryngeal nerve

Question 12

The ……………nerve innervates derivatives of the fourth pharyngeal arch

Answer 12

superior laryngeal nerve

Question 13

The trachea and bronchial buds are formed from …………….

Answer 13

The separation of the lung bud from the foregut

Question 14

The bronchial buds enlarge to form right and left main bronchi in the …….. week

Answer 14

5th week

Question 15

How many secondary bronchi are formed by th right and left main bronchi

Answer 15

The right main bronchi forms three secondary bronchi
The left main bronchi forms two secondary bronchi

Question 16

………….. develops into the visceral pleura.

Answer 16

The mesoderm (which covers the outside of the lung)

Question 17

How are the primitive pleural cavities formed?

Answer 17

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.

Question 18

…………… becomes the parietal pleura

Answer 18

The somatic mesoderm layer (covering the body wall from the inside)

Question 19

What is the pleural cavity?

Answer 19

The space between the parietal and visceral pleura

Question 20

How are the bronchopulmonary segments of the adult lung created?

Answer 20

secondary bronchi divide repeatedly in a dichotomous fashion, forming 10 tertiary bronchi in the right lung and 8 in the left

Question 21

The Pseudoglandular period extends from ……..

Answer 21

5th - 16th week

Question 22

Alveolar period of lung development extends from ……..

Answer 22

8 months - childhood

Question 23

The terminal sac period extends from ………

Answer 23

26th week to birth

Question 24

The canalicular period extends from ………….

Answer 24

16th - 26th week

Question 25

Up until the …………. prenatal month, the bronchioles divide continuously into more and smaller canals

Answer 25

7th

Question 26

What is the blood-air barrier composed of?

Answer 26

The intimate contact between epithelial and endothelial cells makes up the blood–air barrier

Question 27

………… produce surfactants

Answer 27

Type II alveolar epithelial cells

Question 28

What are surfactants?

Answer 28

phospholipid-rich fluids capable of lowering surface tension at the air– alveolar interface

Question 29

What is the role of surfactants in parturition?

Answer 29

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.

Question 30

What is atelectasis?

Answer 30

a complete or partial collapse of the entire lung or area of the lung.

Question 31

How do the lungs grow after birth?

Answer 31

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.

Question 32

What is the effect of absent or insufficienct surfactants in premature babies?

Answer 32

RDS
Respiratory distress syndrome occurs due to the collapse of the primitive alveoli, it is also known a hyaline membrane disease.