Embryology

Question 1

What are the lower respiratory organs?

Answer 1

Larynx
Trachea
Bronchi
Lungs

Question 2

When does development of the lower respiratory organs begin?

Answer 2

Week 4 –> development of lung bud

Question 3

What gives rise to the epithelial lining of the larynx, trachea, and bronchi?

Answer 3

Endoderm

Question 4

What gives rise to the alveoli?

Answer 4

Endoderm

Question 5

What gives rise to the cartilage, smooth muscle, and CT of the respiratory organs?

Answer 5

Splanchnic mesoderm

Question 6

What is required for the appearance and development of the lung bud?

Answer 6

Increase in retinoic acid that upregulates transcription factor TBX4

Question 7

What develops into the tracheo-esophageal septum?

Answer 7

Mesoderm

Question 8

When do the primary bronchial buds develop?

Answer 8

Week 5

Question 9

What has occurred in lung development from wk 5 to wk 24?

Answer 9

Subdivisions of primary bronchi into secondary, tertiary, intrasegmental branchs and respiratory bronchioles

Question 10

What forms the parietal pleura?

Answer 10

Parietal/somatic mesoderm

Question 11

What forms the visceral pleura?

Answer 11

Visceral/splanchnic mesoderm

Question 12

How many additional divisions of the bronchial tree occur after birth?

Answer 12

6-7

Question 13

When do the pericardium, pleura, and peritoneum start to separate?

Answer 13

Wk 7

Question 14

What separates the pleural cavities from the pericardial cavity?

Answer 14

Pleuropericardial folds

Question 15

What separates the pleural cavities form the peritoneal cavity?

Answer 15

Pleuroperitoneal folds

Question 16

When is the pseudoglandular period?

Answer 16

Wks 5-16

Question 17

When is the canalicular period?

Answer 17

Wks 16-26

Question 18

When is the terminal sac period?

Answer 18

Wk 26 to birth

Question 19

When is the alveolar period?

Answer 19

Birth to 8 yo

Question 20

When does surfactant production start?

Answer 20

20-22 wks

Question 21

When does adequate amount of surfactant production occur?

Answer 21

After wk 32

Question 22

About how many of adult number of alveoli are present at birth?

Answer 22

1/6th

Question 23

What can be a result of oligohydramnios in lung development?

Answer 23

Hypoplasia of lungs

Question 24

What results from dilatation of terminal bronchioles in fetal life?

Answer 24

Congenital lung cysts

Question 25

What primarily contributes to the skeletal muscle of the diaphragm?

Answer 25

Myoblasts form cervical somites 3-5

Question 26

What develops into the crura of the diaphragm?

Answer 26

Dorsal mesentery of esophagus

Question 27

What causes congenital diaphragmatic hernia?

Answer 27

Failure of the pleuroperitoneal membranes to close the pericardioperitoneal canal

Question 28

What is the most commonly affected side in congenital diaphragmatic hernia?

Answer 28

Left