Development of the Respiratory system

Question 1

Which germ layer forms the epithelium of the whole respiratory passage

Answer 1

Endoderm

Question 2

Which germ layer forms the cartilaginous, muscular & connective tissue components of the larynx, trachea, and lungs

Answer 2

Mesoderm

Question 3

The respiratory system begins development during which week of embryonic development

Answer 3

Week 4

Question 4

Which wall of the foregut does the respiratory diverticulum (lung bud) arise from

Answer 4

Ventral wall of the foregut

Question 5

An increase n which chemical upregulates the transcription factor for lung bud development

Answer 5

Retinoic acid

Question 6

Retinoic acid upregulates which transcription factor in lung development

Answer 6

TBX4

Question 7

Which layer of the foregut is TBX4 (needed for lung development) expressed

Answer 7

Endoderm

Question 8

During which weeks is the critical time for lung development

Answer 8

25-28th week

Question 9

The tracheoesophageal septum divides the forgut into what ventrally and what dorsally

Answer 9

The trachea ventrally and the esophagus dorsally

Question 10

Which structure allows for the communication between the lung bud and the pharynx

Answer 10

laryngeal orifice

Question 11

The muscle and cartilage of the larynx is derived from which pharyngeal arch(es)

Answer 11

4th and 6th pharyngeal arch

Question 12

Transformation of the 4th and 6th pharyngeal arches into which 3 cartilages form the adult shape of the larynx

Answer 12

Thyroid, cricoid and arytenoid cartilages

Question 13

Three and false vocal cords originate from which embryonic structure

Answer 13

A pair if lateral ventricles

Question 14

Improper formation of tracheoesophageal septum can result in which condition

Answer 14

Tracheoesophageal fistulas

Question 15

What other two conditions result due to Tracheoesophageal fistulas

Answer 15

esophageal atresia & polyhydramnios

Question 16

What can result due to esophageal atresia & polyhydramnio

Answer 16

excessive accumulation of saliva/ mucus in the nose and mouth, episodes of gaging, & cyanosis after swallowing milk, abdominal distension after crying, reflux of gastric contents into the lungs causes pneumonitis/pneumonia

Question 17

At which week does the limb buds form the right and let main bronchi

Answer 17

5th week

Question 18

Which layer of the lateral plate mesoderm forms –parietal layer of pleural cavity

Answer 18

Somatic layer

Question 19

Which later of lateral plate mesoderm forms – visceral layer of pleura

Answer 19

Splanchnic layer

Question 20

Which condition presents with a honeycomb appearance on a radiograph

Answer 20

• Congenital bronchial cysts (bronchiectasis)

Question 21

What are the three period of lung maturation

Answer 21

Pseudo glandular period

Canalicular period

terminal sac period

alveolar period

Question 22

Which type of alveolar epithelial cells secrete surfactant

Answer 22

Type II

Question 23

babies born during which period of lung maturation cannot survive because respiration is impossible

Answer 23

pseudoglandular phase

Question 24

How long does the Pseudo glandular period

last

Answer 24

5-16th week

Question 25

How long does the Canalicular period last

Answer 25

16-26th week

Question 26

How long does the Terminal sac period last

Answer 26

26th week to birth

Question 27

How long does the Alveolar period last

Answer 27

8 month to childhood

Question 28

When does surfactant increase the most during embryonic life

Answer 28

Last 2 weeks before birth

Question 29

What is the function of surfactant

Answer 29

to prevent collapse of the alveoli

Question 30

Growth of which 2 structures after birth is responsible for the increase in size of the lungs

Answer 30

respiratory bronchioles and alveoli

Question 31

Absence of which substance leads to respiratory distress syndrome

Answer 31

surfactant

Question 32

Which two substances can be given to increase production of surfactant

Answer 32

thyroxine and cortisol

Question 33

The diaphragm develops during which weeks

Answer 33

5-6th week

Question 34

The central tendon of the diaphragm comes form which embryological structure

Answer 34

septum transversum

Question 35

The tendinous portion of the diaphragm comes form which embryological structure

Answer 35

Paired pleuroperitoneal membranes (somatic mesoderm)-

Question 36

The crura of the diaphragm comes form which embryological structure

Answer 36

Dorsal mesentery of the esophagus

Question 37

Myoblasts originating from somites at which cervical segments form the muscular components of the diaphragm

Answer 37

C3-C5

Question 38

What causes Congenital diaphragmatic hernia

Answer 38

Failure of one /both pleuroperitoneal membranes to close the pericardioperitoneal canal Herniation of abdominal contents into the thorax

Question 39

Congentital diaphragmatic hernia are usually on which side of the body

Answer 39

left side

Question 40

What causes esophageal hiatal hernia

Answer 40

Congential shortness f esophagus which leads to portions of the stomach being in the thorax

Question 41

Pulomonary hypoplasia can be caused by which two conditions

Answer 41

Congenital diaphragmatic hernia Bilateral renal agenesis