Development of the Respiratory System

Question 1

Respiratory diverticulum (lung bud) appears as outgrowth of _______

Answer 1

foregut

Question 2

Inner lining of larynx, trachea, bronchi, & lungs originate from what germ layer?

Answer 2

Endoderm origin

Question 3

Cartilaginous, muscular, & connective tissue components of trachea & lungs are from what germ layer?

Answer 3

Splanchnic mesoderm

Question 4

T/F Initially the Lung bud (Resp. Diverticulum) has open communication with the foregut.

Answer 4

True

Question 5

As the bud grows ______, _______ ridges begin to separate the lung bud from the ____

Answer 5

caudally
tracheoesophageal ridges
lung bud from the foregut

Question 6

Why are the tracheoesophageal ridges so important?

Answer 6

These ridges are important in creating the septis to separate the Gi tract from the resp tract.

Question 7

The Tracheoesophageal Ridges will fuse to form the _______________.

Answer 7

tracheoesophageal septum

Question 8

The Dorsal aspect of the tracheosophageal septum leads to –>
Ventral –>

Answer 8

DEV-T
Dorsal-Esophagus
Ventral - Trachea

Question 9

Through what does the respiratory diverticulum maintain communication with the pharynx?

Answer 9

laryngeal orifice

Question 10

Abnormalities in partitioning of esophagus & trachea by tracheoesophageal septum result in_______ with or without _____________.

Answer 10

esophageal atresia  
tracheoesophageal fistulas (TEFs)

Atresia: blind outpocketing
Fistulas : abnormal connection with esophagus & trachea.

Question 11

Most frequent abnormality is shown which occurs with the upper esophagus ending in a _____ and the lower segment forming a __________________.

Answer 11

blind pouch

fistula with the trachea

Question 12

Laryngeal cartilages and musculature arise from pharyngeal arch pairs ______

Answer 12

4 and 6

Question 13

Mesenchyme of the 4th & 6th arch transform into:

Answer 13

CAT

Cricoid cartilage
Arytenoid cartilage
Thyroid cartilage

Question 14

Epiglottis forms from mesenchyme of the caudal ________________

Answer 14

hypopharyngeal eminence

Question 15

Which germ layer does epiglottis form from?

Answer 15

mesenchyme of the caudal hypopharyngeal eminence

Question 16

Lining of larynx is from the _____.

Answer 16

endoderm

Question 17

All cartilages are _________.

Answer 17

splenchnic mesoderm

Question 18

Laryngeal cartilages are associated with arch

Answer 18

4 & 6 pharguneal arches. (CN 10)

Question 19

Laryngeal epithelium is proliferating rapidly during this time, resulting in ___________.

Answer 19

temporary occlusion of lumen

Question 20

vacuolization & recanalization produces ______ & _______, which are bounded by the __________________

Answer 20

lateral recesses
laryngeal ventricles
false & true vocal cords

Question 21

Laryngeal mm. arising from 4th arch are innervated by _________

Answer 21

superior laryngeal n.

Question 22

Laryngeal mm. arising from 6th arch are innervated by _________

Answer 22

recurrent laryngeal n.

Question 23

When the resp. Diverticulum grows caudally from larynx it ends up forming what?

Answer 23

trachea

Question 24

At what level does the lung bud bifurcate into R & L primary bronchial buds?

Answer 24

T4

Question 25

Lung bud splits/bifurcates and forms _______. It then continues to grow caudally and ____ and form the ___________.

Answer 25

R & L primary bronchial buds
laterally
secondary bronchial buds.

Question 26

How many secondary bronchial buds does the R bronchial bud form?

How many secondary bronchial buds does the L bronchial bud form?

Answer 26

3 secondary bronchial buds

2 secondary bronchial buds

Question 27

How many tertiary bronchial buds does the R/L side of the secondary bronchial bud(s) form?

Answer 27

R: 10
L: 8

Question 28

As the lung buds grow in both the caudal & lateral directions, they expand into the _________

Answer 28

pericardioperitoneal canals

Question 29

What narrows and eventually forms the pleural cavaties?

Answer 29

pericardioperitoneal canals

Question 30

___________ gives rise to visceral pleura of the lungs

Answer 30

Splanchnic mesoderm

Question 31

Splanchnic mesoderm gives rise to ______ of the lungs

Answer 31

visceral pleura

Question 32

_________ lining thoracic body wall gives rise to the parietal pleura

Answer 32

Somatic mesoderm

Question 33

Somatic mesoderm lining thoracic body wall gives rise to the _________

Answer 33

parietal pleura