Development of respiratory system

Question 1

When does the Respiratory diverticulum/lung bud appear?

Answer 1

4 Weeks

Question 2

What part of the primitive gut does the lung bud develop from?

Answer 2

Foregut

Question 3

Endoderm forms…

Answer 3

Epithelial lining of larynx, trachea, bronchi and lung

Question 4

Visceral mesoderm forms…

Answer 4

Cartilage, muscular, connective tissue of lungs

Question 5

Connection where one should not be=

Answer 5

fistula

Question 6

Blocking of something that normally occurs=

Answer 6

atresia

Question 7

Most common developmental anomalies of the respiratory system=

Answer 7

Esophageal atresia (distal esophagus)

Question 8

H-Type fistula

Answer 8

Communication of esophagus with trachea with both proximal and distal

Question 9

Extremely rare forms of fistula

Answer 9

Proximal esophageal fistula or both proximal and distal fistula separately

Question 10

Growth of bronchi

Answer 10

Lung bud- 2 bronchial buds- R & L main/primary bronchi
R=3 secondary lobes-10 tertiary lobes
L=2 secondary lobes- 8 tertiary lobes

Question 11

During branching of lung bud, regulation and communication involves…

Answer 11

FGF (fibroblast growth factor)

Question 12

How long does it take for branching to be complete?

Answer 12

20 weeks/5 months

Question 13

What vertebral level does the trachea bifurcate?

Answer 13

T4

Question 14

When is the canalicular phase? And what is the significance of this phase?

Answer 14

Until end of 7th month
Alveolar sacs presents so premature infant may survive

Question 15

When is the terminal sac phase? And what happens in this phase?

Answer 15

8th month-10 years of life
Number of terminal sacs increase

Question 16

When is the terminal sac phase? And what happens in this phase?

Answer 16

8th month-10 years of life
Number of terminal sacs increase
Increase P1 P2 and BAB formed

Question 17

Before birth, lungs contain…

Answer 17

Chloride rich fluid, protein, mucus, surfactant

Question 18

Fetal breathing doesn’t happen until emerging from birth canal. T or F

Answer 18

False. Breathing movements begin just before birth, conditioning respiratory muscles.

Question 19

Changes in respiration during birth- after birth.

Answer 19

During birth= fluid rapidly resorbed by blood capillaries, surfactant remains and increases
After birth= alveoli size increases, O2 from placenta stops, bronchial tree grows

Question 20

How much of adult alveoli are present at birth?

Answer 20

1/6 remaining are fromed in first 10 years of life