First Breath

Question 1

What are the stages of lung development?

Answer 1

Embryonic 0-5 weeks
Pseudoglandular 5-17 weeks
Cannalicular 16-25 weeks
Alveolar 25 weeks-term

Question 2

Where do the lungs develop from?

Answer 2

Foregut derivative
- Anterior outpouching

Question 3

When is the respiratory diverticulum developed?

Answer 3

By the 5th week the lung buds enlarge to form right and left main bronchi

Question 4

What happens in the pseudoglandular phase?

Answer 4

5-17 weeks
Exocrine gland only
Major structural units formed.
Angiogenesis
Mucous Glands
Cartilage
Smooth Muscle
Cilia
Lung fluid

Question 5

What happens in the Canalicular phase?

Answer 5

16-25 weeks.
Distal Architecture
Vascularisation i.e formation of capillary bed
Respiratory bronchioles.
Alveolar ducts.
 Terminal sacs

Question 6

What happens in the Alveolarisation phase?

Answer 6

25 weeks to birth
Alveolar sacs
Type 1 and Type 2 cells
Alveoli simple with thick interstitium

Birth to 3-5 years?
Thinning of alveolar membrane and interstitium
↑ complexity of alveoli

Question 7

What happens during the stages of lung development?

Answer 7

Major airways defined
Nests of angiogenesis
Smaller airways down to respiratory bronchioles

Terminal bronchioles
Capillary Beds
Alveolar ducts

Alveolar budding, thinning and complexification

Question 8

What can go wrong during the embryonic phase?

Answer 8

Laryngeal, Tracheal and oesophageal atresia,tracheal and bronchial stenosis,pulmonary agenesis

Question 9

What can go wrong during the pseudoglandular phase?

Answer 9

Bronchopulmonary sequestration,cystic adenomatoid malformations, alveolar-capillary dysplasia,

Question 10

What can go wrong during the alveolar phase?

Answer 10

Acinar Dysplasia,
alveolar capillary dysplasia,
Pulmonary hyoplasia

Question 11

What is oxygen in systemic blood vessels?

Answer 11

Vasoconstrictor

Question 12

What is oxygen in pulmonary blood vessels?

Answer 12

Vasodilator

Question 13

What is the purpose of lung fluid?

Answer 13

Fetal airways are distended with fluid
Fluid aids in lung development
Actively secreted by lungs

Question 14

What happens during the first breath?

Answer 14

Fluid squeezed out of lungs by birth process
Adrenaline stress leading to increased surfactant release.
Air inhaled
Oxygen vasodilates pulmonary arteries
Umbilical arteries constrict
Ductus arteriosus constricts

Question 15

What is the foramen ovale?

Answer 15

Passage between the two atria which is responsible for bypassing the majority of the circulation

Question 16

What is the ductus arteriosus?

Answer 16

Pulmonary trunk linked to the distal arch of the aorta by the ductus arteriosus, permitting blood to bypass pulmonary circulation

Muscular wall contracts to close after birth (a process mediated by bradykinin)

Question 17

What is the ductus venosus?

Answer 17

Oxygenated blood entering the foetus also needs to bypass the primitive liver. This is achieved by passage through the ductus venosus, which is estimated to shunt around 30% of umbilical blood directly to the inferior vena cava

Question 18

What is pulmonary