CH 1 Fetal Lung Development

List the 5 stages of fetal lung development and the gestational age at which they occur.

1. Embryonal Phase - day 26 to day 52.

2. Pseudoglandular - day 52 to week 16.

3. Canalicular - week 17 to week 26.

4. Saccular - week 26 to week 36.

5. Alveolar - week 36 to term.

Explain the key steps of each stage of fetal development.

1. Embryonal Phase - Development of trachea and major bronchi.

2. Pseudoglandular - Development of remaining conducting airways.

3. Canalicular - development of vascular bed and framework of respiratory acini.

4. Saccular - increased complexity of saccules.

5. Alveolar - development of alveoli.

Identify the gestational age during which extrauterine viability occurs, and explain why it cannot occur earlier.

24 weeks. Before that isn't possible because the capillary system is not sufficient to support gas exchange.

Identify several conditions that lead to abnormal lung development and injury.

What is the role of the type II pneumocyte in surfactant production?

What are the various physiological functions of surfactant?

How does fetal lung liquid differ from amniotic fluid and how is it cleared during and after labor?

Where does the initial lung bud emerge?

The pharynx.

At which stage of lung development is the bronchial tree formed?

The embryonal stage.

What are the minimal developmental features required for an immature human fetus to survive outside of the uterus?

Describe fetal lung liquid.

What do experts say about alveoli at birth?

Which is the lung development stage formerly thought to be the last stage before birth, and characterized by relatively smooth-walled, cylindrical structures subdivided by ridges known as secondary crests?

What represents Reid's laws of human lung development?