Department of Histology and Embryology, P. J. Šafárik University, Medical

Faculty, Košice

Respiratory system, development and microscopic structure: Sylabus for foreign

students

Author: prof. MUDr. Eva Mechírová, CSc.

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Development of respiratory system – 4th

week

Development of the lungs

1. The pseudoglandular period (4 -17 week) - bronchi

2. The canalicular period (16-25 week) - bronchiols

3. The early alveolar period (24 week to birth) - alveoli

4. The late alveolar period (up to 8 years ) – alveoli

Microscopic structure of the respiratory system

From the functional point of view the respiratory system comprises :

conducting portion – nasal cavity

– paranasal sinuses

– nasopharynx – larynx – trachea – bronchi – bronchioles – terminal bronchioles respiratory portion

- respiratory bronchioles - alveolar ducts - alveolar sacs - alveoli

Nasal cavity