Respiratory bronchiole proceed into:
Correct Answer: Alveolar duct
Description: Bronchioles have a diameter smaller than 1 mm and lack cartilage and glands within their walls. Goblet cells (and cilia) decrease in number and almost negligible at the levels of bronchioles (small lumen). Hyaline cartilage also is almost non-existent at the levels of bronchioles. Epithelium gradually changes from pseudostratified columnar to simple columnar to cuboidal to squamous.
Alveolus is lined by type-I pneumocyte (simple squamous epithelium) for respiratory gas exchange. Type- II pneumocyte is a cuboidal cell for surfactant secretion.
Bronchial arteries (branches of descending thoracic aorta) supply till the level of respiratory bronchiole. They perfuse the proximal air conducting pathways including tertiary and terminal bronchioles and reach till the beginning of respiratory unit. Pulmonary arteries alone vascularize the further distal pathways, including alveolar ducts and the alveoli.
Category:
Anatomy
Get More
Subject Mock Tests
Practice with over 200,000 questions from various medical subjects and improve your knowledge.
Attempt a mock test nowMock Exam
Take an exam with 100 random questions selected from all subjects to test your knowledge.
Coming SoonGet More
Subject Mock Tests
Try practicing mock tests with over 200,000 questions from various medical subjects.
Attempt a mock test now