What does a ciliated epithelial cell do

Respiratory epithelium

Synonyms: respiratory ciliated epithelium, airway epithelium
English: ciliated respiratory epithelium, respiratory epithelium

1 definition

The respiratory epithelium is a layer of specialized epithelial cells that lines most of the airways. It is characterized by cilia (cilia) on the cell surface facing the lumen (apical cell pole).

2 histology

The respiratory epithelium is a multi-row high prismatic epithelium that is equipped with kinocilia and goblet cells. Physiologically, the goblet cells within the epithelium make up between 15-20% of the epithelium. All cells are connected to the relatively pronounced basal lamina.

The thickness of the ciliated epithelium continuously decreases along the bronchial tree in the direction of the alveoli. The terminal bronchioles show only a single layer of ciliated epithelium.

2.1 Kinocilia-bearing cells

They make up the main part of the cells of the ciliated epithelium. Their kinocilia at the apical cell pole are mobile protuberances of the cell membrane that are about 7-10 µm long and about 0.3 µm in diameter. Their motility is ensured by so-called microtubules.

2.2 goblet cells

The goblet cells are unicellular, cup-shaped, intraepithelial glands that - in addition to the serous and mucosal glands of the lamina propria - produce bronchial mucus. The mucins secreted by them cover the epithelium and moisten the air that passes by.

2.3 Club cells

The club cells, formerly Clara cells, are secretory cells in the distal part of the airways. They are found in the bronchioli and in the ductus alveolares. They produce a glycoprotein-containing secretion.

2.4 Other cells

In addition to these two types of cells, the ciliated epithelium also has Sensory cellsthat have contact with afferent nerve fibers at their basal pole. When irritated, they trigger the coughing or sneezing reflex. The Basal cells represent a preliminary stage of the mature epithelial cells and ensure the cell replenishment.

3 physiology

Ciliated epithelium has a sophisticated self-cleaning mechanism called mucociliary clearance (MCC). The moving kinozilen line the airways like a thick lawn. Their coordinated movement is directed towards the throat. As a result, the bronchial mucus and smaller foreign bodies and microorganisms that have penetrated the airways are constantly transported out of the airways.

The respiratory epithelium does not serve - even if the name suggests it - for gas exchange.

4 occurrences

Respiratory epithelium is found in the following locations: