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What is wrapped around each alveolus?
They provide total surface area of about 100 m2. A typical pair of human lungs contain about 700 million alveoli, producing 70m2 of surface area. Each alveolus is wrapped in a fine mesh of capillaries covering about 70% of its area.
Why is there a film of moisture around the alveolus?
The alveolus is covered in a thin film of moisture, therefore, the oxygen and carobn dioxide will diffuse into this layer and keep their respective concentrations high within the thin film. High concentration gradients for these gases will ensure diffusion occurs quickly.
What is the name of mesh that surrounds the alveoli?
In the alveolar walls there are interconnecting air passages between the alveoli known as the pores of Kohn. The alveolar septa that separate the alveoli in the alveolar sac contain some collagen fibers and elastic fibers. The septa also house the enmeshed capillary network that surrounds each alveolus.
What are the 3 types of alveolar cells?
Each alveolus consists of three types of cell populations:
- Type 1 pneumocytes.
- Type 2 pneumocytes.
- Alveolar macrophages.
What is the anatomical difference between Type 1 and Type 2 alveolar cells?
The key difference between type 1 and type 2 pneumocytes is that type 1 pneumocytes are thin and flattened alveolar cells that are responsible for the gas exchange between alveoli and capillaries, while type 2 pneumocytes are cuboidal alveolar cells that are responsible for the secretion of pulmonary surfactants that …
What is a Type 1 cell?
The type I cell is a complex branched cell with multiple cytoplasmic plates that are greatly attenuated and relatively devoid of organelles; these plates represent the gas exchange surface in the alveolus.
What type of cells are Type 1 alveolar cells?
Type I alveolar cells are squamous extremely thin cells involved in the process of gas exchange between the alveoli and blood. Type II alveolar cells are involved in the secretion of surfactant proteins.