Alveolo-Capillary Membrane
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The exchange of respiratory gases takes place through the alveolo-capillary membrane (hemo-respiratory barrier). It is a thin layer (0.6–2 μm) that is part of the pulmonary alveoli. The total size of the alveolo-capillary membrane is 60–160 m2[1].
Layers alveolocapillary membranes[edit | edit source]
In the thinnest places, the membrane consists of the following 6 layers :
- A layer of fluid containing a surfactant on the inner surface of the alveoli
- Alveolar epithelium - bodies of first order pneumocytes
- Basal membrane of the epithelium
- Interstitium between the basement membrane of the epithelium and the endothelium (a very thin tissue space that contains collagen and elastin fibers)
- Basal membrane of the endothelium
- Capillary endothelium
For respiration to be effective, the diffusion path must be as short as possible. Therefore, sites that are functionally important (sites that do not contain second-order pneumocytes, no cell nuclei, interstitial ligament) have a thickness of 0,6 μm[2]. If we also measure the interalveolar septa, the mean thickness is 2 μm.
References[edit | edit source]
- LÜLLMANN-RAUCH, Renate. Histologie. 1. edition. Praha : Grada, 2012. 576 pp. ISBN 978-80-247-3729-4.
- FONTANA, Josef – TRNKA, Jan – MAĎA, Patrik, et al. Multimediální skripta 3.LF [online]. [cit. 2015-12-09]. <http://fblt.cz/>.
- NEČAS, Emanuel – ŠULC, Karel – VOKURKA, Martin, et al. Patologická fyziologie orgánových systémů. Část I. 1. edition. Praha : Karolinum, 2006. 377 pp. ISBN 978-80-246-0615-6.
