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These hairs, called vibrissae, are thicker than body hair and effectively block larger particles from entering the respiratory tract. They also increase the surface area for particle deposition, improving the nose's ability to filter pathogens. [15] The cough reflex expels all irritants within the mucous membrane to the outside. The airways of ...
A pulmonary alveolus (pl. alveoli; from Latin alveolus ' little cavity '), also called an air sac or air space, is one of millions of hollow, distensible cup-shaped cavities in the lungs where pulmonary gas exchange takes place. [1] Oxygen is exchanged for carbon dioxide at the blood–air barrier between the alveolar air and the pulmonary ...
The trachea is an area of dead space: the oxygen-poor air it contains at the end of exhalation is the first air to re-enter the posterior air sacs and lungs. In comparison to the mammalian respiratory tract , the dead space volume in a bird is, on average, 4.5 times greater than it is in mammals of the same size.
Oxygen stoichiometric phases (δ = 0), denoted as Hex0, crystallize in the hexagonal P6 3 cm symmetry which can be described as a layered structure in which layers of R + 3 cations in eight-fold coordination are separated by layers of corner-sharing trigonal Mn + 3 O 5 bipyramids. A very important property, from the viewpoint of TSA, is the ...
By mole fraction (i.e., by quantity of molecules), dry air contains 78.08% nitrogen, 20.95% oxygen, 0.93% argon, 0.04% carbon dioxide, and small amounts of other trace gases (see Composition below for more detail). Air also contains a variable amount of water vapor, on average around 1% at sea level, and 0.4% over the entire atmosphere.
The mucosa-associated lymphoid tissue (MALT), also called mucosa-associated lymphatic tissue, is a diffuse system of small concentrations of lymphoid tissue found in various submucosal membrane sites of the body, such as the gastrointestinal tract, nasopharynx, thyroid, breast, lung, salivary glands, eye, and skin.
It may consist of a single layer of barrel-shaped cells without any intercellular spaces or sometimes several cell layers. The cells of the endodermis typically have their primary cell walls thickened on four sides radial and transverse with suberin, a water-impermeable waxy substance which in young endodermal cells is deposited in distinctive ...
The cells in the respiratory epithelium are of five main types: a) ciliated cells, b) goblet cells, c) brush cells, d) airway basal cells, and e) small granule cells (NDES) [6] Goblet cells become increasingly fewer further down the respiratory tree until they are absent in the terminal bronchioles; club cells take over their role to some extent here. [7]