respiratory system – дыхательный аппарат oxygen – кислород carbon – углерод dioxide – диоксид nasal cavity – носовая впадина pharynx – зев larynx – гортань trachea – трахея bronchi – бронхи bronchioles – бронхиолы nasal septum – носовая перегородка nostril – ноздря vestibule – вестибулярный respiratory area – дыхательная область olfactory area – обонятельная область paranasal sinuses – параназальные пазухи
35. Nasopharynx and larynx
Nasopharynx is the first part of the pharynx. It is lined by a pseudostratified, ciliated, columnar. Epithelium with goblet cells: under the epithelium, a gland-containing connective tissue layer rests directly on the periosteum of the bone. The cilia beat towards the oropharynx, which is composed of a stratified, squamous, nonkeratinized epithelium. The pharyngeal tonsil, an aggregate of nodular and diffuse lymphatic tissue, is located on the posterior wall of the nasopharynx subjacent to the epithelium. Hypertrophy of this tissue as a result of chronic inflammation results in a condition known as adenoiditis. Larynx is a passageway that connects the pharynx to the trachea and contains the voicebox. Its walls are composed of cartilage held together by fibroelastic connective tissue. The mucous layer of the larynx forms two pairs of elastic tissue folds that extend into the lumen. The upper pair are called the vestibular folds (or false vocal cords), and the lower pair con stitute the true vocal cords. The epithelium of the ventral side of the epiglottis and of the vocal cords is composed of stratified, squamous, nonkeratinized cells. The remainder of the larynx is lined with ciliated, pseudostratified, columnar epithelium. All cilia, from the larynx to the lungs, beat upward toward the nasopharynx.
nasopharynx – носоглотка first – сначала pseudostratified – псевдомногослойный ciliated – снабженный ресничками columnar – колоночный epithelium – эпителий goblet cells – кубические клетки gland-containing – содержащий железу connective tissue – соединительная ткань layer – слой directly – непосредственно periosteum – надкостница bone – кость cilia – ресница oropharynx – верхняя часть глотки stratified – стратифицированный squamous – чешуйчатый nonkeratinized – некеритизированный somewhere – где-нибудь, куда-нибудь, где-то, куда-то
The trachea, a hollow cylinder supported by 16–20 cartilaginous rings, is continuous with the larynx above and the branching primary bronchi below. Mucosa of the trachea consists of the typical respiratory epithelium, an unusually thick basement membrane, and an underlying lamina propria that is rich in elastin. The lamina propria contains loose elastic tissue with blood vessels, lymphatics, and defensive cells. The outer edge of the lamina propria is defined by a dense network of elastic fibers. Submucosa consists of dense elastic connective tissue with seroriltfcous glands whose ducts open onto the surface of the epithelium. Cartilage rings are C-shaped hyaline cartilage pieces whose free extremities point dorsally (posteriorly). They are covered by a perichondrium of fibrous connective tissue that surrounds each of the cartilages. Smooth muscle bundles (trachealis muscle) and ligaments span the dorsal part of each cartilage. Adventita a consists of peripheral dense connective tissue that binds the trachea to surrounding tissues.
The trachea branches at its distal end into the two primary bronchi. Short extrapulmonary segments of the primary bronchi exist before they enter the lungs at the hilus and then branch further. The histologic structure of the walls of the extrapulmonary segment of the primary bronchi is similar to that of the tracheal wall.
hollow – пустота cylinder – цилиндр supported – поддержанный cartilaginous rings – хрящевые кольца larynx – гортань above – выше branching – переход primary bronchi – первичные бронхи below – ниже mucosa – слизистая оболочка typical – типичный respiratory epithelium – дыхательный эпителий an unusually – нетипитчно thick – толстый basement – основание underlying – основной lamina – тонкая пластинка rich – богатый elastin – эластин loose – свободный vessel – сосуд lymphatics – лимфатический defensive cells – защитные клетки outer – внешний edge – край
37. Respiratory bronchioles
Respiratory bronchioles are areas of transition (hybrids) between the conducting and respiratory portions of the airways. In addition to the typical bronchiolar epithelium of the terminal bronchioles, these passageways contain outpouchings of alveoli, which comprise the respiratory portion of this system. Terminal bronchioles give rise to respiratory bronchioles. Respiratory bronchioles branch to form two to three alveolar ducts, which are long sinuous tubes. Alveolar sacs are spaces formed by two or more conjoined alveoli. They are lined by the simple squamous alveolar epithelium. Alveoli are the terminal, thin-walled sacs of the respiratory tree that are responsible for gas exchange. There are approximately 300 million alveoli per lung, each one 200–300 mm in diameter. Blood-air interface. Oxygen in the alveoli is separated from hemoglobin in the red blood cells of alveolar capillaries by five layers of membrane and cells: the alveolar epithelial cell (apical and basal membranes) and its basal lamina, the basal lamina of the capillary and its endothelial cell (basal and apical membranes), and the erythrocyte membrane. The total thick ness of all these layers can be as thin as 0,5 mm. Alveolar epithelium contains two cell types. Type I cells completely cover the alveolar luminal surface and provide a thin surface for gas exchange. This simple squamous epithelium is so thin (-25 nm) that its details are beyond the resolution of the light microscope. Type II cells are rounded, plump, cuboidal-like cells that sit on the basal lamina of the epithelium and contain membrane-bound granules of phospholipid and protein (lamellar bodies). The contents of these lamellar bodies are secreted onto the alveolar surface to provide a coating of surfactant that reduces alveolar surface tension. Alveolar macrophages (dust cells) are found on the surface of the alveoli. Derived from monocytes that extravasate from alveolar capillaries, alveotar macrophages are part of the mononu – clear phagocyte system. Dust cells, as their name implies, continuously remove particles and other irritants in the alveoli by phagocytosis.