Wall bronchial

Bronchiectasis Chronic dilation of bronchi or bronchioles as a result of inflammatory disease or obstruction associated with heavy sputum or a chronic condition of one or more bronchi or bronchioles marked by irreversible dilatation and destruction of the bronchial walls. 

Smooth muscle Bronchial Gastrointestinal wall Sphincter Contraction Contraction Relaxation Bronchoconstriction Vomiting, cramps, diarrhea Fecal incontinence... 

Bronchial smooth muscle tone. Changes in bronchial smooth muscle tone are particularly important in the bronchioles compared to the bronchi. Recall that the walls of the bronchioles consist almost entirely of smooth muscle. Contraction and relaxation of this muscle has a marked effect on the internal radius of the airway. An increase in bronchial smooth muscle tone, or bron-choconstriction, narrows the lumen of the airway and increases resistance to... 

Continued progression of this pathology can result in residual scarring of small bronchi, augmenting airway obstruction and the weakening of bronchial walls. 

Radiographic findings are nonspecific and include bronchial wall thickening and perihilar and diffuse interstitial infiltrates. 

The respiratory system is divided into two areas the upper and the lower respiratory system. The upper respiratory system is composed of the nose, sinuses, mouth, pharynx (section between the mouth and esophagus), larynx (the voice box), and the trachea or windpipe. The lower respiratory system is composed of the lungs and its smaller structures, including the bronchi and the alveoli. The bronchial tubes carry fresh air from the trachea through a series of branching tubes to the alveoli. The alveoli are small blind air sacs where the gas exchange with the blood occurs. An estimated 300 million alveoli are found in a normal lung. These alveoli contribute a total surface area of approximately 70 m2. Small capillaries found in the walls of the alveoli transport the blood an estimated 100 ml of blood is in the capillaries at any moment. 

Two different circulatory systems, the bronchial and the pulmonary, supply the lungs with blood [133], The bronchial circulation is a part of the systemic circulation and is under high pressure. It receives about 1% of the cardiac output and supplies the conducting airways, pulmonary blood vessels and lymph nodes [133], It is important for the distribution of systemically administered drugs to the airways and to the absorption of inhaled drugs from the airways [18]. The pulmonary circulation comprises an extensive low-pressure vascular bed, which receives the entire cardiac output. It perfuses the alveolar capillaries to secure efficient gas exchange and supplies nutrients to the alveolar walls. Anastomoses between bronchial and pulmonary arterial circulations have been found in the walls of medium-sized bronchi and bronchioles [18, 65, 67],... 

The tracheo-bronchial epithelium forms the interface between the conducting airways and inspired air. As described above, the epithelium is layered upon a connective tissue substratum consisting of a basement membrane, lamina propria, and submucosa [6], The submucosa contains elastic fibres, a muscularis mucosa, connective tissues and seromucous glands. Lymphatics are also located in the bronchial walls [2],... 

Bai A, Eidelman DH, Hogg JC, James AL, Lambert RK, Ludwig MS, Martin J, McDonald DM, Mitzner WA, Okazawa M, Pack RJ, Pare PD, Schellenberg RR, Tiddens HA, Wagner EM, Yager D (1994) Proposed nomenclature for quantifying subdivisions of the bronchial wall. J Appl Physiol 77(2) 1011-1014. 

Mathias NR, Timoszyk J, Stetsko PI, Megill JR, Smith RL, Wall DA (2002) Permeability characteristics of calu-3 human bronchial epithelial cells In vitro-in vivo correlation to predict lung absorption in rats. J Drug Target 10(1) 31—40. 

Eaton EA, Walle UK, Wilson HM, Aberg G, Walle T (1996) Stereoselective sulphate conjugation of salbutamol by human lung and bronchial epithelial cells. Br J Clin Pharmacol 41 (3) 201—206. 

Two membrane-receptive binding sites called and receptors mediate the pharmacological effect of histamine. Hj receptors are located in smooth muscle of vessels, and bronchial and gastrointestinal tract, while H2 receptors are found in the walls of the stomach, myocardium, and certain vessels. 

Significantly increased lung weights were observed in rats exposed 23.6 hours/day to nickel oxide at 0.8 mg nickel/m for 21 days, and at 0.2 mg nickel/rh for 28 days (Weischer et al. 1980). Microscopic examinations of the lungs were not completed in this study. Hyperplasia of the bronchial epithelium was observed in rats exposed intermittently to nickel chloride at 0.11 mg nickel/m for up to 6 weeks (Bingham et al. 1972) and in rats examined 20 months after a 1-month intermittent exposure to nickel oxide at 0.5 mg nickel/m (Horie et al. 1985). Alveolar wall thickening was observed in rats exposed intermittently to 0.12 mg nickel/m as nickel oxide for up to 6 weeks (Bingham et al. 1972). Pneumonia and bronchial epithelial metaplasia were observed in rats exposed intermittently for 1 year to 0.2 mg nickel/m as nickel oxide (Tanaka et al. 1988). 

Three factors contribute to airway obstruction in asthma (1) contraction of the smooth muscle that surrounds the airways (2) excessive secretion of mucus and in some, secretion of thick, tenacious mucus that adheres to the walls of the airways and (3) edema of the respiratory mucosa. Spasm of the bronchial smooth muscle can occur rapidly in response to a provocative stimulus and likewise can be reversed rapidly by drug therapy. In contrast, respiratory mucus accumulation and edema formation are likely to require more time to develop and are only slowly reversible. 

Contraindications Active or latent bronchial asthma, acute inflammatory GI tract conditions, anastomosis, bladder wall instability, cardiacorcoronary artery disease, epilepsy, hypertension, hyperthyroidism, hypotension, mechanical GI or urinary tract obstruction or recent GI resection, parkinsonism, peptic ulcer, pronounced bradycardia, vasomotor instability... 

As indicated previously, bronchospasm is often present in COPD—that is, in chronic bronchitis and emphysema.121 Chronic bronchitis is a clinical diagnosis applied to a long-standing inflammation of the bronchial tree. Emphysema is a pathologic condition marked by the destruction of alveolar walls and enlargement of the terminal air spaces. 

Deposition by diffusion is the main mechanism for particles smaller than 0.5 pm, and is important in bronchioles, alveoli, and bronchial bifurcations. Aerosol particles are displaced by a random collision of gas molecules this results in particle collision with the airway walls [24]. Deposition by diffusion increases with the decrease in particle size, and breath-holding following inhalation was also found to increase this deposition [25]. 

Airflow obstruction in asthma is due to bronchoconstriction resulting from contraction of bronchial smooth muscle, inflammation of the bronchial wall, and increased mucous secretion. Asthmatic attacks may be related to recent exposure to allergens, inhaled irritants leading to bronchial hyperactivity and inflammation of the airway mucosa. The symptoms of asthma may be effectively treated by several drugs, but none of the agents provide a cure for this obstructive lung disease. 

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