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Bronchoconstriction is defined as the narrowing of the airways in the lungs (bronchi and bronchioles). Air flow in air passages can get restricted in three ways: [3] a spasmodic state of the smooth muscles in bronchi and bronchioles; an inflammation in the middle layers of the bronchi and bronchioles; excessive production of mucus.
The parasympathetic nervous system decreases respiration and heart rate and increases digestion. Stimulation of the parasympathetic nervous system results in: Constriction of pupils; Decreased heart rate and blood pressure; Constriction of bronchial muscles; Stimulation of digestion and gastric emptying; Increased production of saliva and mucus
Bronchospasm or a bronchial spasm is a sudden constriction of the muscles in the walls of the bronchioles. It is caused by the release (degranulation) of substances from mast cells or basophils under the influence of anaphylatoxins. It causes difficulty in breathing which ranges from mild to severe.
Airway muscular vasculature controls the flow of nutrients to the airways, the temperature of the airways, as well as the clearance of insoluble particles in the airways, which may play an important role in the activity of inhaled bronchodilators, thus affecting airway reactivity and airway tone changes in obstructive lung diseases.
This rate can be altered, however, by nerves that work to either increase heart rate (sympathetic nerves) or decrease it (parasympathetic nerves), as the body's oxygen demands change. Ultimately, muscle contraction revolves around a charged atom (ion) , calcium (Ca 2+ ) , [ 3 ] which is responsible for converting the electrical energy of the ...
Bronchial hyperresponsiveness (or other combinations with airway or hyperreactivity, BH used as a general abbreviation) [1] is a state characterised by easily triggered bronchospasm (contraction of the bronchioles or small airways). Bronchial hyperresponsiveness can be assessed with a bronchial challenge test.
The M 2 muscarinic receptors are located in the heart and lungs. In the heart, they act to slow the heart rate down below the normal baseline sinus rhythm, by slowing the speed of depolarization. In humans, under resting conditions, vagal activity dominates over sympathetic activity.
The Hering–Breuer inflation reflex, named for Josef Breuer and Ewald Hering, [1] [2] [3] is a reflex triggered to prevent the over-inflation of the lung. Pulmonary stretch receptors present on the wall of bronchi and bronchioles of the airways respond to excessive stretching of the lung during large inspirations.