Why are antihistamines used to treat allergic rhinitis and allergic asthma? What symptoms of each disease, respectively, do they alleviate
What will be an ideal response?
Mast cells activated by inhaled allergens in the type I hypersensitivity reaction that causes allergic rhinitis or asthma release histamine. Histamine binding to its receptors on smooth muscle causes the bronchial constriction typical of asthma and the difficulty in breathing. Histamine binding to receptors on vascular endothelium causes increased permeability of the epithelium and inflammation of nearby tissue, causing the runny nose and swollen eyes typical of allergic rhinitis, and also an accumulation of mucus and fluid in the bronchi typical of allergic asthma. By blocking histamine action, antihistamines help alleviate these symptoms.
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Which one of the following statements is true regarding the stages of development?
A. The pre-embryonic stage involves the formation of a blastocyst. B. The embryonic stage occurs after the 8th week of development. C. Myelination occurs during the fetal stage of development. D. Both A and C E. All of the above
Which medication is a potassium-sparing diuretic?
A) Aldactone B) Lasix C) Ditropan XL D) Diamox
If the ST segment is depressed below baseline it could mean which of the following?
a. Myocardial ischemia b. Digoxin overdose c. Electrolyte imbalance d. Only A and B e. All the above
The majority of fat in the body consists of
A) cholesterol. B) lipids. C) polysaccharides. D) triglycerides.