Question

Where are H1 receptors mainly located in the body?

Options

• Gastric mucosa and blood vessels

• Heart and skeletal muscle

• Skin, lung tissue, and intestinal mucosa

• Brain and central nervous system

Answer 1

H1 receptors are mainly present in the skin, lung tissue, and intestinal mucosa. This anatomical distribution explains why allergic symptoms commonly involve these tissues, manifesting as skin eruptions and itching, respiratory symptoms like wheezing and difficulty breathing, and gastrointestinal symptoms like colic and diarrhea. The prevalence of H1 receptors in these locations makes them the primary sites of allergic manifestations.