Author Question: What is the major source of respiratory tract secretions in the normal lung? a. Bronchial glands ... (Read 97 times)

Jkov05 · **on:** Jul 16, 2018

What is the major source of respiratory tract secretions in the normal lung?

a. Bronchial glands
b. Clara cells
c. Goblet cells
d. Mast cells

Question 2

What can the release of histamine and other chemical mediators from the mast cells in the air-ways cause? 1. Bronchoconstriction 2. Bronchodilation 3. Vasoconstriction 4. Vasodilation

a. 2 and 4 only
b. 1 and 3 only
c. 2 and 3 only
d. 1 and 4 only

zogaridan · **Reply #1 on:** Jul 16, 2018

Answer to Question 1

ANS: A
Normally, the respiratory tract produces approximately 100 ml of mucus per day. Most of the mucus formed in the larger airways is produced by the bronchial glands.

Answer to Question 2

ANS: D
Mast cells are also found in the submucosa and release numerous and potent vasoactive and bronchoactive substances such as histamine. Histamine causes vasodilation and bronchocon-striction, acting directly on smooth muscle.