_____ seconds is required for oxygen (O2) concentration to ...

[WhattoUnderstand]

_____ seconds is required for oxygen (O2) concentration to equilibrate (equalize) across the alve-olocapillary membrane.
 
  Fill in the blank(s) with the appropriate word(s).

Question 2

Which structures may be found in the walls of the respiratory bronchi? (select all that apply)
 
  a. Smooth muscle
  b. Surfactant-producing glands
  c. Goblet cells
  d. Ciliated cells
  e. Epithelial lining

[6ana001]

Answer to Question 1

ANS: 0.25

Answer to Question 2

ANS: A, C, D, E
The bronchial walls have three layers: an epithelial lining, a smooth muscle layer, and a connec-tive tissue layer. The epithelial lining of the bronchi contains single-celled exocrine glandsthe mucus-secreting goblet cellsand ciliated cells. Surfactant-producing glands are found in the alveoli.