Alveoli and Gas Exchange

What is the main function of the respiratory system?

• to provide oxygen to red blood cells and remove carbon dioxide from the body

• to remove liquid and solid wastes

• to break down food and absorb nutrients

• to deliver oxygen to the cells of the body directly

Given the following structures:

1. alveoli

2. bronchi

3. bronchioles

Which of the following is the correct order in which air would flow during inspiration (inhaling)?

• 1,2,3

• 2,1,3

• 2,3,1

• 3,2,1

The air sacs that are covered with tiny blood vessels where gas exchange takes place...

• bronchi

• pseudostratified columnar epithelium

• capillaries

• alveoli

What gas is: the waste product of cellular respiration, picked up red blood cells when they pass the cells of the body, dropped off in the alveolus, and removed from the body during an exhale?

• carbon dioxide.

• nitrogen.

• oxygen.

As the red blood cells move past the alveoli, they pick up _.

As the red blood cells move past the alveoli, _ diffuses from the red blood cells into the airspace of the alveoli.

During gas exchange, carbon dioxide and oxygen move through the process of _- moving from an area of high concentration to an area of low concentration though the walls of the alveoli and the thin walls of the capillary

The alveoli (type 1 pneumocytes) and walls of the capillary are made out of very thin cells called ___ - they are so thin that they allow for gases to move through them

• simple squamous cell

• goblet cells

• macrophages

• ciliated pseudostratified epithelial cells

Which of the following are features of the alveoli that adapt them to gas exchange?

I. High surface area

II. Thin walls

III. Dry surfaces

• I and II only

• I only

• II and III

• I, II, and III

How are the thin, flat cells of the alveoli well adapted for gas exchange?

• They provide a short diffusion path from the alveoli to capillaries

• They secrete a surfactant that prevents the walls of the alveoli from sticking by breaking surface tension

• They secrete a fluid to allow gases to dissolve and diffuse more efficiently

• They secrete mucus to help trap dirt, particulate matter, and pathogens