What is the name of the tiny air sacs in the lungs where gas exchange/ external respiration takes place?

The alveoli are tiny air sacs in the lungs where gas exchange takes place.

When we breathe in, which of the following occurs to bring air into the lungs?

Which part of the respiratory system pushes and pulls the lungs to draw air in and out?

What type of tissue would be located between the blood and the air in the lungs to allow for gas exchange?Multiple ChoiceSimple squamous epitheliumSimple cuboidal epitheliumStratified squamous epitheliumSimple columnar epithelium

The human gas-exchanging organ, the lung, is located in the thorax, where its delicate tissues are protected by the bony and muscular thoracic cage. The lung provides the tissues of the human body with a continuous flow of oxygen and clears the blood of the gaseous waste product, carbon dioxide. Atmospheric air is pumped in and out regularly through a system of pipes, called conducting airways, which join the gas-exchange region with the outside of the body. The airways can be divided into upper and lower airway systems. The transition between the two systems is located where the pathways of the respiratory and digestive systems cross, just at the top of the larynx.T