Alveolar Microanatomy

The bronchiole branches into the _________ bronchiole.

terminal

The terminal bronchiole branches into the __________ bronchiole,

respiratory

The respiratory bronchioles become _______ _____.

alveolar ducts

The alveolar ducts then become ______ ____.

alveolar sacs

The alveolar sacs become individual _____.

alveoli

Each alveolus has its own _______ bed, ensuring gas exchange is efficient and rapid.

capillary

What are the different cells found in the alveolus?

1) Simple squamous cell 2) Cuboidal cells 3) Alveolar Macrophage (Dust Cell)

The simple squamous cells of the alveolus are called ______ __ cells; form the majority of the surface area of the alveolus

Type I

The cuboidal cells of the alveolus are called ______ __

cells; they make up a smaller percentage of the surface but are more numerous

Type II

Type II cells of the alveolus secrete _________ which decreases surface tension of thin layer of water in the alveolus.

surfactant

Surfactant makes sure that when air leaves the alveolus, that it doesn’t _______ on itself and the edges do not _____ together.

collapse, stick

Alveolar Macrophages (dust cells) phagocytize _____ or ________ that may make their way into the alveoli.

debris, invaders

Type I (Simple Squamous Cells) and blood cells are in such close contact that they share a basement membrane called a ___________ membrane.

respiratory

The respiratory membrane is a thin barrier to enable quick and efficient ____ exchange.

gas

______ fibers are found in the walls of each alveolus allow the alveoli to keep their round shape as well as expand and contract.

elastic