Video Transcript
What is the function of ciliated
epithelial cells in the first line of defense? (A) To secrete mucus to trap
pathogens and protect the lungs. (B) To protect the female
reproductive system from infection. (C) To move dust and pathogens away
from the lungs. (D) To secrete lysozyme and destroy
invading bacteria. (E) To secrete hydrochloric acid to
destroy microbes.
This question is asking us about
ciliated epithelial cells in the first line of defense, sometimes known as the
innate immune system. The immune system is a network of
cells and proteins that defend us against infection. It can be divided into innate, or
nonspecific, immunity and adaptive, or specific, immunity.
Innate immunity is rapid and is the
first line of defense our body uses while the adaptive immune response develops. It includes barriers like our skin
that can prevent pathogens from entering our body and causing infection. Innate immunity is nonspecific,
meaning it fights all pathogens the same way. While skin does a good job of
protecting our body from the outside, mucous membranes act to protect our body
cavities and internal surfaces.
Here’s what a typical mucous
membrane looks like. The cell in the center is a goblet
cell and is the one that secretes mucus. The cells on either side are
ciliated epithelial cells. You can see the cilia on top of the
cells. Cilia are hairlike structures that
extend from the surface of these cells and can work to trap foreign particles and
move them away.
Mucous membranes can be found all
over the body, including the eyes, ears, nose, mouth, lungs, and many more. In the lungs, dust and foreign
particles can be swept away by ciliated epithelial cells. This helps to protect the lungs
from these materials.
Therefore, the option that best
describes the function of ciliated epithelial cells in the first line of defense is
given by answer choice (C): to move dust and pathogens away from the lungs.
