The CpG PAMP is recognized by the pattern recognition receptor (PRR) Toll-Like Receptor 9 (TLR9), which is constitutively expressed only in B cells and plasmacytoid dendritic cells (pDCs) in humans and other higher primates.
The trachea is an important structure within your respiratory system, which is the organ system that delivers oxygen to your bloodstream. The trachea is a rigid tube that conducts air from your larynx to your bronchi. The trachea's rigidity is maintained by a series of cartilaginous rings arranged along its length called C-shaped cartilage rings.
A: The trachea is the tube in the throat that connects the mouth and nose to the lungs. It is also called a windpipe, and its function is to transport the air a person breathes in through his nose or mouth into the lungs. Without the trachea, the lungs do not receive oxygen, and humans cannot survive.