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.
Best Answer: The trachea is the part of the human respiratory system that conducts the path of air from the external nasal cavity (nostrils) to the lungs.It is lined by 'C'- shaped cartilaginous rings that prevent it from collapsing.Before entering into the lungs, the trachea further divides into Bronchi and Bronchioles which eventually lead to the Alveoli where the exchange of gasses takes place. Hope this helped :) - Saad Mustafa.eport Abuse. The trachea is more commonly known as the windpipe. It is the airway through which respiratory air passes in organisms. The trachea, commonly known as the windpipe, is a tube about 4 inches long and less than an inch in diameter in most people.