What does ciliate action in the trachea accomplish?

Question

additional question: why do the centers of the mature red blood corpuscles appear light in color?

Answer 1

The cilia help move mucus and trapped contaminants up the trachea to the point at which they can be swallowed.  Gross, I know, but the stomach is the ideal place to dispose of potential invaders, and break down and "recycle" the components of the mucus.  Without functioning cilia, the mucus would build up in the lungs, preventing oxygen absorption and increasing the risk of infection (people with cystic fibrosis have malfunctioning cilia).

The red blood cells are biconcave.  When they mature, the inside of the cell is filled with hemoglobin, the nucleus and DNA are broken down, and the cytoskeleton pulls two ends of the cell together to produce the dent.  This shape allows the red blood cell to be flexible (so it can fit through capillaries) and it increases the surface area (to allow better O2 transfer).  Sickle Cell Anemia is a condition where the red blood cells don't take the right shape - instead, they have a banana-like shape.  This interferes with O2 storage and transfer, and also causes painful and dangerous clogs in the capillaries, since their shape causes them to get jammed together.

Answer 2

The upward sweep brings up mucus, which has been trapping dust, bacteria, etc. so it doesn't wind up in your lungs.  Looggie, anyone?

When mature the RBCs no longer have a nucleus.  Also they are especially thin in that area.