The trachea bifurcates, or divides, into two branches at its most distal portion and forms the bronchi. The bifurcation is reinforced by a cartilaginous plate called the carina. Like the trachea, each bronchus is made up of cartilaginous rings to keep the lumen open as it goes into the lung. As the branches get smaller, they are called secondary bronchi and segmental (or tertiary) bronchi.
Pins and Needles - Paraesthesia. The most common cause of pins and needles is a moderately pinched nerve. Pins and needles is referred to as paraesthesia in the medical community. Did you know that feeling pins and needles can actually be a worse sign than having pain in your arm or leg.
Burning symptoms fall into two main categories: paresthesias and tissue-damage burning symptoms. The two categories are easily distinguished by their very different causes. Temporary paresthesia is a prickling or pins-and-needles sensation that may be perceived as a burning symptom. It is most familiar as the sensation you feel when your leg or arm has fallen asleep because of persistent pressure on a nerve after staying in one position for too long.