You can trade the five dots that indicate your iPhone's signal strength for a number. No jailbreak required. If you are a numbers person, you may like this iPhone hack that replaces the five dots in the upper-left corner of your iPhone that indicate the strength of your cellular signal with a numerical value. It does not require you to jailbreak your phone -- all you need to do is jump in and out of the hidden Field Test mode.
The subglottis or subglottic region is the lower portion of the larynx, extending from just beneath the vocal cords down to the top of the trachea. The structures in the subglottis are implicated in the regulation of the temperature of the breath.
The superior vena cava (SVC) is the superior of the two venae cavae, the great venous trunks that return deoxygenated blood from the systemic circulation to the right atrium of the heart. It is a large-diameter (24 mm), yet short, vein that receives venous return from the upper half of the body, above the diaphragm. (Venous return from the lower half, below the diaphragm, flows through the inferior vena cava.) The SVC is located in the anterior right superior mediastinum. It is the typical site of central venous access (CVA) via a central venous catheter or a peripherally inserted central catheter.