Quadriplegia

Paralysis of all four limbs.

Quadrant

One fourth of a circle; in anatomy. regions are often arbitrarily divided into quadrants; ie abdominal region.

Pylorus

Muscular part of the stomach,  adjacent to its opening into the duodenum.

Pyloric Sphincter

Circular muscle that regulates the passage of contents from the stomach into the duodenum.

Pyloric Canal

Canal in the muscular part of the stomach, adjacent to opening into the duodenum.

Pus

Yellowish-white fluid that may accumulate in an inflamed area; made up of dead tissue, white blood cells, and their remains and other proteins.

Pulse

Pressure wave felt on palpating the superficial arteries; as it travels, the wave expands the artery walls.

Pulp Cavity

The cavity inside a tooth.