I'm not aware of a circle P having any significance in medicine. It is commonly used as a copyright mark for recording [similar to circle c (C) - copyright, and circle r (R) - registered]. I believe circle p - (P) - is meant to be performance recording copyright or phonograph copyright (or something similar)
Also, (P)i is the symbol for a phosphate group in cellular respiration. The phosphate group is added to ADP to create ATP.
The formula is ADP+ (P)i -> ATP+ H2O
Copyright.
On an electrical schematic, the symbol for a motor is a circle with the letter M inside of it. On an electrical schematic, the symbol for a motor is a circle with the letter M inside of it.
A c with a circle around it is the 'copyright' symbol.
It means positive or affirmative in medical abbreviations.
@ - a little letter 'a' in a circle
It's the symbol for anarchy.
It is a big circle with a circle around it
It is the electrical symbol for an Ammeter (a device that measures current).
The most common symbol for the sun is a circle with a dot in the center. This symbol represents the sun's radiant energy and life-giving properties. It is a universal symbol found in various cultures and religions around the world.
A star with a circle around it
It is a ♂. It is an arrow with a circle around it.
Symbol for "registered trademark"