Lumbar puncture. Lumbar puncture (LP), also known as a spinal tap, is a medical procedure in which a needle is inserted into the spinal canal, most commonly to collect cerebrospinal fluid (CSF) for diagnostic testing. The main reason for a lumbar puncture is to help diagnose diseases of the central nervous system, including the brain and spine.
2. ratio-the relation between things (or parts of things) with respect to their comparative quantity, magnitude, or degree; an inordinate proportion of the book is given over to quotations; a dry martini has a large proportion of gin. proportion.
A ratio is a comparison between two numbers and it is described as a fraction. If x and y are any two numbers, then the ratio of x to y is $\frac{x}{y}$ , $(y \neq 0)$.ow to Calculate Ratio. Example: The ratio of girl to boy in a class is 12:16. To simplify the ratio we can make the numbers into smaller ratios so as to compare easily. This can be done by dividing the ratio by same number on each side.