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.
Ratio is defined as the way of comparing or showing the relationship between two numbers of the same kind. Ratio is normally expressed by separating the two numbers with a colon(:). Also division sign(/) is used to express ratios. For a ratio to have meaning, both numbers must be nonzero. Some ratios are expressed as fractions or decimals, and some as percentages. The Ratio Formula for two variables 'a' and 'b' is given as,