For this telescope, the lenses are a concave convex (one side curved out and the other curved in) and a plano concave (one flat side and one side curved in). The plano concave lens is used as the eyepiece with the plano (flat) side facing the eye.
If kidney function begins to decline, BUN and creatinine rise. A normal creatinine depends on muscle mass and age. In general, a normal creatine is 0.5 to 1.2 milligrams per deciliter (mg/dL). A normal BUN is 7 to 20 mg/dL.
a measure of the amount of urea in the blood. Urea forms in the liver as the end product of protein metabolism, circulates in the blood, and is excreted through the kidney in urine. The BUN, determined by a blood test, is directly related to the metabolic function of the liver and the excretory function of the kidney. Normal findings (in mg/dL) are 10 to 20 for adults, 5 to 18 for children and infants, 3 to 12 for newborns, and 21 to 40 for cord blood.