Renal Function

Renal function analysis

Quickly assessed by measuring levels of nitrogenous watse in blood

Renal clearance

ability of the kidneys to clear solutes from the plasma

Inulin

a polysaccharide completely excreted by the kidney; used to measure kidney function

Clearance value and inulin

Clearance value less than inulin - substance is reabsorbed

Clearance value equal to inulin - no net reabsorption

Clearance value greater than inulin - tubule cells are secreting the substance into the filtrate

Chronic renal disease

defined as a GFR < 60 ml/min for 3 months

Filtrate formation decreases, nitrogenous wastes accumulate in blood, pH becomes acidic

Seen in diabetes mellitus and hypertension

Hemodialysis

the process by which waste products are filtered directly from the patient's blood

Abnormal urinary constituents

glucose, protein, ketone bodies, erythrocytes, leukocytes, bile pigments

Urine chemical composition

95% water and 5% solutes

Urea, Na+, K+, PO4-3, SO4-2, creatinine, uric acid

Urine physical characteristics

1) Color and transparency - yellow ish color; cloudy urine may indicate infection

2) Odor - develops ammonium odor if left

3) pH - about pH 6 usually, can range from 4-8

4) Specific Gravity -