Table 1.

Comparison of components between cerebrospinal fluid and plasma.

Component	Plasma	Cerebrospinal Fluid
Na+ (mmol/L)	153	135–150
K+ (mmol/L)	4.7	2.6–3.0
Ca2+ (mmol/L)	1.3	1.0–1.4
Mg2+ (mmol/L)	0.6	1.2–1.5
Cl− (mmol/L)	110	115–130
Protein (g/L)	60–80	0.15–0.45
Glucose (mmol/L)	3.9–5.5	2.8–4.4
pH	7.4	7.3
Osmolality (mOsm/kg H2O)	290	290

Legend for Table 1: Ca²⁺—calcium ions; Cl⁻—chloride ions; H⁺—hydrogen ions; H₂O—hydrogen monoxide, water; K⁺—potassium ions; Mg²⁺—magnesium ions; Na⁺—sodium ions; pH = −log[H⁺].