13 下列關於唾液（saliva）之敘述，何者正確？

 通常呈現酸性 為一種高張（hypertonic）液體

 內含鉀離子（K+）濃度比血漿內高 內含鈉離子（Na+）濃度比血漿內高

ans 通常呈現酸性 and內含鉀離子（K+）濃度比血漿內

Electrolytes:

• 2-21 mmol/L sodium (lower than blood plasma)
• 10-36 mmol/L potassium (higher than plasma)
• 1.2-2.8 mmol/L calcium (similar to plasma)
• 0.08-0.5 mmol/L magnesium
• 5-40 mmol/L chloride (lower than plasma)
• 25 mmol/L bicarbonate (higher than plasma)
• 1.4-39 mmol/L phosphate
• Iodine (mmol/L usually higher than plasma, but dependent variable according to dietary iodine intake)