Question

pH of blood in arteries and veins
A. Higher in arteries and lower in veins
B. Higher in veins and lower in arteries
C. Same
D. Variable in both

Answer 1

The pH of blood is an important property. It is defined as its degree of acidity or alkalinity. Any solution's acidity or alkalinity including blood, is indicated on the pH scale. The pH scale ranges from 0 (strongly acidic) to 14 (strongly basic or alkaline). A pH of 7.0 is neutral which is in the middle of this scale. Blood has a normal pH range of about 7.35 to 7.45 which is normally slightly basic. Generally the body maintains the pH of blood close to 7.40.

Complete answer:
Body's Acid-base balance is defined as the balance between acidity and alkalinity.
The blood's acid-base balance is precisely controlled because it is necessary for the body as even a minor deviation from the normal range can severely affect many organs. The body uses different mechanisms to tackle the blood's acid-base balance.
The pH of blood refers to how acidic or basic it is. If there is any change in blood pH then it can be a signal of underlying medical issues.
The pH scale or acid-base scale, runs from 0 to 14. This scale measures how acidic a solution of a substance in water is. For example, pure water has pH=7.
If a solution has a low pH, then it will have a high concentration of hydrogen ions and is acidic. Whereas if a solution has a high pH, it will have lower concentration of hydrogen ions and are alkaline, or basic.
The pH scale is a very compact scale, and slight changes in pH represent big leaps in acidity.
Generally the pH of blood in the arteries is in the range of about 7.35 and 7.45 for the body’s metabolic processes and other systems to work well. The body has a complex system of feedback and regulation to maintain healthy pH levels.
Whereas the average mixed venous blood pH is 7.15.
So the pH of blood in arteries is greater than veins.

So option A. Higher in arteries and lower in veins is the correct answer.

Note:
Metabolic acidosis is defined as a condition when the blood is too acidic (pH below 7.35) due to too little bicarbonate, a condition called primary bicarbonate deficiency. In a healthy individual at the normal pH of 7.40, the ratio of bicarbonate to carbonic acid buffer is 20:1 and If a person’s blood pH drops below 7.35, then the person is in metabolic acidosis. The major cause of metabolic acidosis is the presence of organic acids or excessive ketones in the blood.