Question

96. Choose the false statement:

A. The blood passing through the aortic valve is high in oxygen; blood passing in the pulmonary artery is low in oxygen.

B. When the pH decreases in a tissue both arteriolar smooth muscle cells and pre-capillary sphincters will respond by contracting.

C. Blood pressure is the product of cardiac output and peripheral resistance; BP will decrease if heart rate decreases, if venous return is diminished, or if arterioles undergo vasodilation.

Answer 1

Answer 96:

Statement A is correct. Aortic valve lets oxygen rich blood from left ventricle of heart to enter the aorta. Pulmonary artey carries deoxygenated blood from heart to lungs.

Statement C is correct, as blood pressure is dependent on cardiac output and peripheral resistance. If blood return to heart is decreased, then there will be lesser blood to pump. This will reduce blood pressure. Similarly, when heart rate reduces the pressure of blood in vessels also reduces. Vasodilation broadens the vessels, due to which there is more space for blood to flow. This also reduces blood pressure.

The false statement is B:

When the pH decreases in a tissue both arteriolar smooth muscle cells and pre-capillary sphincters will respond by contracting.