Which determinant affects blood pressure?

Which determinant affects blood pressure?

• A. Lung capacity.
• B. Hair color.
• C. Blood volume.
• D. Bone density.

Answer: (C)

Blood pressure is set by how much blood is circulating and how hard the heart pumps to move it. When blood volume is higher, more blood returns to the heart, increasing preload. The heart then pumps more strongly (Frank-Starling relationship), boosting cardiac output. With arterial pressure determined largely by cardiac output and vascular resistance, this higher output raises mean arterial pressure. So, blood volume directly influences blood pressure, making it the key factor in this set of choices. Lung capacity affects gas exchange and oxygen delivery but doesn’t set arterial pressure in a direct way; hair color and bone density don’t influence circulating pressure.

Blood pressure is set by how much blood is circulating and how hard the heart pumps to move it. When blood volume is higher, more blood returns to the heart, increasing preload. The heart then pumps more strongly (Frank-Starling relationship), boosting cardiac output. With arterial pressure determined largely by cardiac output and vascular resistance, this higher output raises mean arterial pressure. So, blood volume directly influences blood pressure, making it the key factor in this set of choices. Lung capacity affects gas exchange and oxygen delivery but doesn’t set arterial pressure in a direct way; hair color and bone density don’t influence circulating pressure.