IB Biology: C3.1-Feedback Control of the Heart

Front

What is the role of the sinoatrial node (SAN) in the heart?

Back

The sinoatrial node (SAN), also known as the pacemaker, initiates its own action potentials and is controlled involuntarily by the cardiovascular centre (CVC) of the medulla oblongata in the brain.

Front

How does the cardiovascular centre (CVC) in the brain control heart rate?

Back

The CVC receives sensory inputs from baroreceptors and chemoreceptors, and sends impulses to the SAN to adjust the heart rate based on blood pressure, O2, CO2, and pH levels.

Front

What do baroreceptors monitor and how do they affect heart rate?

Back

Baroreceptors monitor blood pressure changes. When blood pressure increases, they send impulses to the CVC, which then sends impulses to the SAN to decrease the heart rate. When blood pressure falls, the heart rate increases.

Front

What role do chemoreceptors play in heart rate regulation?

Back

Chemoreceptors monitor O2, CO2, and pH levels in the blood. Low O2 and low pH levels cause the heart rate to increase, while high O2 and high pH levels cause the heart rate to decrease.