NEETZoologyBody Fluids and Circulation
What is the function of the Sino-atrial node (SAN) in the heart?
Options
- ATo control blood pressure
- BTo control heart rate
- CTo control the stroke volume
- DTo control the blood flow
Correct answer
B. To control heart rate
Step-by-step solution
The nodal musculature has the ability to generate action potentials without any external stimuli, i.e., it is autoexcitable. However, the number of action potentials that could be generated in a minute vary at different parts of the nodal system. The SAN can generate the maximum number of action potentials, i.e., 70-75 min–1, and is responsible for initiating and maintaining the rhythmic contractile activity of the heart . Therefore, it is called the pacemaker. Our heart normally beats 70-75 times in a minute (aver