Explain how a rise in blood pressure results in a decrease in the rate of heartbeat.
Baroreceptors detect the rise in blood pressure in the aorta, they send impulses to the cardiovascular centre. Then, impulses are sent via parasympathetic nerves to the SAN. This triggers the release of ACh, this decreases the frequency of impulses to the AVN. As a result the rate of atrial and ventricular contraction is lower, so the "heartbeat" is slower.
KS
Related Biology A Level answers
All answers ▸What are phagocytes and how do they protect the body?
Describe how genetic fingerprinting is carried out? (example of 6-mark question)
Describe the Benedict's test for reducing sugars and how this can be modified to test for non-reducing sugars
How is DNA packaged within Eukaryotic Cell nucleosomes