Describe and explain the effect of an increase in muscular activity on the heart rate.

An increase in muscular activity increases the rate of aerobic respiration. As a result, more carbon dioxide is formed in the Krebs cycle and the pH is lowered. This reduction in pH is detected by chemoreceptors found in the wall of the caratoid arteries (the arteries that serve the brain), which increase the frequency of impulses that they send to the medulla oblongata in the brain. The centre of the medulla oblongata that speeds up heart rate then, in turn, increases the number of impulses to the sinoatrial node via the sympathetic nervous system. Therefore, the sinoatrial node produces electrical waves at a faster rate and the heart rate increases.

Answered by Shauna W. Biology tutor

3160 Views

See similar Biology A Level tutors

Related Biology A Level answers

All answers ▸

What is the difference between the primary and secondary immune response?


What is the difference between a nerve synapse and a neuromuscular junction?


Using the Hardy Weinberg principle, calculate the frequency of the heterozygous genotype in the population if the frequency of the dominant allele p is 0.864. Express your answer as a percentage of the population.


Describe and explain the structure of the human heart.


We're here to help

contact us iconContact usWhatsapp logoMessage us on Whatsapptelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo

© MyTutorWeb Ltd 2013–2025

Terms & Conditions|Privacy Policy
Cookie Preferences