Reduces should be the answer
Answer:
SA node
Explanation:
The SA node (called the pacemaker of the heart) sends out an electrical impulse. The upper heart chambers (atria) contract. The AV node sends an impulse into the ventricles. The lower heart chambers (ventricles) contract or pump.
Answer: <span>Normal microbiota directly kill invading organisms.
Some bacteria that reside in our body are useful to combat pathogenic microorganisms. Those bacteria, like lactobacillus and E.coli, inhibit the growth of those pathogenic organisms by taking, for example, oxygen and nutrients from them, or even changing the local ph. They can also produce metabolites that make the environment impossible to live for the intruders.
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A compound consists of two or more elements.
