Heart rate. <span>From this site, the two channels of the autonomic nervous system originate the sympathetic and parasympathetic components. The sympathetic components increase heart rate by releasing the neural hormone catecholamines - epinephrine and norepinephrine. These hormones are cardio accelerators. Acceleration of the heart rate is called tachycardia.</span>
<span>During photosynthesis, plants use carbon dioxide and produce oxygen. During metabolism oxygen is used and carbon dioxide is a product. Humans impact the carbon cycle during the combustion of any type of fossil fuel, which may include oil, coal, or natural gas.</span>
Answer:
part A is the answer
Explanation:
The tympanic cavity is an air chamber; it contains a chain of movable bones which transmit the vibrations of the tympanic membrane across the cavity to the middle ear.
