Answer:
in the wall of the right atrium of the heart.
Explanation:
The sinoatrial node (SA), consisting of spindle-shaped cells, initiates the electrical activity of the heart. From its location in the right atrium in proximity to the superior vena cava, the electrical activity spreads to the atria, whose cells are larger than those of the SA.
The main function of the respiratory system is to allow the exchange of gases between the atmosphere and the lungs.
Hence,the only structure that carries out this function is the alveoli as other structures such as the nose,trachea and pharynx transport gases to the alveoli just so that it can can out its function.
Answer:
<em><u>Nutrients help break down food to give organisms energy</u></em>
Explanation:
Nutrients are chemical substances found in every living thing on Earth. They are<em> necessary</em> to the lives of people, plants, animals, and all other organisms. <u><em>Nutrients help break down food to give organisms energy</em></u>. The human body can also synthesize some nutrients, such as <em>amino acids</em>.