Nerve impulses are caused by Potassium (K+) and Sodium (Na+) ions that are located inside and outside of the cell. The structure of the cell membrane is permeable to Potassium but are highly impermeable to Sodium ions. These impulses are transmitted from one nerve cell to the other in very fast series.
Answer:
d. lead
Explanation:
Sulfur, Hydrogen and Oxygen are found in amino acids.
The exchange takes place in the millions of alveoli in the lungs and the capillaries that envelop them. As shown below, inhaled oxygen moves from the alveoli to the blood in the capillaries, and carbon dioxide moves from the blood in the capillaries to the air in the alveoli. You can see more in wikipedia, or here: https://www.merckmanuals.com/home/lung-and-airway-disorders/biology-of-the-lungs-and-airways/exchanging-oxygen-and-carbon-dioxide
