Skeletal muscles play a key role in the movement of blood around the body. Veins embedded within a muscle are compressed during contraction of that muscle, causing an increase in blood pressure due to the presence of one-way valves within the veins.
The answer is C, because it has a negative charge -1. All groups with charges called ions, unless they are organic compounds.
Answer:
Las hormonas pertenecen al grupo de los mensajeros químicos, que incluye también a los neurotransmisores y las feromonas. A veces es difícil clasificar a un mensajero químico como hormona o neurotransmisor.
Todos los organismos multicelulares producen hormonas, incluyendo las plantas (En este último caso se denominan fitohormonas).
Explanation:
B - They both use protein channels (I think so at least) they differ because active transports use a pump to leave the cell and it uses atp (cell energy).