The two function are Protection, Contains sensory receptors, production of vitamin D, regulation of body temperature I got only that
1. <span>The North Star, or Polaris, is the brightest star in the constellation Ursa Minor, the little bear (also known as the Little Dipper). As viewed by observers in the Northern Hemisphere, Polaris occupies a special place. The point in the night sky where the projection of the earth's axis lies is known as the North Celestial Pole (NCP). As the earth rotates on its axis (once every 24 hours), the stars in the northern sky appear to revolve around the NCP. Polaris lies roughly one half degree from the NCP, so this particular star appears to remain stationary hour after hour and night after night. 2.</span>
Answer:
Excitation is the process in which action potentials in the nerve fiber lead to action potentials in the muscle fiber. There is then a rapid fluctuation in membrane voltage at the motor end plate, called the end-plate potential. Areas of the sarcolemma near the motor plate have gates that open, moving ions, which causes the action potential that excites the muscle fiber. The process begins with a nerve signal stimulating a voltage-gated calcium ion channel to open, allowing the ions to enter the axon terminal. The ions stimulate the release of acetylcholine into the synaptic cleft.
