Important question please answer. IS the BPM of 54 for a 13 year old girl normal? IM 13 and my bpm has been 54 and sometimes 50

Cultural, economic , and social changes that resulted in the migration of more people into cities - utilitarianism -industrial revolution -age of enlightenment

As you sit in the library with your friend studying for your weekly quiz on the integumentary system, you come upon an article about the hazards of prolonged exposure to the sun's rays. your curious nature leads you to research the subject further. you're fascinated to learn that minimal exposure to the sun allows you skin to manufacture vitamin d, which is important to maintain homeostasis. you also read that although sunscreen can protect you from the ultraviolet (uv) rays of the sun, some medications can actually increase a person's sensitivity to the sunlight.

Felicia has a respiratory infection and has been coughing up a lot of mucus. she knows this means that her respiratory system is working to restore balance by getting rid of the invasive materials from her lungs. how does this happen?