Why does it mean if someone’s lower leg feels weighted and painful whenever they stand up?

True or false? the usa has one of the safest food supplies in the world

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?

What else happens in your cadriovascular in resonse to your sypathetic nervouse system?