Oxygen-rich blood flows a. through the pulmonary circulation.

b. through the systemic circulation,

C. from the lungs to the heart.

d. all of the above

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?

When writing fitness goals we encourage using the smart method. what does s-m-a-r-t stand for? use full sentences to explain what each letter stands for in their goals setting process.

What else happens in your cardiovascular system in response to your sympathetic nervous system? why might your blood vessels need to expand to accommodate this?