By which pathway does oxygen flow into the body?
a)trachea, bronchioles, bronchial tubes, alveoli
b)trachea, bronchial tubes, bronchioles, alveoli
c)trachea, alveoli, bronchioles, bronchial tubes
d)trachea, alveoli, bronchial tubes, bronchioles

the endocrine system secretes hormones into blood and other body fluids. these chemicals are important for metabolism, growth, water and mineral balance, and the response to stress. hormones provide feedback to the brain to affect neural processing. reproductive hormones affect the development of the nervous system.