What directs the rate of breathing?

What are the three most common STDs? What is the role of the blood vessels on the outside of a heart? Why doesn't blood clot in the bottles in Blood banks? What happens when the smegma under the foreskin is not cleaned often can you get anything like chlamydia or stuff like that? The type of epithelial cells most commonly associated with absorption is the small intestine is what? In a living animal what body movements draw air into the lungs? Can color blindness be treated or cured? Do gallstones cause physical discomfort? What brings blood to the lungs for gas exchange? What portion of the brain controls rationalization? Would a blood test taken 5 days after ovulation be accurate? How does mucus affect food in the digestive system? What is an arrhythmia pulse? What is an RE-4 discharge? What part of the body does mad cow disease effect? How big should your breasts be before you get a bra? Can stress make your eyes bleeding? What gender is more likely to get autism? Im 38 weeks pregnant and getting sharp pains and a lot of pressure down below and on ma lower back the doctor said her head is quite far down now and i keep waking up really early in the mornin? What are the categorys of endocrine gland stimulus?