What layers of the earth make up the lithosphere

these muscles maintain the blood pressure in the vessels. the smooth muscles are innervated by nerves of the autonomic nervous system. when the muscles contract, they cause vasoconstriction of the vessels and increase blood pressure. when the muscles relax, they enable vasodilation of the   blood vessels hence reduce blood pressure.  

answer;

medical directors

explanation;

medical directors grants and supervises the privilege or permission to use an aed on an ambulance.

other roles of a medical director includes;

-provide medical leadership, including coordination with local ems and 911 centers.

-provide guidance in equipment selection and deployment

-develop guidelines for responder actions

-oversee medical care that is rendered through the program, including review of all responses to medical emergencies

-ensure appropriate initial training and skill maintenance

-assume overall responsibility for the conduct and operation of all patient care related activities