A&P Cardiovascular System Practice Test

Heart rate is controlled by autonomic centers in the brainstem, with the medulla oblongata housing the cardioacceleratory and cardioinhibitory centers that fine-tune rate through sympathetic and parasympathetic pathways. The parasympathetic output travels via the vagus nerve to slow the heart by acting on the SA and AV nodes, while the sympathetic output increases rate and contractility through signals that reach the heart. The medulla also integrates sensory input from baroreceptors to help maintain blood pressure. In contrast, the midbrain, thalamus, and cerebellum handle other functions and do not contain the primary autonomic cardiac control centers.