Final answer:
Increased sympathetic stimulation and decreased parasympathetic stimulation result in the hypothalamus increasing cardiac output and resistance.
Step-by-step explanation:
The hypothalamus increases cardiac output and resistance in response to increased sympathetic stimulation and decreased parasympathetic stimulation. When sympathetic stimulation increases, the cardiac centers release norepinephrine and epinephrine, which bind to alpha and beta receptors on the cardiac muscle cell membrane, increasing the metabolic rate and force of contraction. This leads to an increase in stroke volume and a decrease in end-systolic volume, resulting in increased cardiac output. On the other hand, decreased parasympathetic stimulation decreases the release of acetylcholine, allowing heart rate to increase. Both of these actions increase cardiac output and resistance.