What is the physiology underlying the changes in mean arterial pressure and heart rate that occur with changes in posture?

Blood Fall ; Gravity. Person curious about physiologic changes in body going from supine to upright should regard faster ; more vigorous heart beats to pump blood ; oxygen to neediest tissue, the brain, which resides on highest part of the body tower. Blood column falls farther in an upright body, thereby causing arterial constriction to acutely diminish size of the blood container, the arterial system.

Related Questions

What is the physiology that explains how a high heart rate influences coronary artery perfusion and myocardial oxygen delivery?

Circular question. By itself, a high heart rate will result in higher oxygen demand and utilization, but delivery should also increase to compensate. So everything should balance if the heart is healthy. If the heart isn't healthy to begin with a high heart rate is not desirable. Read more...

Coronary artery calcification...I take adalat (nifedipine) blood pressure ok but heart rate high 110 at rest. Feel heaveness on chest and shortness of breath. Help?

Need examination. That is an abnormal resting heart rate and for someone your age & history of coronary artery calcification as you state- if this is entirely new for you in terms of symptoms then, your next move should be an ER facility. You are welcome to write to me with other questions if you'd like at: www.healthtap.com/drsaghafi but I don't think that should delay getting seen now. Read more...

Expert opinions? Which changes in blood pressure and heart rate occur due to depression of the brainstem vasomotor centre from phenobarbital overdose?

Respiratory. Main issue with Phenobarbital is decreased respiratory drive with secondary apnea, which is the main mechanism of death, and this due to suppression of fourth ventricular receptors. Pulse and blood pressure changes would be secondary to the main issue. Read more...

Blood pressure my husbands blood pressure is staying at 195 over 90. He's on 3 different medicine and no change. His heart rate is 47 BPM please help?

Needs a work up. For secondary causes for hypertension. His b/p is obviously still way to high and his pulse is too low. He needs blood work and a renal artery scan for starters. Read more...
See a specialist? First of all, does he actually take all his medication, and has he checked his own blood pressures at home or outside the doctor's office to check for "white coat" hypertension? Also, diet (high salt or alcohol), other medications ( such as advil-like antiinflammatory drugsl), or herbal supplements could interfere. He might need to see a blood pressure specialist if no response to 3 rx's. Read more...
High BP. If your husband is compliant with his medications and his BP is not controlled, he may have secondary hypertension (sh). Sh can be caused by various factors and these can be discussed with him by a nephrologist (n). His BP is alarmingly high and needs to be treated. His low pulse may be due to a beta-blocker. If he has sh and it is treated he will be much more healthy. See a n quickly. Read more...

What does it mean when you have low blood pressure but a high heart rate?

Need evaluation. Elevation in heart rate can be a compensatory change in the setting of low blood pressures. Cause cannot be determined without knowning the actual readings and without a thorough evaluation. Read more...