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Biology-Related Homework Help Anatomy and Physiology Topic started by: leighann1023 on Mar 25, 2013



Title: what are the effects the posture on systolic and diastolic blood pressure?
Post by: leighann1023 on Mar 25, 2013
what are the effects the posture on systolic and diastolic blood pressure?


Title: what are the effects the posture on systolic and diastolic blood pressure?
Post by: smjsa79 on Mar 25, 2013
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Title: what are the effects the posture on systolic and diastolic blood pressure?
Post by: datha on Mar 25, 2013
When you lie down, Mean Arterial Pressure increases. This is because when you lie down flat, blood tends to flow easily to the heart. Therefore more blood returns to the heart. And then this causes the heart muscle fibres to stretch, causing it to contract harder (frank- starling mechanism).

However in the upright position, due to an action of gravity, it is harder for blood to work against gravity and return to the heart. So lesser venous return, decreased contractility and lower sys di blood pressure.