Pneumococcal infections are caused by Streptococcus pneumoniae, a gram-positive, catalase-negative organism commonly referred to as pneumococcus.
Blood pressure is a measure of the changing fluid pressure within the circulatory system. It varies. from a peak pressure produced by contraction of the left ventricle, to a low pressure, which is. maintained by closure of the aortic valve and elastic recoil of the arterial system. The peak.
How To Measure Blood Pressure Blood pressure represents the force (pressure) exerted by blood against the arterial walls during a cardiac cycle. <kt>Systolic pressure<kt>, the higher of the two blood pressure measurements, occurs during ventricular contraction (systole) as the heart propels 70 to 100 mL of blood into the aorta. After systole, the ventricles relax (diastole), the arteries recoil, and arterial pressure continually declines as blood flows into the periphery and the heart refills with blood. The lowest pressure reached during ventricular relaxation represents <kt>diastolic pressure<kt>. Normal systolic blood pressure in an adult varies between 110 and 140 mm Hg; normal ...