By the start of the twentieth century, Germany and the United States had challenged some of Britain's economic lead. Subsequent military and economic tensions between Britain and Germany were major causes of the First World War, during which Britain relied heavily upon its empire.he British Empire comprised the dominions, colonies, protectorates, mandates and other territories ruled or administered by the United Kingdom.
A heart murmur is an extra or unusual sound heard during a heartbeat. Murmurs range from very faint to very loud. Sometimes they sound like a whooshing or swishing noise. Normal heartbeats make a lub-DUPP or lub-DUB sound.This is the sound of the heart valves closing as blood moves through the heart.Doctors can hear these sounds and heart murmurs using a stethoscope.ometimes they sound like a whooshing or swishing noise. Normal heartbeats make a lub-DUPP or lub-DUB sound. This is the sound of the heart valves closing as blood moves through the heart. Doctors can hear these sounds and heart murmurs using a stethoscope.
The mechanistic concept of the heart as a hydraulic pump prevailed and became firmly established around the middle of the nineteenth century. The heart, an organ weighing about three hundred grams, is supposed to `pump' some eight thousand liters of blood per day at rest and much more during activity, without fatigue. In terms of mechanical work this represents the lifting of approximately 100 pounds one mile high!