atrioventricular , <span>semilunar - When listening to the heart,</span><span> the examiner listens for the unique lup-dup sounds of the heart to understand if the heart is healthy. These sounds are generated when the heart beats to allow blood to flow throughout the body. The sound is basically created each time the heart valves snap shut. The "lub" is the atrioventricular valves snapping
shut and the "dup" sound occurs when the semilunar valves close at the
end of systole.</span>
<span>Geography effected the British advance on Philadelphia as the Appalachian mountains boarder's Philadelphia making it hard for British troops to get to Philadelphia. The climate and cold weather also had an effect on British troops.</span>
