During hypovalemic shock, what are physiological change one ancounters, and what develop to bp, hr, resp & why

Loss of approximately one-fifth or more of the normal blood volume produces hypovolemic shock. Symptoms: speedy pulse
pulse may be weak (thready), hyperventilation, anxiety, cool, clammy skin, poor quality, pale skin color (pallor), sweating , moist skin, decrease or no urine output, low blood pressure,
confusion, unconsciousness
Blood pressure initially decrease due to the loss of volume - but the body will try to compensate by constricting all divergent arteioles (this pulls blood away from the surface of the skin - which is why you are pale and clammy).the heart will hit faster - to try to compensate for the loss of blood - i.e. bring up the blood pressure, your breathing rate will increase to try to compensate for the loss of oxygen (from the loss of blood and therefore the loss of hemoglobin for carrying oxygen).
The urine output will end - because the body is trying to hold onto as much liquid as it can, confusion because of decrease oxygen.