Shock, Explained.

*Nerd Alert!* Today's topic is quite science-y and medically, but (hopefully) still interesting! 

Have you heard of people going into shock?  Shock signifies cardiovascular collapse. Blood has stopped pumping. Blood is not reaching vital organs. The circulatory system (basically) shut down. Shock can be triggered by a loss of blood (aneurism, cut, trauma, etc), a major loss of fluid (diarrhea, vomiting, dehydration, etc), an allergy (anaphylactic), or due to a spinal cord injury. 

Here is an overview of what is going on:

- The shock pathway starts with a loss of blood or fluid triggers hypovolemia (body senses a low volume) OR...
...an allergy or spinal injury triggers vasodilation (dilation of the veins) in the body
- Either of these triggers (vasodilation OR hypovolemia) cause decreased blood flowing back to the heart (because all of the blood is pooling in the dilated veins away from the heart OR there is not enough fluid to have blood go back to the heart)
- With a decreased amount of blood going to the heart, the heart rate decreases, meaning less blood is being pumped overall.
- Without blood, the body dies! Death from circulatory failure. Thus compensatory mechanisms kick-in as soon as the body reaches the "shock" status.
- Blood vessels in non-vital organs and body parts constrict, preventing blood from going to these parts, saving what blood remains for the vital organs.  This is why shock patients look pale and the skin feels cold/clammy; blood has been diverted away from the skin and blood is what our skin warm and flesh-toned (in the case of Caucasions).
- The kidneys try to conserve water by decreasing the amount of water that leaves the body via urine (uremia).
- If the root problem isn't fixed, taking the body out of a state of shock, then the patient can die from circulatory failure.  Before death, however, parts of the body can start to die from lack of blood (necrosis, seen most notably the intestines and the lungs).