Donna was riding her horse on a warm sunny day (101 degrees Fahrenheit). Donna began to feel overheated, sweaty, and exhausted when suddenly her horse stopped and reared up in the air. Donna was not prepared for this and fell hard backwards into the ground. As she hit the ground her leg was gashed open by a large, sharp boulder. Through the cut Donna's friend Jane could see her femur. As Donna's leg began to bleed severely and before they could get to the hospital an infection began in her skin. For this case :
i. Identify the anatomy/physiology involved as related to the Integumentary System
ii. What is going wrong or has occurred, and how that impacts the Integumentary System specifically.
iii. Provide an explanation for how the Integumentary System responds to the situation.

The kidney filters potentially toxic substances in the blood, and thus “clears” the blood of those substances. this clearance function is dependent upon and proportional to the diffusion gradient of the substance across filtering capillaries, i. e. if the concentration of the substance is doubled, twice as much will be cleared from each ml of blood that is filtered. suppose that the body produces a constant amount of a substance x per unit of time. the kidneys eliminate substance x at a rate directly proportional to the concentration of the substance and the volume of blood cleared each minute (c): elimination = c × [x], where [x] is the steady-state concentration of substance x. imagine an individual with an initial concentration of x equal to [x]0 who develops kidney disease. her baseline clearance c0 drops to one half of the original (½c0). what is the new steady state concentration of x? (for simplicity, assume that substance x is 100% filtered by the kidney).