A very large loss of  from the patient will lead to a drastic decrease in pH.  Therefore, all alkalosis disorders can be ruled out.  Additionally, because the pH decrease is unrelated to an increase in carbon dioxide, it is not a respiratory issue - leaving only metabolic acidosis as a diagnosis.  Cystic fibrosis involves the overproduction of thick mucous, which causes severe respiratory pathology; other systems are affected too, but excess bicarbonate secretion is not associated with this genetic disease.

Obstruction bilaterally in the ureters leads to decreased GFR due to increased pressure retrograde from the ureters. Bowman space pressure increases to override the GFR pressure. Bowman space pressure does not favor filtration versus GFR pressure (favors filtration). 

Serum osmolality is best estimated at around 

When holding urine, there are two primary sphincters that help control the release of urine. The internal urethral sphincter is composed of smooth muscle, and is therefore not consciously controlled. The external urethral sphincter is composed of skeletal muscle, which means that it can be consciously controlled.

The detrusor muscle is the smooth muscle found in the walls of the bladder. When contracted, this muscle leads to urination. The rectus abdominis is a region of the abdominal wall. When contracted, this muscle can indirectly assist in urination by reducing the volume of the abdominal cavity and pressuring the bladder.

Because women have smaller urethras, bacteria and other pathogens have a shorter distance to travel in order to cause infections in the body. In addition, the proximity of the anus to the urethral opening in women is much closer compared to men, resulting in a closer proximity to bacteria.

Total body water is approximately 60% of body weight. The percentage of total body water is highest in newborns and adult males, and lowest in adult females and in adults with large amounts of adipose tissue (fat). Intracellular fluid is 40% of body weight, and extracellular fluid is 20% of body weight (60-40-20 rule).

Intracellular fluid (ICF) is two-thirds of total body water. Its major cations are  and . The major anions of ICF are proteins and organic phosphates (ATP, ADP, AMP). Also, most proteins carry a net negative charge at physiological pH. Major cations of extracellular fluid (ECF) are , its anions are  and . Remember that the sodium potassium pump works continuously to pump three sodium ions out of the cell and two potassium ions into the cell, thus concentrating these species in their respective compartments.

Extracellular fluid (ECF) contains the cation , and  and  as its anions.  ECF is one-third of total body water and is composed of interstitial fluid and plasma. Plasma is one-fourth of the ECF, thus it is one-twelfth of total body water (TBW).

Intracellular fluid (ICF) provides two-thirds of TBW. Its major cations are  and . The major anions of ICF are proteins and organic phosphates (ATP, ADP, AMP). Note that DNA also carries a net negative charge, and is intracellular, but not dissolved.

Saliva contains the enzyme alpha amylase. This enzyme is responsible for breaking down starch and carbohydrates into smaller polysaccharide chains.

Later, in the small intestine, pancreatic beta amylase further digests the carbohydrates until they can be absorbed into the blood. Most chemical digestion occurs in the small intestine, where enzymes to digest proteins, lipids, and carbohydrates are introduced to the digestive tract.

The mouth is the start of the gastrointestinal tract. It is the site of both mechanical and chemical digestion via chewing, and saliva, respectively. Saliva contains the enzyme amylase that breaks down carbohydrates.