Vasopressin (antidiuretic hormone) is responsible for placing aquaporin channels on the collecting ducts of the kidney to allow for increased water reabsorption. This increased water reabsorption allows for blood pressure to be maintained. Interestingly, coffee and alcohol are vasopressin blockers, causing a large increase in urine volume when ingested.

Aldosterone, in contrast, causes a retention of sodium ions, which indirectly draws water out of the filtrate to concentrate the urine. Aldosterone does not affect permeability of the collecting duct to water. Renin indirectly leads to increases in both vasopressin and aldosterone, but has no direct effect on the collecting duct by itself.

Prolactin is responsible for stimulating milk production in women. While other hormones need a stimulus to trigger secretion, prolactin is tonically secreted, but its action is stopped by the neurotransmitter dopamine. During the period of nursing, the stimulus of the baby suckling inhibits dopamine, allowing for the release of prolactin and the production of milk.

Thyroid-stimulating hormone is produced by the anterior pituitary, and is responsible for stimulating T4 (tetraiodothyronine) and T3 (triiodothyronine) release from follicular cells in the thyroid gland. Too much thyroid-stimulating hormone can cause large lumps in the neck due to thyroid gland inflammation, called goiters. Goiters commonly result from an iodine deficiency, as the structures of both T4 and T3 require a central iodine atom.

Thyrotropin-releasing hormone is responsible for stimulating release of thyroid-stimulating hormone. Parathyroid hormone is important for regulating blood calcium, while growth hormone is involved in mitotic stimulation and nutrient balances.

Follicle-stimulating hormone is responsible for stimulating estrogen synthesis in the female ovaries.

Luteinizing hormone acts on Theca cells to stimulate androstenedione production (the precursor to estrogen), then follicle-stimulating hormone acts on granulosa cells to stimulate estrogen production. Both luteinizing hormone and follicle-stimulating hormone are required for estrogen production, but follicle-stimulating hormone is ultimately required for estrogen synthesis and secretion.

The function of antidiuretic hormone, or vasopressin, is to reabsorb water in the kidney tubules, thereby retaining water in the body. After dehydration, the camper's antidiuretic hormone levels would be high in order to preserve the water in his or her body.

Glucocorticoids, such as cortisol, have various functions; they reduce inflammation and prepare the body for long-term stress. Dehydration signals the body to prepare for long-term stress, increasing glucocorticoid levels.

Aldosterone increases sodium retention, drawing water out of filtrate and acting to counter dehydration. We would expect aldosterone to be elevated.

Insulin lowers blood glucose, but the camper would need to use glucose as energy causing this hormone to be decreased.

Renin, as the passage establishes, is an enzyme. Enzymes always work by leaving the thermodynamic energies of the products and reactants the same, but lower activation energy of the reaction. Angiotensinogen is released by the liver, and converted by renin to angiotensin I. Renin does not directly act on the liver to stimulate angiotensinogen release.

The LH surge, a spike in levels of luteinizing hormone, immediately precedes the luteal phase of the menstrual cycle, which begins with ovulation and ends with degeneration of the corpus luteum.

Estradiol, an estrogen, is secreted by theca cells and promotes growth of the endometrium to prepare for implantation.

Follicle-stimulating hormone is important for follicle maturation.

Degeneration of the corpus luteum into corpus albicans occurs in the absence of implantation. This degeneration process typically occurs 14 days after ovulation.

Human chorionic gonadotropin is only released during pregnancy and is responsible for maintaining the corpus luteum.

Calcitonin decreases blood calcium levels, while parathyroid hormone increases blood calcium levels.

FSH, LH, estrogen, and progesterone all increase around ovulation to make an environment in the uterus that will be healthy if fertilization occurs. Prolactin promotes milk production at the end of pregnancy and while a mother is breast feeding a child.

Release of ADH would not be associated with release of atrial naturitic hormone. ADH increases blood pressure, while atrial naturitic hormone decreases blood pressure.