The following answer choices are all examples of anterior pituitary hormones, however, follicle-stimulating hormone (FSH) is the hormone that acts on Sertoli cells in the testes to nourish sperm and facilitate spermatogenesis.

Luteinizing hormone (LH) acts on the testes, but works on Leydig cells in producing testosterone. Adrenocorticotropic hormone (ACTH) and thyroid-stimulating hormone (TSH) do not act on the testes.

The parasympathetic nervous system is responsible for the "rest and digest" functions of the body. When digesting, the body will be storing nutrients, converting them to fat and glycogen in the liver and other tissues of the body. Insulin is responsible for the lowering of blood glucose levels and storing glucose as glycogen in the liver.

All the other hormone options would be seen when the body is active and under stress. Cortisol is triggered during long-term stress, while epinephrine is secreted in response to an immediate threat. Aldosterone is raised when water levels in the body are low, a sign of possible dehydration or drought.

When blood glucose is high, beta cells of the islets of Langerhans in the pancreas sense the high glucose and release insulin. Insulin binds to cells throughout the body and encourages production of additional glucose transporters on the cell surface in order to take up more glucose from the blood.

Glucagon, in contrast, is secreted when glucose levels are low and acts to prevent glucose uptake from the blood. It also stimulates gluconeogenesis and glycogenolysis.

When blood glucose is low, alpha cells of the islets of Langerhans in the pancreas sense the low glucose and release glucagon. Glucagon acts to prevent glucose uptake from the blood and stimulates gluconeogenesis and glycogenolysis in the liver.

In contrast, insulin binds to cells throughout the body when glucose levels are high. Insulin encourages production of additional glucose transporters on the cell surface in order to take up more glucose from the blood.

A decreased blood glucose level would cause growth hormone, glucagon, and cortisol release to protect from the effects of hypoglycemia. Growth hormone promotes cell replication, which indirectly stimulates other pathways to create free glucose. Glucagon increases glucose levels by stimulating gluconeogenesis in the liver and glycogen breakdown in the liver. Cortisol acts to increase free fatty acid levels and increases gluconeogenesis.

Insulin promotes glucose sequestration, further decreasing blood glucose.

Calcitonin, produced by the thyroid, decreases (or "tones down") the blood calcium level. Calcitonin decreases the amount of calcium in the blood by inhibiting the activity of osteoclasts, which break down bone and release calcium in the bloodstream. By inhibiting osteoclasts, calcitonin directly reduces the blood calcium level.

Parathyroid hormone, released by the parathyroid gland, increases the blood calcium level. Parathyroid hormone stimulates osteoclasts to break down bone and release calcium into the bloodstream. Insulin and glucagon are produced by the pancreas and are responsible for the regulation of blood glucose levels. Insulin lowers blood glucose and increases glycogen stores, while glucagon increases blood glucose by stimulating the conversion of glycogen to glucose in the liver. 

Significant amount of blood loss results in a sudden and large drop in blood pressure due to the decreased fluid volume in the body. To compensate for this change, the body will attempt to increase fluid retention. This is directly accomplished by increasing the level of ADH (anti-diuretic hormone) that allows reabsorption of water in the kidneys. Therefore, increased ADH level is the best response.

All of the following are examples of the effects that elevated blood cortisol levels have on the body's metabolism. Cortisol is glucocorticoid that is released in response to stress. One main function of cortisol is also to elevate blood glucose levels after long periods of fasting. Glycogenesis is incompatible with this effector response, and thus is the correct answer.

When the body is dehydrated, the posterior pituitary will secrete antidiuretic hormone (ADH). ADH binds to the collecting tubules to allow for water to be reabsorbed.  

The anterior pituitary releases thyroid-stimulating hormone (TSH) which binds to receptors on the thyroid gland and promote the synthesis of the thyroid hormones T3 and T4. Excess stimulation of the thyroid gland due to high level of TSH will cause the thyroid to enlarge and result in an observed goiter.