Let's Test Your Endocrine System Skills

The posterior pituitary gland releases two hormones: oxytocin and antidiuretic hormone (ADH). Oxytocin is responsible for stimulating contractions during childbirth and promoting bonding and social behavior. ADH, also known as vasopressin, helps regulate water balance in the body by reducing urine production and increasing water reabsorption in the kidneys.

Androgen is the correct answer because it is a hormone produced by the adrenal glands that is responsible for stimulating the growth of facial and body hair. Cortisol is a hormone produced by the adrenal glands that helps regulate metabolism and stress. Estradiol is a female sex hormone produced primarily by the ovaries, and norepinephrine is a neurotransmitter produced by the adrenal glands that helps regulate blood pressure and heart rate.

Adrenocorticotropic hormone (ACTH) is secreted by the anterior pituitary gland and stimulates the production of cortisol by the adrenal cortex. Cortisol is a steroid hormone that plays a crucial role in regulating metabolism, immune response, and stress response. ACTH binds to receptors on the adrenal cortex, triggering the release of cortisol. Therefore, ACTH is the hormone responsible for stimulating cortisol production.

Luteinizing hormone is the correct answer because it stimulates the production of sex cells, specifically in males, it stimulates the production of testosterone in the testes, and in females, it stimulates ovulation and the production of progesterone and estrogen in the ovaries. Corticotropin, melanocyte stimulating hormone, growth hormone, and TSH do not directly stimulate sex cell production.

When a hormone is present in excessive levels, the number of target-cell receptors may decrease. This is known as down regulation. In this process, the target cells reduce the number of receptors on their surface in response to the high concentration of the hormone. This down regulation helps to prevent overstimulation of the target cells and maintains homeostasis in the body.

Calcitonin is the hormone that opposes the action of parathyroid hormone. Parathyroid hormone is responsible for increasing calcium levels in the blood, while calcitonin decreases calcium levels. Therefore, calcitonin works in opposition to parathyroid hormone by inhibiting the release of calcium from bones and promoting calcium excretion by the kidneys.

The five types of anterior pituitary cells secrete a total of 7 hormones. This suggests that each type of cell is responsible for secreting at least one hormone, with some cells potentially secreting more than one. The answer of 7 indicates that there are a limited number of hormones secreted by these cells, rather than an unlimited amount.

Both prostaglandins and leukotrienes are major eicosanoids. Eicosanoids are signaling molecules that are derived from arachidonic acid, a fatty acid found in cell membranes. Prostaglandins and leukotrienes play important roles in inflammation, immune response, and various physiological processes. Prostaglandins are involved in regulating blood flow, hormone regulation, and inflammation, while leukotrienes are involved in allergic and inflammatory reactions. Therefore, the correct answer is "Both a and b."

Hydrolysis of calcium is not part of the process used to synthesize and secrete T3 and T4. The synthesis of T3 and T4 involves several steps, including iodide trapping, oxidation of iodide, coupling of T1 and T2, and iodination of tyrosine. Calcium hydrolysis, on the other hand, refers to the breakdown of calcium compounds into calcium ions and hydroxide ions, which is not directly involved in the synthesis and secretion of thyroid hormones.

Hormone secretion is regulated by various factors, including signals from the nervous system and chemical changes in the blood. The peripheral nervous system is not directly involved in regulating hormone secretion. Instead, it is the central nervous system that plays a role in regulating hormone release. Therefore, signals from the peripheral nervous system are not a way hormone secretion is regulated.