High Council of Sella
This hormone, also known as somatotropin, promotes growth of almost all tissues of the body that are capable of growing.
Growth Hormone
This trace element must be converted to its oxidized form to be utilized in the synthesis of thyroid hormones.
Iodine (Iodide)
This anabolic hormone promotes the storage of glucose as glycogen in the liver and muscle.
Insulin
This primary glucocorticoid is essential for the body's response to stress and the maintenance of blood glucose during fasting.
Cortisol
This androgen is the primary hormone secreted by the Leydig cells in response to Luteinizing Hormone (LH).
Testosterone
This hormone is the dominant steroid produced during the follicular phase to stimulate endometrial proliferation.
Estradiol (Estrogen)
Parathyroid hormone (PTH) acts to increase the plasma concentration of this divalent cation.
Calcium
Synthesized in the hypothalamus, this hormone increases water reabsorption in the collecting ducts of the kidneys by inserting aquaporin-2 channels.
Antidiuretic Hormone
Although Thyroxine is secreted in higher quantities, this hormone is roughly four times as potent in terms of biological activity.
Triiodothyronine
This glucose transporter, located in the membranes of beta cells, has a high Km, allowing it to act as a glucose sensor.
GLUT2
This mineralocorticoid acts on the principal cells of the late distal tubule to promote sodium reabsorption and potassium secretion.
Aldosterone
These cells provide the blood-testis barrier and secrete inhibin to provide negative feedback on FSH secretion.
Sertoli Cells
This massive increase in LH secretion is the physiological requirement for the occurrence of ovulation.
The LH Surge
PTH stimulates the kidneys to activate Vitamin D into this final, biologically active form.
activate Vitamin D into this final, biologically active form.1,25-dihydroxycholecalciferol (Calcitriol)
This large precursor glycoprotein is cleaved to produce ACTH, melanocyte-stimulating hormone (MSH), and beta-endorphin.
Pro-opiomelanocortin
This process involves the binding of iodine to the tyrosine residues of thyroglobulin to form MIT and DIT.
Organification
This hormone, secreted by alpha cells, primarily activates adenylyl cyclase in the liver to promote glycogenolysis.
Glucagon
This enzyme, found in the adrenal medulla, catalyzes the final step of converting norepinephrine to epinephrine.
Phenylethanolamine N-methyltransferase
In target tissues like the prostate, testosterone is converted to this more potent androgen by the enzyme 5-alpha-reductase.
Dihydrotestosterone (DHT)
This theory describes how Theca cells produce androgens while Granulosa cells convert them to estrogens.
The Two-Cell, Two-Gonadotropin Theory
PTH increases bone resorption by stimulating osteoblasts to express this ligand, which then activates osteoclasts.
RANKL (Receptor Activator of Nuclear Factor Kappa-B Ligand)
This hormone is the only anterior pituitary hormone controlled primarily by an inhibitory signal (dopamine) from the hypothalamus.
Prolactin
This enzyme is responsible for the peripheral conversion of T4 to the active T3 or the inactive reverse T3 (rT3).
Deiodinase
The insulin receptor belongs to this class of receptors, which undergo autophosphorylation upon ligand binding.
Receptor Tyrosine Kinase
This common precursor molecule is the starting point for the synthesis of all adrenal cortical steroids.
Cholesterol
This protein, secreted by Sertoli cells, binds to testosterone to ensure high concentrations remain within the seminiferous tubules.
Androgen-Binding Protein (ABP)
This enzyme, a member of the Cytochrome P450 family, is responsible for the conversion of androgens to estrogens.
Aromatase (CYP19)
In the renal tubules, PTH increases the reabsorption of calcium while simultaneously inhibiting the reabsorption of this ion.
Phosphate
In the somatotropic pathway, GH exerts much of its effect through this intermediate peptide, primarily synthesized in the liver.
Insulin-like Growth Factor 1
High levels of circulating iodide can transiently inhibit the organification of iodine, a physiological phenomenon known by this name.
The Wolff-Chaikoff Effect
This intracellular messenger, produced in the beta cell via ATP-sensitive K+ channel closure, triggers the exocytosis of insulin granules.
Calcium
A deficiency in this specific enzyme leads to Congenital Adrenal Hyperplasia, characterized by salt-wasting and virilization
21-hydroxylase
During the synthesis of testosterone, this enzyme is required to convert androstenedione into testosterone.
17 beta-hydroxysteroid dehydrogenase
Secreted by the Corpus Luteum, this hormone is essential for maintaining the secretory phase of the uterine cycle.
Progesterone
These receptors on the surface of parathyroid chief cells inhibit PTH secretion when bound by circulating calcium.
Calcium-Sensing Receptors (CaSR)