Endocrine System Hormones and Their Functions

ADH

Released from: posterior pituitary; It's target: kidney; Effect on target: increase water absorption, reduce urine volume; Regulation of release: hypothalamus reg. In response to changes in the osmotic pressure of the plasma.

Oxytocin

Released from: posterior pituitary; It's target: uterine (female reproductive system); Effect on target: Increase contraction during childbirth and increase milk production; Regulation of release: positive feedback for childbirth.

ACTH

Released from: Anterior pituitary; It's target: adrenal glands; Effect on target: produces glucocorticoids, regulates metabolism and stress response, stim. Adrenal cortex, and stim cortisol release; Regulation of release: increase in release of glucocorticoids goes through negative feedback loops.

TSH

Released from: TRH releasing hormone: anterior pituitary; It's target: Thyroid gland; Effect on target: stimulates release of thyroid hormone (TH) regulates metabolism; Regulation of release: Negative feedback of T3 and T4, thyroid hormone levels.

GH

Released from: GHRH releasing hormone, anterior pituitary; It's target: liver, bones, and muscles; Effect on target: regeneration, stimulates growth, cell regeneration and reproduction. Promotes IGF - 1 from the liver; Regulation of release: GHRH from hypothalamus, inhibit from high IGF-1 and somatostatin.

Prolactin

Released from: PRH releasing hormone, anterior pituitary; It's target: mammary glands; Effect on target: milk production; Regulation of release: dopamine restrains prolactin production, stim by PRH from hypothalamus.

FSH

Released from: GnRH = releasing hormone, anterior pituitary; Target: reproductive system (ovaries and testes); Effect on target: stimulates production of sperm and eggs; Regulation of release: stim. By GnRH from the hypothalamus, regulated by inhibin estrogen and testosterone levels.

LH

Released from: GnRH = releasing hormone, anterior pituitary; Target: reproductive system (ovaries and testes); Effect on target: stim. Production of sex hormones by gonads; Regulation of release: negative feedback from the testes and ovaries.

Inhibin

Blocks the release of LH.

ANP (Atrial Natriuretic Peptide)

Released from the heart; targets blood vessels and kidneys; effects include vasodilation, decrease BP, and increase urination (sodium and water secretion); regulated by baroreceptors in the heart detecting increased BP.

Epinephrine/Norepinephrine

Released from adrenal medulla; targets the whole body; effects include increasing heart rate, blood pressure, blood glucose levels, and dilating airways; regulated by the sympathetic nervous system.

Cortisol

Released from the fasciculata layer of adrenal cortex; targets liver and immune system; effects include release of sugar from the liver, altering fat distribution, and suppressing the immune system; regulated by stress response in the brain resulting in ACTH release.

Aldosterone

Released from the glomerulosa layer of adrenal cortex; targets kidneys; effects include retaining salt and water, which increases BP; regulated by the renin-angiotensin-aldosterone mechanism.

Androgens

Released from the reticulata layer of adrenal cortex; targets all over the body; effects include development of secondary masculine sex characteristics.

EPO (Erythropoietin)

Released from kidneys; targets RBCs and bone marrow; stimulates stem cells of bone marrow to increase production of RBCs during low oxygen; regulated by negative feedback once RBCs return to normal count.

Renin

Released from kidneys; targets bloodstream; aids in production of angiotensin II, leading to fluid retention and increased BP; regulated by baroreceptors in juxtaglomerular cells detecting decreased BP.

Leptin

Released from white adipose tissue; targets brain (hypothalamus); inhibits hunger; regulated by insulin and negative feedback.

Melatonin

Released from pineal gland; targets various tissues (brain); effects include regulating sleep; regulated by circadian rhythm and light exposure.

T3 / T4

Released from thyroid; targets receptors located on DNA; effects include increasing metabolic rate and O2 consumption, normal growth and development of bones and CNS; regulated by negative feedback preventing TSH production.

Calcitonin

Released from thyroid; targets bones and kidneys; effects include increasing calcium uptake and build-up in bones; regulated by increased Ca2+ levels in blood.

Parathyroid Hormone

Released from parathyroid; targets bones, kidneys, and digestive system; stimulates release of calcium from bones; regulated by decreased Ca2+ levels in blood.

Gastrin

Released from stomach; targets bloodstream and brain; effects include acid secretion (HCl); regulated by the amount of HCl present and triggered by food in stomach.

Secretin

Released from duodenum; targets pancreas and stomach; effects include digestive secretions and regulation of gastric acid; regulated by H+ and fatty acids in the duodenum.

CCK (Cholecystokinin)

Released from small intestine; targets gallbladder and pancreas; effects include release of bile; regulated by the amount of bile and triggered by fatty acids and amino acids.

Insulin

Released from pancreas; targets liver and muscles; effects include increasing uptake of glucose to be stored as glycogen; regulated by increased blood sugar levels.

Glucagon

Released from pancreas; targets liver; effects include increasing release of glucose from liver's glycogen stores; regulated by decreased blood sugar levels.

Estrogen

Released from ovaries; targets various tissues; effects include regulating the female reproductive system, menstrual cycle, and secondary sex characteristics; regulated by FSH and LH.

Progesterone

Released from adrenal cortex and corpus luteum (ovaries); targets uterus and mammary glands; effects include stimulating the lining of the uterus for fertilization and preparing breasts for milk production; regulated by LH.

Testosterone

Released from gonads; targets reproductive organs; effects include developing and maintaining male sexual characteristics and maturation; regulated by LH.

Steroid Hormones

Fatty hormones that are non-polar, allowing them to pass through membranes and change proteins directly.

Peptide/Amine Hormones

Water-soluble hormones that cannot diffuse through cell membranes and must bind to surface receptors to initiate cell signaling pathways.

Anterior Pituitary

Developed from the roof of the mouth, contains releasing hormones that trigger hormone release into the body.

Posterior Pituitary

Developed from the hypothalamus, has nerves that allow direct hormone release.

Positive Feedback

Amplifies changes leading to a greater response, commonly seen in labor and delivery.

Negative Feedback

Regulates change by maintaining stability, such as insulin release when blood sugar levels rise.

Adrenal Cortex Layers

Aldosterone is released from the glomerulosa (top layer), cortisol from the fasciculata (middle layer), and androgens from the reticulata (bottom layer).

Growth Hormone Diseases

Include acromegaly (excess GH in adulthood), GH excess during puberty (leading to tall stature), GH deficit (short stature), and dwarfism (decreased GH during childhood).

Goiter

Enlargement of the thyroid gland due to iodine deficit, leading to increased TSH levels and thyroid growth.

Cushing's Disease

High cortisol levels causing weight gain, high blood pressure, moon face, and buffalo hump.

Type 1 Diabetes

Insulin-dependent diabetes where the body does not secrete enough insulin.

Type 2 Diabetes

Insulin-resistant diabetes where the body secretes insulin but does not react to it.

Hyperthyroidism

Condition characterized by increased heart rate and high metabolism.

Hypothyroidism

Condition characterized by decreased heart rate and decreased metabolism.

Hyperparathyroidism

Excessive PTH secretion leading to increased calcium levels.

Hypoparathyroidism

Decreased PTH secretion leading to decreased calcium levels, resulting in cramping and muscle tetanus.