Abbr: TRH

Gland of origin: Hypothalamus

Major action: Stimulates secretion of TSH and prolactin

-T3 down-regulates TRH receptors in ant. pit.

Abbr: CRH

Gland of origin: Hypothalamus, in paraventricular nuclei

Major action: Stimulates action of ACTH

-when stimulated, CRH is released to hypothalamic-hypophysial portal blood

-second messenger is cAMP

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Abbr: GnRH

Gland of origin: Hypothalamus

Major action: Stimulates secretion of LH and FSH

Abbr: GHRH

Gland of origin: Hyporhalamus

Major action:Stimulates secretion of GH

Somatotropin release inhibitory hormone

(Somatostatin)

Abbr: SRIH

Gland of origin: Hypothalamus

Major action:Inhibits secretion of GH and TSH

-found in delta cells of stomach, intestines, Islets of Langerhans in pancreas

Prolactin-inhibiting factor

(Dopamine)

Abbr: PIF

Gland of origin: Hypothalamus

Major action:Inhibits secretion of prolactin

Abbr: TSH

Gland of origin: Anterior pituitary

Major action:stimulates synthesis and secretion of thyroxin, thyroid gland via cAMP

-chronic elevation of TSH causes hypertrophy of thyroid

-T3 down-regulates TRH, inhibiting TSH secretion

Abbr: FSH

Gland of origin: Anterior pituitary

Major action:increase growth of ovarian follicles

                  increase estrogen secretion

                  increases sperm maturation

Abbr: LH

Gland of origin: Anterior pituitary

Major action:increase ovulation, corpus luteum, estrogen and testosterone synthesis

Gland of origin: Anterior Pituitary

Major action:protein synthesis and overall growth, most important HM for normal growth

-secretion is pulsatile, inc. by GRHR sleep, stress, puberty, starvation, exercise, hypoglycemia

-dec by somatostatin, somatomedins, obesity, hyperglycemia, pregnancy

homologous with: prolactin and placental lactogen

Gland of origin: Anterior pituitary

Major action: lactogenesis, stimulates milk production and works with estrogen in breast development

-inhibits ovulation by releasing GnRH, inhibits spermatogenesis by dec. GnRH

-secretion inc by estrogen, breast-feeding, sleep, stress, TRH

-dec by dopamine, bromocriptine, somatostain, prolaction (Neg Feedback)

-homologous to GH

Abbr: ACTH

Gland of origin: anterior pituitary

Major action:increase synthesis and secretion of adrenal coritcoids

-formed from proopiomelanocortin (POMC)

-inc. steroid HM synthesis, stim. cholesterol desmolase, inc. conversion of cholesterol -> pregnenolone

-up-regulates its own receptors, causing inc. sensitivity to ACTH

-inc. levels cause hypertrophy of adrenal cortex

-second messenger is cAMP

beta-lipoprotein

Abbr: none

Gland of origin: Anterior pituitary

Major action: unknown in humans

Abbr: MSH

Gland of origin: Anterior pituitary

Major action: Inc. melanin synthesis

Gland of origin: Posterior pituitary, paraventricular nuclei of hypothalamus

Major action: contraction of myoepithelial cells cause milk ejection, uterine contraction (used to induce labor and reduce postpartum bleeding)

-suckling is the major stimulus, afferent fibers relay to hypothalamus

-secretion stimulated by: sight/sound of baby, and dilation of cervix and orgasm

Anti-diuretic Hormone

(Vasopressin)

Abbr: ADH

Gland of origin: Posterior pituitary, supraoptic nuclei of hypothalamus

Major action: Reg. serum osmolality by inc. H2O perm. of late distal tubules/ducts, inc. water reabsorption by the kidney

-constricts vascular smooth muscle

-secretion inc. by inc. serum, volume contraction, pain, strong nausea, hypoglycemia, nicotine, etc.

-dec. by dec. serum, ethanol,α-agonists, ANP

Abbr: T4

Gland of origin: Thyroid gland

Major action: skeletal growth, inc. metabolism

Abbr: T3

Gland of origin: thyroid gland

-less T3 is synthesized than T4, but more T3 is active

-T3 is 3x more potent than T4

-reverse T3 is inactive

-T3 down-regulates TRH receptors in ant. pit. and inhibits TSH secretion

Glucocorticoids

(cortisol)

Gland of origin: adrenal cortex

Major action: response to stress, inc. gluconeogenesis, anti-inflammatory

-up-regulates α-1 receptors on arterioles, inc. vasoconstrictor effect of norephinephrine 

-cortisol excess= inc. arterial pressure

-cortisol deficiency= dec. arterial pressure

Gland of origin: ovary

Major action: growth and development of female reproductive organs; follicular phase of menstrual cycle

Gland of origin: Ovary

Major action: Luteal phase of menstrual cycle

Gland of origin: testes

Major action: spermatogenesis; male secondary sex characteristics

Gland of origin: Parathyroid gland

Major action: inc. serum [Ca2+], dec. serum [phosphate]

-secreted from chief cells of parathyroid

-inc bone reabsorption, inc renal Ca2+ reabsorption, inc. intestinal Ca2+ reabsorb

-inhibits renal phosphate reabsorb

Gland of origin:thyroid gland, parafollicular cells

Major action: dec. serum [Ca2+]

secretion is stimulated by inc. in serum Ca2+

Aldosterone

(mineralcorticoids)

Gland of origin: adrenal cortex

Major action: inc. renal Na+ reabsorption; inc. renal K and H+ secretion

-under tonic control by ACTH

-separately regulated by RAAS and K+

-dec. blood vol -> inc. renin secretion, leading to RAAS

-aldosterone inc. renal Na absorption

-hyperkalemia= inc. aldosterone secretion

Gland of origin: Kidney (activation)

Major action: inc. intestinal Ca2+ absorption, inc. bone mineralization

Gland of origin: Pancreas (β-cells)

Major action: inc. glucose uptake into target cells, promotes formation of glycogen from glucose in liver, inhibits glycogenolysis

-overall effect on blood is dec blood glucose, dec. AA, dec fatty acids

-blood glucose concentration is major factor, inc. blood glucose stimulate insulin secretion

-secretion inc by: inc blood glucose, inc AA, inc. fat acids, glucagon, GIP, GH, cortisol

-is anabolic

-receptors are inc. in starvation, dec. in obesity

Gland of origin: Placenta

Major action: inc. estrogen and progesterone synthesis in corpus luteum of pregnacy

same action as growth hormone and prolactin during pregnancy