Endocrine Hormones

Hormones of the Posterior Pituitary

• Antidiuretic Hormone (ADH)

• Oxytocin

Antidiuretic Hormone (ADH)

Stimulus:

• Increased solute concentration of the blood (aka not enough water)

Inhibitors:

• Decreased solute concentration of the blood (aka too much water)

Released By:

• Posterior Pituitary

Target Tissues:

• Kidneys

• Brain

Effects:

• Water reabsorption from the kidney tubules

• Increases blood volume

Oxytocin

Stimulus:

• Stretching of the uterus

• Infant suckling at the nipple

Inhibitors:

• Lack of appropriate stimuli

Released By:

• Posterior Pituitary

Target Tissues:

• Uterus

• Mammary Glands

Effects:

• Uterine Contraction (Childbirth)

• Milk let-down reflex (Breastfeeding)

Hormones of the Anterior Pituitary

• Thyroid-Stimulating Hormone (TSH)

• Adrenocorticotropic Hormone (ACTH)

• Prolactin

• Luteinizing Hormone (LH)

• Follicle-Stimulating Hormone (FSH)

• Growth Hormone (GH)

Thyroid-Stimulating Hormone (TSH)

Stimulus:

• Thyrotropin-releasing hormone (TRH) from the hypothalamus

• Exposure to cold

• Stress

Inhibitors:

• Increased levels of thyroid hormones

• Somatostatin released from the hypothalamus

Released By:

• Anterior Pituitary

Target Tissues:

• Thyroid Gland

Effects:

• Growth and development of the thyroid gland

• Synthesis of thyroid hormones

Adrenocorticotropic Hormone (ACTH)

Stimulus:

• Corticotropin-Releasing Hormone (CRH) from the hypothalamus

• Stress

Inhibitors:

• Increased level of cortisol

• Increased level of aldosterone

Released By:

• Anterior Pituitary

Target Tissues:

• Adrenal Cortex

Effects:

• Growth and development of adrenal cortices

• Release of adrenal steroids and catecholamines

Prolactin

Stimulus:

• Prolactin-Releasing Hormone (PRH) from the hypothalamus

Inhibitors:

• Prolactin-Inhibiting Factor (dopamine) from the hypothalamus

Released By:

• Anterior Pituitary

Target Tissues:

• Mammary Glands

Effects:

• Development of mammary glands

• Milk production

Luteinizing Hormone (LH)

Stimulus:

• Gonadotropin-Releasing Hormone (GnRH) from the hypothalamus

Inhibitors:

• Increased levels of testosterone (males)

• Increased levels of estrogen or progesterone (females)

Released By:

• Anterior Pituitary

Target Tissues:

• Male Gonads (Testes)

• Female Gonads (Ovaries)

Effects:

• Males

  • Development of testes

  • Testosterone production

• Females

  • Development of ovaries

  • Production of estrogen and progesterone

  • Ovulation

Follicle-Stimulating Hormone (FSH)

Stimulus:

• Gonadotropin-Releasing Hormone (GnRH) from the hypothalamus

Inhibitors:

• Increased levels of testosterone (males)

• Increased levels of estrogens (females)

Released By:

• Anterior Pituitary

Target Tissues:

• Testes

• Ovaries

Effects:

• Production of factors that bind and concentrate testosterone

• Production of estrogens; maturation of ovarian follicles

Growth Hormone (GH)

Stimulus:

• Growth Hormone-Releasing Hormone (GHRH) from the hypothalamus

• Stress/Excercise

• Ingestion of Protein

• Fasting

Inhibitors:

• Somatostatin released from the hypothalamus

Released By:

• Anterior Pituitary

Target Tissues:

• Bone & Cartilage

• Muscle Tissue

• Livers

• Adipose Tissues

Effects:

• Gluconeogenesis

• Fat Breakdown (lipolysis)

• Protein Breakdown

• Production of insulin-like growth factor (IGF)

  • Stimulates cell division and protein synthesis

Hormones of the Pancreas

• Glucagon (Alpha Cells)

• Insulin (Beta Cells)

• Somatostatin (Delta Cells)

Glucagon

Stimulus:

• Low Blood Sugar

Inhibitors:

• High Blood Sugar

Released By:

• Pancreas

Target Tissues:

• Liver

Effects:

• Stimulates the breakdown of glycogen stores in the liver into glucose

Insulin

Stimulus:

• High Blood Sugar

Inhibitors:

• Low Blood Sugar

Released By:

• Pancreas

Target Tissues:

• Liver

• Body Tissue Cells (muscle, kidney, fat, etc.)

Effects:

• Stimulates the formation of glycogen stores in the liver from glucose molecules

• Stimulates glucose uptake from the blood for all other body cells

Hormones of the Thymus

• Thymosin

• Thymopoietin

• Assist in T lymphocyte maturation

Hormones of the Testes

• Testosterone

• Inhibin

Hormones of the Ovaries

• Estrogen

• Progesterone

• Inhibin

Hormones of the Hypothalamus

• Growth Hormone-Releasing Hormone (GHRH)

• Thyrotropin-Releasing Hormone (TRH)

• Corticotropin-Releasing Hormone (CRH)

• Gonadotropin-Releasing Hormone (GnRH)

• Prolactin-Releasing Hormone (PRH)

• Growth Hormone-Inhibiting Hormone (GIH)

• Prolactin-Inhibiting Hormone (PIH)

Thyroid Hormone (TH)

Stimulus:

• Release of TSH from the anterior pituitary

Released by:

• Thyroid

Target Tissues:

• All Body Cells

  • Increased metabolic rate

  • Increased amino acid uptake

  • Increased glucose uptake

• Liver

  • Increased glycogenolysis

  • Increased gluconeogenesis

  • Decreased glycogenesis

• Adipose Tissue

  • Increased lipolysis

  • Decreased lipogenesis

• Lungs

  • Increased breathing rate

• Heart

  • Increased heart rate

  • Increased force of contraction

Effects:

• Increased metabolic rate

• Nutrient release into blood

Hormones of the Adrenal Medulla

• Catecholamines

  • Epinephrine (adrenaline)

  • Norepinephrine (noradrenaline)

Catecholamines (Epinephrine & Norepinephrine)

Stimulus:

• Activation of the sympathetic division of the nervous system (emotional or physical stress)

Released By:

• Adrenal Medulla

Effects:

• Prolong the fight-or-flight response

  • Pupils dilate

  • Bronchioles dilate

  • Respiration rate increases

  • BP increases

  • Glucose & Lipid levels in the blood increase

  • Sweating increases

  • Digestive & Urine Output decrease

Hormones of the Adrenal Cortex

• Mineralcorticoids (Zona Glomerulosa)

  • Aldosterone

• Glucocorticoids (Zona Fasciculata)

  • Cortisol

• Gonadocorticoids (Zona Reticularis)

  • Testosterone

  • Estrogen

Cortisol

Stimulus:

• Release of corticotropin-releasing hormone (CRH) from the hypothalamus

Released By:

• Zona Fasciculata of the Adrenal Cortex

Target Tissues:

• Liver

• Adipose Tissues

• All Cells (except liver cells)

Effects:

• Liver

  • Increased glycogenolysis

  • Increased gluconeogenesis

  • Decreased glyconeogenesis

• Adipose Tissue

  • Increased lipolysis

  • Decrease lipogenesis

• All Cells

  • Stimulation of protein catabolism

  • Decreased glucose uptake

Aldosterone

Stimulus:

• Decreased blood pressure

• Increased potassium ion blood plasma levels

Released By:

• Zona Glomerulosa of the Adrenal Cortex

Effects:

• Retention of sodium ions and water

• Secretion of potassium ions

Parathyroid Hormone

Stimulus:

• Decrease in blood calcium levels

Inhibitors:

• Hypercalcemia

Released By:

• Parathyroid Glands

Target Tissues:

• Bone

• Kidneys

• Small Intestine

Effects:

• Release of calcium from bone tissue

  • Increase in osteoclast activity

• Decreased loss of calcium in urine

• Kidney releases enzymes to convert inactive calcidiol hormone into the active calcitriol hormone

• Increased calcium absorption from the small intestine

Hormones of the Pineal Gland

Melatonin