Major Endocrine Glands and Hormones

Releasing and Inhibiting Hormones

Gland: Hypothalamus

Molecular Class: Peptide

Target: Anterior Pituitary

Function: Regulates secretion of anterior pituitary hormones

Thyroid-Stimulating Hormone (TSH)

Gland: Anterior Pituitary

Molecular Class: Peptide

Target: Thyroid

Function: Stimulates secretion of thyroid hormones and growth of the thyroid

Adrenocorticotropic Hormone (ACTH)

Gland: Anterior Pituitary

Molecular Class: Peptide

Target: Adrenal Cortex

Function: Stimulates secretion of glucocorticoids by adrenal cortex

Follicle-Stimulating Hormone (FSH)

Gland: Anterior Pituitary

Molecular Class: Peptide

Target: Gonads

Function: Stimulates egg growth and development and secretion of sex hormones in females; stimulates sperm production in males

Luteinizing Hormone (LH)

Gland: Anterior Pituitary

Molecular Class: Peptide

Target: Gonads

Function: Regulates ovulation in females and secretion of sex hormones in males

Prolactin (PRL)

Gland: Anterior Pituitary

Molecular Class: Peptide

Target: Mammary Glands

Function: Stimulates breast development and milk secretion

Growth Hormone (GH)

Gland: Anterior Pituitary

Molecular Class: Peptide

Target: Bone, Soft Tissue

Function: Stimulates growth of bone and soft tissues; helps control metabolism of glucose and other fuel molecules; promotes protein synthesis

Melanocyte-Stimulating Hormone (MSH)

Gland: Anterior Pituitary

Molecular Class: Peptide

Target: Skin

Function: Promotes darkening of the skin

Endorphins

Gland: Anterior Pituitary

Molecular Class: Peptide

Target: Pain Pathways of the Peripheral Nervous System

Function: Inhibits perception of pain

Antidiuretic Hormone (ADH)

Gland: Posterior Pituitary

Molecular Class: Peptide

Target: Kidneys

Function: Raises blood volume and pressure by increasing water reabsorption in urine

Oxytocin

Gland: Posterior Pituitary

Molecular Class: Peptide

Target: Uterus and Mammary Glands

Function: Promotes uterine contractions and stimulates milk ejection from breasts

Calcitonin

Gland: Thyroid

Molecular Class: Peptide

Target: Bone

Function: Lowers calcium concentration in blood

Thyroxine (T4) and Triiodothyronine (T3)

Gland: Thyroid

Molecular Class: Amine

Target: Most Cells

Function: Increases metabolic rate, growth, development, and maturation

Parathyroid Hormone (PTH)

Gland: Parathyroid

Molecular Class: Peptide

Target: Bone, Kidneys, and Intestines

Function: Raises calcium concentration in blood and stimulates vitamin D activation

Epinephrine and Norepinephrine

Gland: Adrenal Medulla

Molecular Class: Amine

Target: Sympathetic receptor sites in body

Function: Reinforces sympathetic nervous system; fight-or-flight response

Aldosterone (Mineralocorticoid)

Gland: Adrenal Cortex

Molecular Class: Steroid

Target: Kidney Tubules

Function: Helps control body’s saltwater balance by increasing sodium reabsorption and potassium excretion in kidneys

Cortisol (Glucocorticoid)

Gland: Adrenal Cortex

Molecular Class: Steroid

Target: Most body cells; particularly muscle, liver, and adipose cells

Function: Increases blood glucose by promoting breakdown of proteins and fats; chronic stress

Androgens (like Testosterone)

Gland: Testes

Molecular Class: Steroid

Target: Various tissues

Function: Control male reproductive system development and maintenance

Oxytocin

Gland: Testes

Molecular Class: Peptide

Target: Uterus

Function: Promotes uterine contractions when seminal fluid is ejaculated into the vagina during sexual intercourse

Estrogens (like Estradiol)

Gland: Ovaries

Molecular Class: Steroids

Target: Breasts, Uterus, and other Tissues

Function: stimulates maturation of sex organs at puberty and development of secondary sexual characteristics

Progesterone

Gland: Ovaries

Molecular Class: Steroid

Target: Uterus

Function: Prepare and maintain uterus for implantation of fertilized egg and the growth and development of embryo

Glucagon (Alpha Cells)

Gland: Pancreas (Isles of Langerhans)

Molecular class: Peptide

Target: Liver cells

Function: Raises glucose concentration in blood; promotes the release of glucose from glycogen stores and production from carbohydrates

Insulin (Beta Cells)

Gland: Pancreas (Isles of Langerhans)

Molecular Class: Peptide

Target: Most cells

Function: Lowers glucose concentration in blood; promotes storage of glucose, fatty acids, and amino acids

Melatonin

Gland: Pineal Gland

Molecular Class: Amine

Target: Brain, Anterior Pituitary, Reproductive Organs, Immune System

Function: Helps synchronize body’s biological clock with day length; may inhibit gonadotropins and initiation of puberty