Organ

Product Secreted 

Sites of Action 

Biological Effects 

1. Brain

a) Neurosecretory cells of hypothalamus

Oxytocin

Uterus

Myoepithelial cells of mammary glands

Contraction of the uterus.

a) To facilitate the assent of spermatozoa

b) Delivery of the foetus ejection of milk

Vasopressin or anti-diuretic hormone (ADH)

Kidney

Increase absorption of water

Release factors

Anterior pituitary

Stimulate or inhibit the secretion of anterior pituitary hormones

b) Neurons

Neurotransmitters

Acetylcholine

Serotonin GABA

Adrenaline

Noradrenaline

Dopamine etc.

Neuron

Synapses

Neuromuscular junctions

Transmission of nerve impulse

c) Pineal body

Melatonin (synthesis and secretion promoted by darkness and inhibited by light)

Gonads

Darkening of skin

2. Pituitary       

a) Anterior lobe

Growth hormone or somatotrophic hormone (STH)

Almost all organs of the body

Growth of bones, cartilage muscles and viscera promote synthesis of proteins in tissues influences carbohydrate and fat metabolism; mobilizes body mechanisms in situations of nutritional scarcity.

ACTH

Adrenal

Adipose tissue

Synthesis and secretion of adrenal hormones mobilization of fats

TSH

Thyroid

Synthesis and secretion of thyroid hormones

Gonadotrophins

Ovaries in females FSH, LH

Development of Testes in males

follicles, ovulation: secretion of estrogens and progesterone spermatogenesis, development and function of testis, secretion of testosterone.

Prolactin

Mammary glands

Development of mammary glands in combination with other hormones, estrogens, progesterone, STH, adrenal corticoids, lactation

3. Thyroid

Thyroxine (T4)

Several organs

Increase in basal metabolic rate and in consumption of oxygen by cells: growth promotion and development.

Calcitonin

Lower the level of calcium in blood

4. Parathyroid

Parathyroid hormone

Bones Kidney

Mobilizes calcium from bones to raise serum levels of calcium; increases excretion of phosphate

5. Thymus

characterized humoral factors

Partially from bone marrow

Stem cells

Development of precursor cells to lymphocytes eventually competent for cell-mediated immunity and having role in production of antibodies.

6. Pancreas

Insulin

Muscles, liver, adipose tissue and many other organs

Reduces blood glucose levels by promoting its uptake by peripheral cells; Increases utilization of carbohydrates; increases deposition of glycogen, stimulates lipogenesis: anabolic effects on protein synthesis

Glucagon

Liver, adipose tissue

Hyperglycaemic factor mobilizes liver

glycogen stores to replenish blood glucose level; Enhances conversion of amino acids to carbohydrates.

7. Adrenal cortex

Glucocorticoids principal member (hydrocortisone) mineral corticoids (aldosterone) androgens

Several organs

Retention of sodium and excretion of potassium; Maintenance of extracellular volume; cardiovascular functions:   muscular and kidney function adaptation to stress (trauma, cold, heat, toxins, infections, fasting forced exercise, etc.). Immunosuppressive action promotion of gluconeogenesis anti-inflammatory action

8. Adrenal

medulla

Epinephrine Norepinephrine Dopamine

Heart muscles, liver and other organs

Increase the heart rate, raise systolic blood pressure; mobilize glucose from liver and muscles: anxiety

9. Ovaries

Estrogens

Female reproductive organs and secondary sex organs, uterus, vagina, mammary glands, pituitary brain                            

Promotes growth of uterus, mammary glands   and vaginal epithelium: feedback effect on secretion of gonadotrophins influences behaviour and psychic patterns.               

Progesterone

-do

Acts synergistically and in some cases antagonistically to estrogens: preparation of the uterus for implantation of the blastocyst; maintenance of pregnancy: regulation of the accessory organs

10. Tests

Androgens

Male reproductive and accessory organs, muscles

Spermatogenesis, seminal plasma secretions, hair patterns, skeletal configuration, voice changes, regulation of sebaceous gland activity: general anabolic hormone stimulates protein Synthesis

11. Stomach

Gastrin

Gastrin glands

Stimulation of gastric secretions

12. Duodenum

Secretin

Pancreas

Stimulates the secretion of pancreatic fluids.

13. Intestines

Pancreozymin

Enterogastrone 

Cholecystokinin

Pancreas

Stomach

Gall bladder

Release of bile.

14. Kidney

Erythropoetin

Reninangiotensin

Hematopoietic organs cardiovascular system, adrenals, kidney

Stimulation of the formation of blood cells vasoconstriction elevation of blood pressure Increased cardiac output autonomous system.