Endocrine system

1. ENDOCRINE SYSTEM
By
Mr. Vinayak R. Bodhankar
M. Pharm. (QA)

2.  INTRODUCTION
 The endocrine system consist of glands which are separated from one another & doesn’t have any anatomical
relationship.
 These glands are also called as ductless glands.
 Their secretions are called as Hormones.
 The secretion of hormones by other endocrine glands are controlled by Pituitary gland.
 Hence it is called master gland of the body.
 Important endocrine glands:
1. Pituitary
2. Thyroid
3. Parathyroid
4. Adrenal
5. Ovaries
6. Testes
7. Pineal

3.  NEGATIVE FEEDBACK MECHANISM
 Hypothalamus produces releasing factor which stimulate pituitary gland & they release anterior pituitary
hormones.
 The whole system is controlled by Negative feedback mechanism.
 Whenever there is low level of hormones in the blood, hypothalamus produces appropriate releasing factor
which stimulate release of hormones by anterior pituitary which in turns stimulates the target gland to produce
and release its hormones.
 As a result, blood level of hormones rises & this inhibit secretion of releasing factor.

4. Name of the Gland Hormones produced Function
PITUITARY GLAND
Pituitary - Anterior
Growth hormone Stimulate the growth of the body.
Prolactin Stimulate the milk production in the breast, stimulate the breast development during
pregnancy.
Thyrotropic hormone (TTH) Necessary for normal functioning of thyroid gland. It promotes the synthesis of thyroxine and
triiodothyronine.
Follicle stimulating hormone Stimulate follicular growth in ovaries and estrogen secretion.
Leutenizing hormone Triggers ovulation and development of Corpus luteum.
Adreno corticotropic hormone
(ACTH)
Regulate the levels of steroid hormones cortisol, which released from adrenal gland.
Pituitary –
Intermediate
Melanocyte stimulating hormone Protect the skin from UV rays, development of pigmentation and control of appetite.
Pituitary – Posterior
Oxytocin
Induces labour pain by contraction of uterine muscles and increases the production of
Prostaglandin which increases the contraction further.
Vasopressin (ADH)
Regulates the tonicity of the body fluids. Maintaining the volume of water in extracellular
fluids.
THYROID Tri iodo thyronine (T3) Regulation of body temperature, metabolism and heart rate. Essential for mental and physical
growth.
Control the amount of calcium in the blood.
Regulate blood calcium level. Increases absorption of Ca from intestine.
Thyroxine (T4)
Thyrocalcitonin
PARATHYROID Parathormone
TESTIS Testosterone Development of secondary sexual characteristics in males. Protein formation and muscle
development. Essential for the development of Sperms.
OVARIES
Progesterone Regulate the condition of inner lining of the uterus. Maintaining the early stages of pregnancy
and also MC.
Oestrogen Development of secondary sexual characteristics in females. Regulation of MC. In males, it
helps in maturation of sperm.
 ENDOCRINOLOGY

5. ADRENAL GLANDS a) Glucocorticoids
Hydrocortisone and
Corticosterone
Regulate carbohydrate metabolism. Influence metabolism of fats and proteins.
b) Mineralocorticoids
Aldosterone
Maintain electrolyte balance in the body. Reabsorption of calcium in the kidneys.
PANCREAS
(Islet of Langerhans)
Insulin Reduces blood glucose level. Promote conversion of glucose to glycogen. Promote
storage of fats & synthesis of Proteins.
Glucagon Raises blood glucose level.
Promote gluconeogenesis.