Produced by endocrine (“ductless”) glands and secreted into the bloodstream. Endocrine hormones may affect a wide array of target cells to produce multiple effects. Two types: peptides (small proteins) and steroids (lipids).

1. ENDOCRINE SYSTEM
RAVI RANJAN
AssISSTANT Professor
Dept. of Pharmacy Practice
ISF COLLEGE OF PHARMACY
Website: - www.isfcp.org
Email:
ISF College of Pharmacy, Moga
Ghal Kalan,nGT Road, Moga- 142001, Punjab, INDIA
Internal Quality Assurance Cell - (IQAC)

2. CONTENTS
INTRODUCTION
2

3. What are endocrine hormones?
1 2 3
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1. Chemical signals from one
cell to remote target cells.
2. Chemicals for direct cell-
to-cell communication.
3. Chemicals that cross a
gap between to adjacent
cells.

4. Messenger Molecules
 Cells must communicate with one another to
coordinate cell processes within tissues and to maintain
homeostasis.
 Cell-to-cell communication is carried out via
messenger molecules.

5. Three types of
chemical signals
are used for cell-
to-cell
communication.

6. Endocrine hormones
 Produced by endocrine (“ductless”) glands and
secreted into the bloodstream.
 Endocrine hormones may affect a wide array of
target cells to produce multiple effects.
 Two types: peptides (small proteins) and steroids
(lipids).

7. Hormones and Receptors

8. Peptide Hormones
 Peptide hormones do not enter the cell directly. These
hormones bind to receptor proteins in the cell
membrane.
 When the hormone binds with the receptor protein, a
secondary messenger molecule initiates the cell
response.
 Because peptide hormones are water soluble, they often
produce fast responses.

9. (cytoplasm)
(nucleus)
peptide or amino
acid-derived
hormone
(first messenger)
(extracellular
fluid)
cyclic AMP-
synthesizing
enzyme
cyclic AMP
ATP
inactive
enzyme
(second messenger)
active
enzyme
reactant
product
plasma membrane
nuclear
envelope
receptor
The hormone binds to
a receptor on the plasma
membrane of a target cell
1
The activated enzymes
catalyze specific reactions
4
The second
messenger activates
other enzymes
3
Hormone–receptor binding
activates an enzyme that catalyzes
the synthesis of a second messenger,
such as cyclic AMP
2

10. Steroid Hormones
 Steroid hormones enter through the cell membrane and
bind to receptors inside of the target cell.
 These hormones may directly stimulate transcription of
genes to make certain proteins.
 Because steroids work by triggering gene activity, the
response is slower than peptide hormones.

11. gene
plasma
membrane
ribosome
hormone receptor
steroid hormone
mRNA
(nucleus)
RNA polymerase
DNA
(cytoplasm)
new protein
(extracellular
fluid)
A steroid hormone
diffuses through the
plasma membrane
The hormone binds to a
receptor in the nucleus or to
a receptor in the cytoplasm
that carries it into the nucleus
The hormone–receptor
complex binds to DNA and
causes RNA polymerase to
bind to a nearby promoter
site for a specific gene
RNA polymerase catalyzes
the transcription of DNA into
messenger RNA (mRNA)
The mRNA leaves the
nucleus, then attaches to a
ribosome and directs the
synthesis of a specific protein
product
1
2
3
4
5
nuclear
envelope

12. Pituitary Hormones
Pituitary Hormone Functions
Follicle-stimulating hormone Stimulates egg maturation in the ovary and release
of sex hormones.
Lutenizing hormone Stimulates maturation of egg and of the corpus
luteum surrounding the egg, which affects female
sex hormones and the menstrual cycle.
Thyroid-stimulating hormone Stimulates the thyroid to release thyroxine.
Adrenocorticotropic hormone Causes the adrenal gland to release cortisol.
Melanocyte-stimulating hormone Stimulates synthesis of skin pigments.
Growth hormone Stimulates growth during infancy and puberty.
Antidiuretic hormone Signals the kidney to conserve more water.
Oxytocin Affects childbirth, lactation, and some behaviors.

13. Endocrine Hormones
Gland Hormones Functions
Thyroid Thyroxine Regulates metabolism
Calcitonin Inhibits release of calcium from the bones
Parathyroi
ds
Parathyroid
hormone
Stimulates the release of calcium from the bones.
Islet cells
(in the
pancreas)
Insulin Decreases blood sugar by promoting uptake of
glucose by cells.
Glucagon Increases blood sugar by stimulating breakdown of
glycogen in the liver.
Pineal
gland
Melatonin Sleep cycles, reproductive cycles in many mammals.

14. Testes Testosterone Regulates sperm cell production and secondary sex
characteristics.
Ovaries Estrogen Stimulates egg maturation, controls secondary sex
characteristics.
Progesterone Prepares the uterus to receive a fertilized egg.
Adrenal
cortex
Epinephrine Stimulates “fight or flight” response.
Adrenal
medulla
Glucocorticoids Part of stress response, increase blood glucose
levels and decrease immune response.
Aldosterone Regulates sodium content in the blood.
Testosterone (in
both sexes)
Adult body form (greater muscle mass), libido.

15. Hormones Everywhere
 Many other organs besides the endocrine glands
produce hormones.
 Kidneys produce several hormones that regulate blood
pressure, which is essential for kidney function.
 The digestive system produces several hormones that
regulate appetite.

16.  THANK YOU