Powerpoint regarding classification of hormones and their mechanism of action

1. Classification of Hormones
Presented By
Younis Ahmad Hajam
Pre- Ph.D Student
Department of Zoology,
Guru Ghasidas Vishwavidayalaya, Bilaspur.

2. Hormone
(Greek term “to spur on.”)
 Hormones are the chemical substances produced by specialized
tissue (endocrine gland) and secreted into the blood, where they are
carried to the target organs or cells.
 Main endocrine glands are:
• Hypothalamus(Master of master gland)
• Pituitary gland (Master gland)
• Pineal gland (Neuroendocrine gland)
• Thyroid gland
• Adrenal gland
• Gonads
• Endocrine part of pancreas (islets of langerhens)

3. Hormone features
• Chemical messengers
• Secreted by a specific gland
• Secreted directly into the blood stream
• Carried by the blood
• Acts on a specific target site distant from site of
secretion
• Secreted in minute quantities
• Acts via specific receptors to exert specific actions

4. Functions of Hormones
• Hormones coordinate all the biological activities within
an organism, these activities include :
– Metabolism
– Growth
– Reproduction
– Behavioral activities
• Affect contraction, relaxation, and metabolism of
muscles.
• Stimulate or inhibit cellular proliferation.
• Regulate excretion and reabsorption of inorganic
cations and anions from the kidneys.
• Have permissive actions on the action of the hormones.

5. Hormone classification

6. Basis of hormone classification
 On the basis of solubility
 On the basis of chemical nature
 On the basis of the function

7. I. On the basis of solubility.
i. Lipid soluble hormones: Steroids and thyroid hormones.
ii. Water soluble hormones: Peptides, proteins, amines.

8. Water soluble
hormones
Water soluble and lipid soluble hormones
Lipid soluble
hormones
gene
mRNA
peptide hormones
amino acid
derivatives
(epinephrine,
norepinephrine)
storage
secretion
cholesterol
steroid hormone
amino acid
derivative
(thyroid
hormone)
free hormone
free hormone
synthesis synthesis
binding protein
diffusion
plasma membrane
receptors
protein
target
DNA
mRNA
cellular response
Time
Hormone
Level
Time
Hormone
Level
ion flux
phosphorylation
second
messengers
(cAMP,
cGMP)
stimulus
secretion
cellular response

9. Steroid
Hormones
Receptors are
mainly in the
nucleus
Glucocorticoids
receptors are
mainly in the
cytoplasm
Steroid Hormones
Release from blood
circulation
steroid
progestrone
Diffuses into cytoplasm
Steroid DNA
receptor
Rough
endoplasmic
reticulum
mRNA
Protein
synthesis
Uterine glandular
endothelial cells
secretion

10. II. On the basis of their chemical nature
• Peptides: ACTH, Calcitonin, Glucagon, Vasopressin,
Oxytocin.
• Proteins: Insulin, and Parathormone (PTH).
• Amino acid derivatives: Catecholamine (epinephrine and nor-epinephrine),
thyroid hormones and melatonin.
• Steroids: (Derived from cholesterol) Hormones of adrenal
cortex and sex steroids.
• Glycoproteins: FSH &LH
• Derivatives of polyunsaturated fatty acids Derivatives :
Prostaglandins.

11. IV. On the basis of function
• Kinetic hormones: Those hormones which are involved in the
migration of pigment granules (melanin), muscle contraction
(oxytocin).
• Metabolic hormone: Those hormones which helps in the
control of metabolic functions e. g. thyroxin (T4 and T3, insulin,
growth hormone, parathyroid hormones etc.
• Morphometric hormones: Hormones which controls growth
and differentiation, e.g. Growth hormone, FSH, LH and
androgens (testosterone).

12. Mechanism of hydrophilic hormones via cyclic
AMP second messenger pathway

13. PIP2 AS SECOND MESSENGER

14. Behavioral hormones
• Hormones like testosterone develops secondary characters in
males
• Estrogen and progesterone helps in the development of the female
characters like breast development, deposition of fat in the hips,
deepening of voice etc.
• Maternal behavior is controlled by gonadal hormones and by
pituitary hormones
• Group behavior is effected by the release of pheromones into the
environment.

15. Signaling molecules act via following ways-
• Endocrine
• Paracrine
• Autocrine
• Intracrine
• Neuroendocrine
• Ectocrine (Pheramones)

16. Modes of delivery
Blood vessel
Distant target cells
Endocrine
Hormone secretion into
blood by endocrine gland
Secretory cell Adjacent target cell
Target sites on same cell
Paracrine
Autocrine