best slides for medical students

1. Hormones
Roshan Ali
Assistant Professor
IBMS, KMU

2. Course Contents
• Introduction of hormone
• Classes of Hormones
• o Steroid Hormone
• o Amino Hormone
• o Peptide Hormone
• Mode of Action of steroid & peptide hormones
• cardiac, pineal and gastrointestinal hormones.

3. Introduction to hormone
• Hormones are chemical messengers that are secreted directly into the
blood, which carries them to organs and tissues of the body to exert
their functions.

4. Classes of hormones
• amines, these are simple molecules. E.g. epinephrine and
norephinephrine
• proteins and peptides which are made from chains of amino acids.
E.g. Insulin and glucagon
• steroids which are derived from cholesterol. E.g. Androgens and
Estrogens

5. Mode of Action of steroid & peptide
hormones
• Hormones are released into the bloodstream from which they will diffuse into the interstitial fluid surrounding the target cells and into the blood
stream to travel to target sites.
• The target cell has receptors specific to a given hormone and will be activated by either a lipid-soluble (permeable to plasma membrane) or water-
soluble hormone (binds cell-surface receptor).
• Lipid-soluble hormones (steroid hormones and hormones of the thyroid gland) diffuse through the plasma membrane to enter the target cell and
bind to a receptor protein that will in turn activate expression of specific genes that influence specific physiological cell activities.
• Water-soluble hormones (such as polypeptides, proteins and most amino acid hormones) bind to a receptor protein on the plasma membrane of the
cell.
• The ligand-bound receptor protein will activate other membrane-bound proteins to give rise to cyclic AMP (cAMP) which then triggers an enzyme that
generates specific cellular changes.
• The ligand-bound receptor protein will activate other membrane-bound proteins to give rise to cyclic AMP (cAMP) which then triggers an enzyme that
generates specific cellular changes.
• Water-soluble hormones (such as polypeptides, proteins and most amino acid hormones) bind to a receptor protein on the plasma membrane of the
cell.
• The ligand-bound receptor protein will activate other membrane-bound proteins to give rise to cyclic AMP (cAMP) which then triggers an enzyme that
generates specific cellular changes.
• Source: Boundless. “Mechanisms of Hormone Action.” Boundless Anatomy and Physiology. Boundless, 21 Jul. 2015. Retrieved 09 Dec. 2015 from
https://www.boundless.com/physiology/textbooks/boundless-anatomy-and-physiology-textbook/the-endocrine-system-16/hormones-
150/mechanisms-of-hormone-action-774-807/

6. Cardiac, pineal and gastrointestinal hormones
• In response to a rise in blood pressure, the heart releases two peptides: Atrial Natriuretic Peptide (ANP) This
hormone of 28 amino acids is released from stretched atria. Brain Natriuretic Peptide (BNP) This hormone
(32 amino acids) is released from the ventricles.
• The pineal gland, also known as the pineal body, conarium or epiphysis cerebri, is a small endocrine gland in
the vertebrate brain.
• It produces melatonin, a serotonin derived hormone, which affects the modulation of sleep patterns in both seasonal and
circadian rhythms.
• Cholecystokinin: Stimulates gallbladder contraction and intestinal motility; stimulates secretion of pancreatic
enzymes, insulin, glucagon, and pancreatic polypeptides
• Gastrin: Gastrins stimulate the secretion of gastric acid, pepsinogen, intrinsic factor, and secretin; stimulate
intestinal mucosal growth; increase gastric and intestinal motility
• Secretin: Stimulates pancreatic secretion of HCO3, enzymes and insulin; reduces gastric and duodenal
motility, inhibits gastrin release and gastric acid secretion

7. Thank You