Download presentation
Presentation is loading. Please wait.
Published byLorena Johnston Modified over 9 years ago
1
Pathophysiology 4th year Endocrinology Course
2
Hormone Hormonal transport Hormonal degradation Membrane/ nuclear receptor Hypofunction Hyperfuction 2
3
Characteristics of endocrine glands Definition of hormone Transport Effects Elimination Regulation Purely endocrine organs Endocrine cells in other organs 3
4
4 The heart GI tract & derivatives The placenta The kidneys The skin Adipose tissue
5
Hormones are produced and secreted by endocrine cells in trace amounts. Hormones circulate in the blood to reach all tissues. Hormones serve as a chemical messenger carrying information Hormones react only with specific receptor molecules present in certain target cells/tissues. Hormones have high specificity and affinity receptor binding. Hormones act in catalytic quantities, frequently activating enzymes. A single hormone may have multiple effects on a single target tissue, or on several different target tissues. Hormones start a specific biological response. 5
6
Hormone actions are initiated at distant cells by binding to specific receptors. In addition to their direct main effects, hormones can have other effects: Synergistic effects Permissive effects Antagonistic effects 6
7
7 Feedback regulation Counteracting hormone Modification of the hormone Degradation/excretion Receptor down-regulation Inactivation of receptor Intracellular phosphatases
8
Synthesis and secretion Transport The quality and quantity of receptors Potential intracellular signaling Target tissue response Rate of degradation of hormones Individual levels of hormonal regulation: Synthesis and secretion Transport to the target cell Binding to specific receptors 8
10
Hyperfunction or hypofunction of the endocrine system Causes: Hormone hypersecretion or hyposecretion Disorders of the transport Disorders of the degradation Receptor dysfunction 10
11
"Down" and "up" regulation Low sensitivity Insensitivity (genetic mutations of receptor) Autoimmune destruction or stimulation Agonists or antagonists binding Disorders of complex receptor-G-protein Production of antibodies against receptors 11
12
Insufficient signal strength High signal strength under inappropriate conditions 1. Inappropriately high hormone levels. 2. Inappropriate receptor activation by agents other than the specific hormone 12
13
Decreased sensitivity of receptors Decreased secretion of hormones Increase in basal secretion Disorder of the response to feedback 13
14
Iatrogenic hypercortisolism Performance enhancing drugs Beer (phytoestrogens) Soya (fytoandrogens) 14
Similar presentations
© 2025 SlidePlayer.com. Inc.
All rights reserved.